小林 欣夫

Background-It is not clear why some plaque ruptures lead to acute coronary syndromes (ACS) but others do not. Methods and Results-We analyzed 80 plaque ruptures in 74 patients and compared culprit lesions of ACS patients with nonculprit lesions of ACS patients and lesions of non-ACS patients; both culprit and nonculprit plaque ruptures were studied in 6 of 54 ACS patients. Intravascular ultrasound findings suggesting thrombus were observed more frequently in culprit lesions of ACS patients (n=35) compared with nonculprit lesions of ACS patients (n=19) and lesions of non-ACS patients (n=26): 60% versus 32% versus 8% (P<0.001). At the minimal lumen site, smaller lumen areas (3.3±1.5 versus 5.4±2.6 versus 6.1±2.0 mm(2), P<0.001) and greater area stenosis (61+/-15% versus 50+/-14% versus 46+/-18%, P=0.002) and plaque burden (80+/-8% versus 71+/-8% versus 69+/-10%, P<0.001) were observed in culprit lesions of ACS patients compared with nonculprit lesions of ACS patients and lesions of non-ACS patients. Lesions were longer (18.7±6.4 versus 154.9±6.1 versus 12.0±4.9 mm, P<0.001) and rupture site remodeling indices were greater (1.26+/-0.21 versus 1.24+/-0.21 versus 1.09+/-0.05, P=0.002). Independent predictors of culprit plaque ruptures in ACS patients were smaller minimum lumen areas (P=0.02) and presence of thrombus (P=0.01). Conclusions-Ruptured plaques in culprit lesions of ACS patients have smaller lumens; greater plaque burdens, area stenosis, and remodeling indices; and more thrombus. Plaque rupture itself does not lead to symptoms. The association of plaque rupture with a smaller lumen area and/or thrombus formation causes lumen compromise and leads to symptoms.

The present study evaluated in-hospital and 1-year outcomes after multivessel stenting in patients aged greater than or equal to80 (75 patients, 241 lesions) and <80 years (894 patients, 2,678 lesions). Despite a high technical success rate of multivessel stenting, octogenarians had higher in-hospital cardiac and noncardiac complication rates and a higher mortality rate at 1-year clinical follow-up compared with their younger counterparts. (C)2003 by Excerpta Medica, Inc.

Percutaneous coronary intervention (PCI) devices are much more expensive in Japan than in the United States, but their prices were reduced in April 2002. This study evaluated the impact of that change in the price of PCI devices on medical expenses. In-hospital costs of 22 consecutive patients who underwent elective single-vessel PCI without a debulking procedure before April 2002 were collected and the in-hospital cost of each patient was recalculated by applying the current prices of the PCI devices and those in the USA. For patients treated with PCI before April 2002, the in-hospital cost was Y1,456,375+/-358,781, but when the current price is used, the in-hospital cost is estimated to be Y1,355,812+/-313,237 (7% reduction). If the prices of the devices were reduced to those in USA, there would be a 53% reduction (Y689,417+/-99,139). Although the change in the price of PCI devices in April 2002 has reduced in-hospital costs, the devices are still much more expensive in Japan than in the USA. Further reduction of the price is required to make PCI more cost-effective.

Negative remodeling is commonly observed in stenotic coronary lesions. It is unknown whether negative remodeling is an early or late event. This study was designed to elucidate when negative remodeling occurs in the development of coronary stenosis. Remodeling was assessed by preintervention intravascular ultrasound in 104 native coronary lesions with intermediate stenosis (20% to 60% of diameter stenosis measured by quantitative coronary angiography). Positive remodeling was defined as lesion external elastic membrane (EEM) cross-sectional area (CSA) greater than the proximal reference, intermediate remodeling as lesion EEM CSA between those of the proximal and distal references, and negative remodeling as lesion EEM CSA less than the distal reference. Positive, intermediate, and negative remodeling were observed in 18%, 32%, and 50%, respectively, of lesions with intermediate stenosis. Lesions with negative and intermediate remodeling had more hard plaque compared with those with positive remodeling (79% vs 70% vs 42%, p = 0.02). Calcium was more frequent in lesions with negative and intermediate remodeling than in those with positive remodeling (52% vs 55% vs 16%, p = 0.01). Lesions with negative remodeling had smaller EEM CSA (11.5 +/- 5.2 2 vs. 13.7 +/- 3.4 vs 14.5 +/- 5.6 mm, p = 0.03) and less plaque (7.9 +/- 4.6 vs 10.8 +/- 3.4 vs 10.8 +/- 4.9 mm(2), p = 0.004) compared with positive and intermediate re-modeling lesions, although lumen CSA (3.7 +/- 1.7 vs 2.8 +/- 0.8 vs 3.6 +/- 1.3 mm(2), P = 0.1) and area stenosis (57 +/- 15% vs 59 +/- 14% vs 56 +/- 10%, p = 0.7) were similar. Negative remodeling is frequently observed in lesions with intermediate stenosis. This suggests that negative remodeling occurs early in lesion formation. (C) 2003 by Excerpta Medica, Inc.

Transforming growth factor-beta (TGF-beta) has been implicated in the development of diabetic glomerulopathy. In order to evaluate a role of Smad3, one of the major signaling molecules downstream of TGF-beta, in the pathogenesis of diabetic glomerulopathy, Smad3-null mice were made diabetic with streptozotocin injection and analyzed 4 weeks after induction of diabetes. Electron microscopy revealed that the thickness of glomerular basement membrane (GBM) in wild-type diabetic mice was significantly higher than that in non-diabetic mice, whereas no appreciable GBM thickening was found in Smad3-null diabetic mice. Urinary albumin excretion was dramatically increased in wild-type diabetic mice, whereas Smad3-null diabetic mice did not show any overt albuminuria. Northern blotting revealed that mRNA levels of fibronectin and alpha 3 chain of type IV collagen (alpha 3Col4) in renal cortex of wild-type diabetic mice were approximately twice as much as those of non-diabetic mice, whereas their mRNA levels were not increased in Smad3-null diabetic mice. Real-time polymerase chain reaction (PCR) also confirmed diabetes-induced upregulation of fibronectin and alpha 3Col4 in glomeruli of wild-type mice. Glomerular expression of TGF-beta 1, as assessed by real-time PCR, was enhanced to a similar degree in wild-type and smad3-null diabetic mice, indicating that the observed differences between wild-type and Smad3-null mice are not attributable to difference in the expression of TGF-beta 1. These data clearly demonstrate a critical role of Smad3 in the early phase of diabetic glomerulopathy. This may be due at least partly to the present findings that diabetes-induced upregulation of fibronectin and alpha 3Col4 is dependent on Smad3 function.

Correlations between baseline hemodynamic and oximetric variables during an invasive exercise test and an improvement in peak oxygen uptake (peak (V) over circle o2) after exercise training (ET) were examined in 20 patients who participated in a cardiac rehabilitation program after acute myocardial infarction (AMI). Peak (V) over circle o2 significantly increased by 23+/-21% (p<0.01) after ET and the improvement best correlated with the change in O-2 extraction fraction ([arterial O-2 content-venous O-2 content] /arterial O-2 content) during an exercise test before ET (r=-0.61, p<0.01). Exercise capacity was improved to a greater extent by ET in patients with a smaller increase in O-2 extraction fraction during an exercise test before ET. Thus, O-2 extraction fraction during an exercise test before ET may be a useful predictor of the improvement in exercise capacity after ET in post-AMI patients.

Angiographic criteria to select patients for optimal balloon angioplasty.

The present study evaluated the effect of stent overdilatation on lumen size and intimal hyperplasia at follow-up. Stent overdilatation results in larger follow-up lumens despite larger late lumen loss due to greater intimal hyperplasia.

Although previous randomized trials 1-2 have demonstrated lower restenosis rates in selected lesions with coronary stents than with conventional balloon angioplasty. in-stent restenosis remains an important clinical problem.(3,4) Previous serial angiographic studies(5,6) showed that lumen loss after stenting occurred within 6 months. On the other hand, improvements in lumen dimensions between 6 months and 2 to 3 years have been demonstrated by angiography.(6-9) Serial (postintervention and at 6-month follow-up) intravascular ultrasound (IVUS) studies(10,11) have demonstrated that coronary stenting eliminates negative arterial remodeling, and thus intimal hyperplasia is solely responsible for in-stent restenosis. However, little has been reported about changes in intimal hyperplasia that occur beyond this 6-month period. This serial IVUS study evaluated the changes in intimal hyperplasia between 6 and 12 months after stent placement.

We identified 1,215 patients (322 women, 26.5%) who received glycoprotein (GP) IIb/IIIa inhibitors during 1,852 coronary artery stenting procedures. Compared with men, women had similar rates of in-hospital ischemic events and vascular complications, and similar 1-month major adverse cardiac events rates. Therefore. use of the GP Ilb/IIIa inhibitors appears to eliminate the previously noted "disadvantages" in women with respect to early clinical outcome after interventional procedures.

Objectives The purpose of this study, was to evaluate the approach of intravascular ultrasound (IVUS)-guided percutaneous transluminal coronary, angioplasty (PTCA) with spot stenting (SS) for the treatment of long coronary, lesions. Background Treating long coronary lesions with balloon angioplasty, results in suboptimal short- and long-term outcomes. Full lesion coverage with traditional stenting (TS) has been associated with a high restenosis rate. Methods We prospectively evaluated a consecutive series of 130 long lesions (>15 mm) in 101 patients treated with IVUS-guided PTCA and SS. The results were compared with those of TS int a matched group of patients. Coronary angioplasty was performed with a balloon to vessel ratio of 1:1, according to the IVUS media-to-media diameter of the vessel at the lesion site, to achieve prespecified IVUS criteria: lumen cross-sectional area (CSA) greater than or equal to5.5 mm(2) or greater than or equal to 50% of the vessel CSA at the lesion site. The stents were implanted only, in the vessel segment where the criteria were not met. Results In the SS group, stents were implanted in 67 of 130 lesions, and the mean stent length was shorter than that of lesions in the matched TS group (10.4 +/- 13 mm vs. 32.4 +/- 13 mm, p<0.005). The 30-day major adverse cardiac event (MACE) rate was similar (5%) for both groups. Angiographic restenosis was 25% with IVUS-guided SS, as compared with 39% in the TS group (p<0.05). Follow-up MACE and target lesion revascularization rates were lower in the SS group than in the TS group (22% vs. 38% [p<0.05] and 19% vs. 34% [p<0.05], respectively). Conclusions Intravascular ultrasound-guided SS for the treatment of long coronary, lesions is associated with good acute outcome. Angiographic restenosis and follow-up MACE rates were significantly lower than those with TS. (J Am Coll Cardiol 2001;38:1427-33) (C) 2001 by the American College of Cardiology.

We report five cases treated with brachytherapy through the internal mammary artery (IMA) for in-stent restenosis at the distal anastomosis (n = 3) and in the left anterior descending coronary artery beyond the distal anastomosis (n = 2). After angioplasty, catheter-based gamma radiation was performed. There was no delivery failure of the radiation system. All cases had angiographic success and no procedural or in-hospital complications. (C) 2001 Wiley-Liss, Inc.

In 382 de novo lesions in native coronary arteries, clinical and angiographic predictors of a large discrepancy in vessel diameter between intravascular ultrasound and quantitative angiography were evaluated. The discrepancy was highest in diabetics, in vessels <3.0 mm on angiography, and in the proximal segments of the coronary tree.

We report treatment of a lesion with coronary stent underexpansion due to heavily calcified plaque. Conventional balloon angioplasty was attempted for in-stent restenosis, but the lesion was undilatable despite 25-atm inflation pressure. Intravascular ultrasound (IVUS) revealed stent underexpansion due to heavily calcified plaque. Rotational atherectomy was performed using a stepped burr approach, after which repeat IVUS revealed marked ablation of the stent-calcium complex. Adjunctive balloon angioplasty then easily resulted in full balloon and stent expansion, with an excellent angiographic and IVUS result. The patient's hospital course was uneventful. Cathet Cardiovasc Intervent 2001; 52:208-211. (C) 2001 Wiley-Liss, Inc.

Background: It is known that left ventricular systolic function at rest does not correlate well with exercise capacity of patients with heart failure. However, the contribution of left ventricular diastolic dysfunction, especially during exercise, to exercise capacity of cardiac patients remains to be determined. Objective: To determine the impact of left ventricular systolic and diastolic function during exercise on exercise capacity of patients with left ventricular dysfunction after myocardial infarction. Methods: A symptom-limited exercise test was performed with measurements for hemodynamics and uptake of oxygen (VO2) of 26 men who had previously suffered myocardial infarction. These patients were divided into two groups according to their peak VO2 (group 1 with peak VO2 ≥ 16ml/kg per min, n= 13 and group 2 with peak VO2 &lt 16 ml/kg per min, n= 13). Pulmonary arterial pressure, left ventricular and systemic arterial pressure, and cardiac output were measured at rest and during exercise. Results: At rest, there was no difference between the two groups in terms of hemodynamic parameters except for minimal dP/dt, minimal left ventricular pressure (LVP) and time constant for decay of left ventricular pressure (τ). During peak exercise, cardiac output, left ventricular end-diastolic pressure (EDP), minimal dP/dt, minimal LVP, and τ for the two groups were significantly different. Furthermore, peak VO2O2 was significantly correlated with τ, minimal LVP, minimal dP/dt, EDP, and maximal dP/dt during peak exercise for the whole group of patients. Conclusion: Left ventricular diastolic function during exercise, i.e. diastolic reserve, may be an important determinant of exercise capacity of patients with left ventricular dysfunction after myocardial infarction. © 2001 Lippincott Williams &amp Wilkins.

A 64-year-old male with unstable angina underwent direct stenting in the proximal and mid-left anterior descending coronary artery (LAD) lesions. Although coronary angiography showed a good result, intravascular ultrasound imaging revealed a dissection flap protruding through the struts of the stent in the proximal LAD. Another stent was deployed in the first stent (stent-in-stent) to seal it. The patient's in-hospital course was uneventful. Subacute stent thrombosis was not observed.

Background-The aim of this study was to use serial volumetric intravascular ultrasound to evaluate the effect of gamma -radiation on recurrent in-stent restenosis. Methods and Results-After successful reintervention, patients were randomized to receive either Ir-192 Or placebo. Intravascular ultrasound studies with motorized pullback (0.5 mm/s) were performed immediately after irradiation and at 8-month follow-up in 70 patients. Paired volumetric analysis of the stented segment and of 5-mm proximal and distal reference segments was performed; this included measurements of the external elastic membrane, lumen, plaque and media (external elastic membrane minus lumen), stent, and intimal hyperplasia (stent minus lumen). Baseline proximal reference, stent, and distal reference measurements were similar in both groups. The changes in proximal and distal reference measurements of the external elastic membrane, plaque and media, and lumen areas were similar in both groups. However, the decrease in stented segment lumen volume was less in the Ir-192 patients than the placebo patients (-25+/-34 mm(3) versus -48+/-42 mm(3); P=0.0225), and the increase in the volume of intimal hyperplasia in the stented segment was less in the Ir-192 patients than in the placebo patients (28+/-37 mm(3) versus 50+/-40 mm(3); P=0.0352). When averaged over the length of the stented segment (32+/-13 mm versus 33+/-14 mm; P=0.9), the increase in mean area of intimal hyperplasia was 0.8+/-1.0 mm(2) in the Ir-192 group and 1.6+/-1.2 mm(2) in the control group (P=0.0065). Late stent-vessel wall malapposition was noted in one placebo patient and no Ir-192 patients. Conclusions-gamma -Radiation therapy can effectively prevent recurrent in-stent restenosis by inhibiting neointimal formation within the stent. At the stent edge, there were no significant differences between Ir-192 and placebo patients.

We report a new stenting technique employed in 10 patients to treat lesions immediately proximal to a bifurcation (pseudobifurcation). A stent is mounted on two balloon catheters and advanced into the lesion immediately proximal to the bifurcation until the distal portion of the balloon catheters enters each branch at the bifurcation. This is followed by kissing balloon inflation for stent deployment. In all 10 cases, the final angiogram showed a good result at the lesion site and no ostial compromise of any of the branches. Cathet. Cardiovasc. Intervent. 51:347-351, 2000. (C) 2000 Wiley-Liss, Inc.

The present study evaluated the cost of coronary stenting compared with conventional balloon angioplasty in Japan. Procedural cost was estimated as the sum of the procedural fee and the cost of devices such as angioplasty balloon and stent. The data such as the number of balloon catheters and stents used, and the rate of crossovers that was shown by the Stent Restenosis Study (STRESS) were applied to calculate the costs of stenting and conventional balloon angioplasty. For the estimation of hospital room and nursing costs, the length of the in-hospital stay was estimated at 7 days. The costs of procedures such as laboratory and radiological tests were determined based on routine coronary intervention at Chiba University Hospital. The rates of target lesion revascularization in the STRESS trial (conventional balloon angioplasty: 21%, stenting: 15%) were used to calculate the cost during follow up. The in-hospital costs of conventional balloon angioplasty and stenting were estimated to be Yen 982,300 and Yen 1,416,893, respectively. The overall costs, including follow-up cost, of conventional balloon angioplasty and stenting were estimated to be Yen 1,188,583 and Yen 1,564,238, respectively. The in-hospital cost of stenting is higher compared with conventional balloon angioplasty because of greater balloon use and direct stent cost. Lower target lesion revascularization reduces the cost difference between conventional balloon angioplasty and stenting, but the higher initial cost of stenting is not fully offset.

A 65-year-old male with unstable angina underwent coronary angiography, which revealed a significant stenotic lesion in the right coronary artery. This narrowing was subsequently treated with the Multi-Link stent. During the balloon inflation associated with stent deployment, balloon rupture occurred and resulted in overdilatation of an elastic membrane in the stent delivery system. This, in turn, resulted in coronary dissection, which required treatment with further stenting.

After placing a stent in the main vessel of a bifurcation lesion, it is often necessary to perform further balloon inflation or stent placement through the stent struts in order to treat a lesion of the secondary vessel or side branch. This balloon inflation with dilatation through the cells of the stent in the main vessel results in stent strut disfigurement. This disfigurement causes various degrees of stenosis within the main vessel secondary to stent strut deformity. The degree of strut deformity, and therefore stenosis, may vary significantly depending on stent design and structure. A model of a bifurcation lesion with an angle of 45°was created from acrylic resin. The diameters of the main vessel and the secondary vessel were both 3.5 mm. Deployment of the Palmaz-Schatz stent (PS, n = 5), NIR stent (n = 5), or Multi-Link stent (n = 5) was performed in the main vessel with a 3.5-mm balloon catheter inflated to 6 atm. A second 3.5-mm balloon catheter was then inflated to 6 atm through the stent struts of the main vessel and into the ostium of the secondary vessel. The minimal lumen diameter (MLD) and cross-sectional area (CSA) at the ostium of the side branch and the stenosis within the main vessel were then measured, taking into account the stent deformity that occurred. Kissing balloon dilatation with two 3.5-mm balloon catheters was then performed and the stenosis secondary to stent deformity in the main vessel was remeasured. The MLD of the Multi-Link stent at the side-branch ostium was greater compared with those of the Palmaz-Schatz stent or the NIR stent (2.4 ± 0.1, 1.6 ± 0.1, 1.7 ± 0.1 mm, P &lt 0.01) and CSA (4.9 ± 0.5, 2.7 ± 0.3, 2.5 ± 0.3 mm2, P &lt 0.01). Balloon inflation through the stent struts caused stent deformity that resulted in some degree of stenosis within the stent of the main vessel in all three stent types. Kissing balloon inflation reduced, but never eliminated, this stenosis. The percent stenosis in the main vessel secondary to stent deformity (PS 34% ± 9%, NIR 25% ± 8%, Multi-Link 34% ± 7%, NS) and residual stenosis postkissing balloon inflation (PS 12% ± 1%, NIR 10% ± 3%, Multi-Link 14% ± 3%, NS) were not significantly different among these three stents. At the side-branch ostium, the MLD and CSA were significantly greater for the Multi-Link stent compared with those of the Palmaz-Schatz or NIR stent. Balloon inflation through the stent struts caused stent deformity that resulted in stenosis within the stent in the main vessel. Kissing balloon inflation reduced this stenosis, but some residual stenosis always remained. The stenoses within the main vessel did not differ among the three stent types.

Previous studies have shown that levels of plasma brain natriuretic peptide (BNP) increase in an early phase of acute myocardial infarction. However, the relations between plasma BNP levels and left ventricular remodelling, which occurs long after acute myocardial infarction, are not fully understood. Venous plasma BNP levels were measured 2, 7, 14, 30, 90 and 180 days after the onset of acute myocardial infarction in 21 patients. Left ventricular end-diastolic volume index (EDVI, ml/m2) in acute (5 days) and chronic (6 months) phases were assessed by electron-beam computed tomography using Simpson's method. The remodelling group (n = 9) was defined by an increase in EDVI ≥ 5 ml/m2 relative to the baseline value. Plasma BNP levels on days 2, 7, 14, 30 and 90 were significantly higher in the remodelling group than in the non-remodelling group (n = 12, P &lt 0.05). Sustained elevation of plasma BNP levels was noted from day 2 (61 ± 12 pmol/l) to day 90 (55 ± 12 pmol/l) and significantly decreased on day 180 (24 ± 3 pmol/l) in the remodelling group. In contrast, plasma BNP levels significantly decreased from day 2 (25 ± 4 pmol/l) to day 90 (9 ± I pmol/l) and reached a steady level thereafter in the non-remodelling group. Plasma BNP levels on day 7 correlated positively with an increase in EDVI (r = 0.70, P &lt 0.001) from the acute to chronic phase. More importantly, the sustained elevation of plasma BNP (percentage decrease smaller than 25%) from day 30 to day 90 identified patients in the remodelling group with a sensitivity of 100% and a specificity of 83%. In conclusion, not only the high levels of plasma BNP in an acute phase, but also the sustained elevation of plasma BNP in a chronic phase, may be associated with progressive ventricular remodelling occurring long after acute myocardial infarction.

Objectives. Stent implantation reduces restenosis in vessels greater than or equal to 3 mm compared with balloon angioplasty, but few data are available for stents implanted in vessels <3 mm. The aim of this study was to evaluate immediate and follow-up patient outcomes after stent implantation in vessels <3 mm compared to stent implantation in vessels greater than or equal to 3 mm. Methods. Between March 1993 and May 1996, a total of 1,298 consecutive patients (1,673 lesions) underwent coronary stenting. The study population was divided into two groups based on angiographic vessel diameter. In case of multivessel stenting, patients were randomly assigned only one lesion. Group I included 696 patients (696 lesions) in whom stents were implanted in vessels greater than or equal to 3 mm, and group II included 602 patients (602 lesions) in whom stents were implanted in vessels <3 mm. Results. There was no difference in procedural success (95.4% in group I and 95.9% in group II), or subsequent subacute stent thrombosis (1.5% in group I and 1.4% in group II p = NS). The postprocedure residual diameter stenosis was 3.31 +/- 12.4% in group I and -2.45 +/- 16.2% in group II. Angiographic follow-up was performed in 75% of patients, restenosis occurred in 19.9% of patients in group I and 32.6% in group II (p <0.0001). Absolute lumen gain was significantly higher in group I compared to group II, but absolute late lumen loss was similar in the two groups (1.05 +/- 0.91 mm in group I vs. 1.11 +/- 0.85 mm in group II, p NS). Subsequently, the loss index was more favorable in group I [0.45 vs. 0.56; p = 0.0006). Independent predictors of freedom from restenosis by multivariate logistic regression in the total population were: larger baseline reference diameter (odds ratio 2.032 p = 0.006, larger postprocedure minimal stent cross-sectional area (odds ratio 1.190, p = 0.0001) and shorter lesions (odds ratio 1.037, p = 0.01). At long term clinical follow up, patients with small vessels had a low er rate of event free survival (63% vs. 71.3%, p = 0.007), Conclusions. Coronary stenting can be performed in small vessels with a high success rate and low incidence of stent thrombosis. However, the long-term angiographic and clinical outcome of patients undergoing stent implantation in small vessels is less favorable than that of patients with large vessels. (J Am Coll Cardiol 1998;32:1610-8) (C)1998 by the American College of Cardiology.

The present study evaluated acute and late results with stenting following directional coronary atherectomy (DCA) for the lesions in the left anterior descending coronary artery (LAD). Between April 1995 and January 1997, 200 LAD lesions with greater than or equal to 3 mm reference vessel diameter were treated with coronary stents, The lesions were divided as to whether or not DCA was performed before stenting; 1) stenting alone (n = 163) and 2) debulking and stenting (n = 37). There were no significant differences in the incidences of complications except for non-Q-wave myocardial infarction that was more frequent in patients with debulking and stenting than in those with stenting alone (13.5% vs, 2.4%, P < 0.05), A greater acute lumen gain (2.85 +/- 0.66 vs. 2.25 +/- 0.60 mm, P < 0.01) and minimal lumen diameter (3.64 +/- 0.56 vs. 3.15 +/- 0.41 mm, P < 0.01) after stenting were observed in patients with debulking and stenting than in those with stenting alone. At follow-up patients with debulking and stenting continued to have a greater minimal lumen diameter (2.88 +/- 0.72 vs, 2.15 +/- 0.85 mm, P < 0.01) and had a lower restenosis rate (6.3% vs. 23.1%, P < 0.05) than those with stenting alone. Stenting following DCA appears to be advantageous in the LAD lesions with greater than or equal to 3 mm reference vessel diameter. (C) 1998 Wiley-Liss, Inc.

Background-Coronary stenting has reduced restenosis in focal de novo lesions, but its impact has been less pronounced in complex lesion subsets. Preliminary data suggest a role for plaque burden in promoting intimal hyperplasia after stent implantation. The aim of this study was to test the hypothesis that plaque removal with directional atherectomy before stent implantation may lower the intensity of late neointimal hyperplasia, reducing the incidence of in-stent restenosis. Methods and Results-Seventy-one patients with 90 lesions underwent directional atherectomy before coronary stenting. Intravascular ultrasound-guided stenting was performed in 73 lesions (81%). Clinical success was achieved in 96% of patients. Procedural complications were as follows: emergency bypass surgery in I patient (1.4%), who died 2 weeks later; Q-wave myocardial infarction in 2 patients (2.8%); and non-Q-wave myocardial infarction in 8 patients (11.3%). None of the patients had stent thrombosis at follow-up. Angiographic follow-up was performed in 89% of eligible patients at 5.7+/-1.7 months. Loss index was 0.33 (95% CI, 0.26 to 0.40), and angiographic restenosis was 11% (95% CI, 5% to 20%). Clinical follow-up was performed in all patients at 18+/-3 months. Target lesion revascularization was 7% (95% CI, 3% to 14%). Conclusions-Directional atherectomy followed by coronary stenting could be performed with good clinical success rate. Also, these data point to a possible reduction in angiographic restenosis and a significant reduction in the need for repeated coronary interventions. Therefore, a randomized clinical trial seems appropriate to lest the validity of this approach.

Objectives. This study sought to compare the short- and longterm outcomes of elderly patients undergoing coronary artery stenting with those of younger patients and to determine the long-term clinical outcome and survival of elderly patients post stent implantation. Background. Elderly patients undergoing coronary revascularization are considered a high-risk group. Few data exist that relate the results of stenting in treating coronary artery disease in the elderly population. Methods. All elderly patients greater than or equal to 75 years of age who underwent coronary artery stenting between March 1993 and July 1997 (n = 137) at our center were compared to the patients <75 who underwent coronary artery stenting during the same time period (n = 2,551). Long-term clinical follow-up and survival were determined for the elderly group. Results. Elderly patients presented,vith lower ejection fractions (54% vs. 58%, p = 0.0001), more unstable angina (47% vs. 28%, p = 0.0001), and more multivessel disease (78% vs. 62%, p = 0.0001) than younger patients. These older patients had higher rates of procedure related complications including procedural myocardial infarction (MI) (2.9% vs. 1.7%, p = 0.2), emergency CABG (3.7% vs. 1.4%, p = 0.04), and death (2.2% vs. 0.12%, p = 0.0001). Angiographic follow-up, obtained in both groups, demonstrated significantly higher restenosis rates in the elderly versus younger patients (47% vs. 28%, p = 0.0007). Longer term clinical follow-up, which was obtained only in the elderly group, showed that at a mean follow-up period of 12 months post coronary stenting, elderly survival free from death, MZ, revascularization and angina was 54% and that their overall survival was 91%. Subanalysis of the elderly patients who died showed much higher incidence of combined unstable angina (80%), prior MI (60%), lower ejection fraction (46%), multivessel disease (100%) and complex lesions (100%) than the overall group. Conclusions. Elderly patients who undergo coronary artery stenting have significantly higher rates of procedural complications and worse six month outcomes than younger patients, especially those who present with combined unstable angina, history of MI, EF < 50%, multivessel disease and complex lesions. Overall survival in the elderly population at 12 months postcoronary artery stenting was 91% and event-free survival was 54%. (J Am Coil Cardiol 1998;32:577-83) (C) 1998 by the American College of Cardiology.

Objective. This pilot study was performed to evaluate the feasibility and safety of intrawall delivery of long acting steroids before stent implantation, testing the efficacy of this treatment in reducing intimal hyperplasia in lesions at high risk for restenosis. Methods. In 24 patients (40 lesions) local intrawall drug delivery of methylprednisolone acetate, using a new catheter device, was attempted before elective stent implantation. Treated lesions were compared to a matched control group. Results. Lesions were classified AHA/ACC type C in 47% of cases, had a mean lesion length of 13.6 +/- 9.1 mm, and a mean vessel diameter of 2.85 +/- 0.44 mm. In 9 cases (25%) chronic total occlusions were treated. Methylprednisolone acetate (mean 60 +/- 23 mg) was delivered in 36 lesions (21 patients; delivery success 90%) in the remaining 4 lesions (10%) the delivery device did not cross the lesion. After drug delivery 46 stents were implanted (1.2 stent/lesion; stented segment length 30.1 +/- 18.8 mm) using high pressure for stent expansion (mean 16.4 +/- 3.1 atm). Intracoronary ultrasound guidance was used in 64% of eases. Procedural and in-hospital complications were: Two non Q wave myocardial infarctions (8%) and one (3%) subacute stent thrombosis. Angiographic follow-up was obtained in all 36 treated lesions (100%) and the angiographic restenosis rate (greater than or equal to 50% diameter stenosis) was 39%. A reduction of the incidence of restenosis compared to the matched control group was not observed. Conclusions. Long acting steroids could be delivered locally with high success and low complication rates. The restenosis rate remained high in a subset of unfavorable lesions with high risk for restenosis.

This study was designed to assess the cardioprotective effect of intravenous nicorandil, a potassium channel opener, in preventing reperfusion injury in acute myocardial infarction. Seventy patients were treated with placebo or nicorandil concomitant with reperfusion therapy in a prospective, randomized, double-blind fashion within 6 h after the onset of acute myocardial infarction. Nicorandil was administered before reperfusion as a 2- rag bolus iv injection followed by continuous infusion of 2-6 mg/h for the next 3 h. Thirty-six patients (17 in the placebo group, 19 in the nicorandil group) who demonstrated both complete occlusion of an infarct-related vessel before treatment and successful reperfusion were included in the final analysis. No significant changes in left ventricular ejection fraction were observed between the immediate and chronic phases in each group. In the analysis of regional ventricular function, the placebo group did not show any significant change in regional chord shortening (26.8±8.2 vs 24.3±7.3%, NS) or hypocontractile perimeter (36.4±28.2% vs 28.3±24.8%, NS) between immediate and chronic phase left ventriculograms. In contrast, in the nicorandil group, a significant increase in regional chord shortening (21.5±11.0% vs 25.8±11.3%, p&lt 0.05) and a significant decrease in hypocontractile perimeter (33.3±19.6% vs 25.6±24.3%, p&lt 0.05) were observed in the chronic phase left ventriculogram. Thus, nicorandil may be a useful adjunctive therapy for preserving myocardial contractile function in patients with acute myocardial infarction undergoing reperfusion therapy.

The kissing stenting using a new technique in two patients is reported. A stent was positioned at the ostium of the side branch, Another stent was advanced into the main vessel until the center of the stent was positioned near the origin of the side branch. The stent at the ostium of the side branch was deployed and the balloon and the guidewire were removed from the side branch. Thereafter, the stent in the main vessel was deployed. The follow-up angiogram of those patients showed no restenosis in both the vessels. (C) 1998 Wiley-Liss, Inc.

There is little information on how previous angina influences in- hospital deaths secondary ta acute myocardial infarction (MI). This study evaluated the causes of in-hospital deaths in MI patients with and without previous angina. A total of 2,264 consecutive patients were admitted to our hospital due to acute MI. These patients were divided into 2 groups according to the presence or absence of prior MI. Both groups were further divided according to the presence or absence of previous angina. The causes of in- hospital deaths were classified into 4 categories: (1) cardiogenic shock or congestive heart failure, (2) cardiac rupture, (3) arrhythmia, and (4) other causes. In patients with a first MI, the in-hospital mortality rate was lower in patients with previous angina than those without (6.9% vs 11.4%, p &lt 0.01). There was no significant difference between these patients with and without previous angina in in-hospital deaths due to cardiogenic shock or congestive heart failure, arrhythmia, or other causes. Death due to cardiac rupture was less frequent in patients with previous angina (1.4% vs 5.0%, p &lt 0.01). In patients with prior MI, the in-hospital mortality rate was lower in patients with than without previous angina (17.7% vs 25.3%, p &lt 0.05). In contrast to patients with their first MI, there was a trend toward a lower incidence of in-hospital death due to cardiogenic shock or congestive heart failure in patients with previous angina (12.8% vs 19.0%, p = 0.05). There were no significant differences in in-hospital deaths due to cardiac rupture, arrhythmia, and other causes between the 2 subgroups. In multivariate analysis, previous angina was an independent predictor of in-hospital death. Thus, in-hospital deaths after acute MI in patients with previous angina were less because of less cardiac rupture in patients with a first MI and less cardiogenic shock or congestive heart failure in patients with prior MI.

To investigate the relation between plasma brain natriuretic peptide (BNP) and progressive ventricular remodeling, we measured plasma BNP and atrial natriuretic peptide (ANP) in 30 patients with acute myocardial infarction on days 2, 7, 14, and 30 after the onset. Left ventricular end- diastolic volume index (EDVI), end-systolic volume index (ESVI), and ejection fraction (EF) on admission and 1 month after the onset were assessed by left ventriculography. Changes in EDVI (ΔEDVI), ESVI (ΔESVI), and EF (ΔEF) were obtained by subtracting respective acute-phase values from corresponding chronic-phase values. Plasma ANP on days 2 and 7 showed only weak correlations with AEDVI (r = 0.48 and 0.54 both p &lt 0.01), whereas plasma BNP on day 7 more closely correlated with ΔEDVI (r = 0.77 p &lt 0.001). When study patients were divided into two groups according to plasma BNP on day 7, the group with BNP higher than 100 pg/ml showed greater increases in left ventricular volume and less improvement in EF compared with the other group with BNP lower than 100 pg/ml (ΔEDVI = 10.4 ± 8 vs -3.4 ± 9 ml/m2, ΔESVI = 6.2 ± 7 vs -4.9 ± 5 ml/m2, and ΔEF = 1.0% ± 4% vs 4.9% ± 5% p &lt 0.05, respectively). Multiple regression analysis revealed that only plasma BNP on day 7, but not ANP, peak creatine phosphokinase level, left ventricular end-diastolic pressure, or acute-phase EF, correlated independently with ΔEDVI (p &lt 0.01). These results suggest that plasma BNP may be a simple and useful biochemical marker for the prediction of progressive ventricular remodeling within the first 30 days of acute myocardial infarction.

Background: Doppler echocardiography is a valuable noninvasive method for evaluating of the occurrence and degree of either prosthetic valve stenosis or regurgitation. By using serial Doppler echocardiographic examination, we evaluated the incidence and the mode of the Carpentier- Edwards pericardial valve (CEPX) dysfunction compared with that of the Ionescu-Shiley valve (IS). Methods and Results: After aortic and/or mitral valve replacement 80 patients with CEPX and 111 with IS underwent Doppler echocardiography at intervals of at least 2 years after surgery. The average durations of follow-up were 6.1 ± 2.9 years for patients with CEPX and 7.2 ± 3.0 years for those with (S. Bioprosthetic valve stenosis was defined as reduced excursion of the bioprosthetic valve leaflets and peak gradient ≤60 mm Hg after aortic valve replacement and mean gradient ≤7 mm Hg after mitral valve replacement. Bioprosthetic valve regurgitation caused by bioprosthetic valve dysfunction was defined as grade ≤3 transvalvular regurgitation. In the aortic position, although there was no significant difference in the actuarial rate of freedom from bioprosthetic valve stenosis between patients with IS and those with CEPX (10 years after surgery, 88% ± 7% vs 90%, Ns), bioprosthetic regurgitation caused by bioprosthetic valve dysfunction occurred less frequently in patients with CEPX than in those with IS (10 years after surgery, 86% vs 54% ± 9%, p &lt 0.05). In the mitral position, bioprosthetic valve stenosis occurred more frequently in patients with CEPX than in those with IS (10 years after surgery, 54% ± 11% vs 72% ± 8%, p &lt 0.01). Although grade ≤3 transvalvular bioprosthetic regurgitation occurred later in patients with CEPX than in those with IS, there was no significant difference in the actuarial rate of freedom from that regurgitation between patients with CEPX and those with IS (10 years after surgery, 63% ± 10% vs 54% ± 7%, NS). Conclusions: For aortic valve replacement, CEPX has good long-term durability because of the low incidence of bioprosthetic regurgitation. For mitral valve replacement, long-term durability of CEPX is poor, although medium-term durability is satisfactory.

A 25-year-old Japanese woman was admitted due to acute inferior myocardial infarction. Coronary angiography showed complete occlusion of the proximal right coronary artery and vague calcification distal to the complete occlusion. Using ultrafast computed tomography, two coronary artery aneurysms in the right coronary artery that could not be detected by coronary angiography were visualized.

Background and aims of the study: Little comparative information exists on the outcome of valve replacement with bioprostheses or mechanical valves in the elderly. This study was carried out to make such a comparison. Methods: Follow up data were examined from 219 patients aged ≤65 years who underwent aortic and/or mitral valve replacement using bioprosthetic (n = 67) or mechanical valve (n = 152) between April 1979 and December 1993. The mean follow up periods were 6.3 ± 2.8 years after bioprosthesis and 4.9 ± 2.1 years after mechanical valve implantation. Results: Although the actuarial rate of structural deterioration was higher in patients with bioprosthetic valves than in those with mechanical valves (58% versus 100% freedom at 10 years after surgery, p &lt 0.01), no such prosthesis-related difference was seen in the subgroup of patients aged ≤70 (100% versus 100% at nine years, p = N.S.). The actuarial rate of major bleeding was higher after mechanical valve implantation than after bioprosthetic valve placement (90% versus 100% freedom at 10 years, p &lt 0.05) this lower rate with bioprosthetic valves was maintained in patients aged ≤70 (78% versus 100% at nine years, p &lt 0.05). There were no significant differences in the incidences of thromboembolism and bacterial endocarditis between the two valve types. Conclusions: Structural degeneration of bioprosthetic devices was a major problem in patients aged 65-70 years, but it was essentially negligible in those aged ≤70 years. Anticoagulant-related bleeding was a major problem with mechanical valves in both age groups. Therefore, for patients older than 70 years, valve replacement with a bioprosthesis appears to be the method of choice.

Although the present study revealed that previous angina improved in- hospital outcome, no further benefit was observed once the patients left the hospital. The worse long-term prognosis was associated with multivessel coronary disease in patients with previous angina.

Objective: This study evaluated the pre- and postoperative exercise capacity in adult patients with atrial septal defect (ASD) associated with hemodynamic variables. Methods: Adults (71) with ASD underwent symptom- limited exercise tests. Peak O2 uptake (Peak VO2) and % peak VO2, that is the percentage of predicted value, were measured. These patients were divided into three groups according to pulmonary-to-systemic flow ratio (Qp/Qs) and systolic pulmonary arterial pressure (PAs): Group A: QpQs ≤ 3, PAs ≤ 50 mm Hg, Group B: Qp/Qs &gt 3, any PAs, Group C: Qp/Qs ≤ 3, PAs &gt 50 mm Hg. Exercise test was repeated in 22 patients after surgical closure of ASD (mean 4.6 ± 2.0 months). Results: Peak VO2 was significantly lower in group B (P &lt 0.01) and group C (P &lt 1.01) than in group A (19.3 ± 5.7, 17.6 ± 3.6, 27.6 ± 6.3 ml/min/kg, respectively). In patients except those in group C, there were a weak negative correlation between PAs and % peak VO2 (r = 0.61) and a significant negative correlation between Qp/Qs and % peak VO2 (r = 0.86). Postoperative peak VO2 increased significantly in group A (272 ± 5.1 31.1 ± 5.1 ml/min/kg, P &lt 0.05) and group B (16.7 ± 3.3 21.5 ± 2.1 ml/min/kg, P &lt 0.01. However, there was no significant difference between pre- and postoperafive peak VO2 in group C (16.8 ± 1.3 17.8 ± 2.8 ml/min/kg, NS). Conclusions: In ASD patients except those with small or moderate left-to-right shunt and high pulmonary arterial pressure, there was a significant negative correlation between Qp/Qs and peak VO2 corrected by age and gender. Patients with large left-to-right shunt and/or high pulmonary arterial pressure had reduced exercise capacity. However, exercise capacity in patients with large left-to-right shunt increased after closure of ASD regardless of whether they had high pulmonary arterial pressure.

Background: There is little information about changes in mitral valve function caused by thickening and stiffening of artificial chordae during follow up. Using serial echocardiographic examination, we evaluated thickening and stiffening of artificial chordae and the effect of those changes on mitral valve function. Methods and Results: Between November 1986 and Novemher 1993, 40 patients underwent mitral valve repair with artificial chordae using glutaraldehyde-tanned xenograft pericardium (GTXP) or polytetrafluoroethylene suture (PTFE). Seven GTXP patients and 20 PTFE patients underwent serial echocardiographic examination after surgery and were included in the final analysis. Thickening and stiffening of the artificial chordae were classified according to echocardiographic changes after surgery: grade 1, no change grade 2, thickening and/or stiffening without impairment of the motion of the mitral valve leaflet and grade 3, thickening and stiffening that impaired motion of the mitral valve leaflet. The mean follow-ups in patients with GTXP and PTFE were 6.0 and 3.6 years, respectively. During follow-up, there were 2 GTXP patients with grade 2 thickening and stiffening and 4 patients with grade 3. There were 6 PTFE patients with grade 2 thickening and stiffening and 2 patients with grade 3. Grade 3 occurred earlier in GTXP than in PTFE patients (P&lt .05). Mitral valve area in GTXP patients decreased from 2.5±0.4 to 2.1±0.3 cm2 (P&lt .05) however, mitral valve area in PTFE patients showed no significant change during follow-up (2.1±0.4 to 2.0±0.4 cm2, P=NS). Conclusions: Although mitral valve repair with artificial chordae is useful, more attention should be paid to mitral valve function resulting from thickening and stiffening of artificial chordae.

A 64-year-old patient with silent myocardial ischemia after anterior myocardial infarction was treated with directional coronary atherectomy, balloon angioplasty, and placement of Palmaz-Schatz stent. An unexpanded Palmaz-Schatz stent was retained in the left main coronary artery and was treated successfully with a nitinol goose-neck snare. After this procedure, another Palmaz-Schatz stent was successfully implanted without any complications.

Objectives. This study sought to evaluate bioprosthetic valve dysfunction in the tricuspid position by serial Doppler echocardiography. Background. Few reports on the long-term results of tricuspid valve replacement with bioprosthetic valves are evaluated by serial Doppler echocardiography. Methods. Between September 1979 and December 1993, 95 patients underwent tricuspid valve replacement with bioprosthetic valves at our facility. Sixty patients who underwent serial Doppler echocardiographic examination at intervals of at least 2 years after operation were included in the final analysis. These patients were followed up from 1.5 to 13.0 years (mean 5.8 ± 2.5). Results. The actuarial rates of freedom from bioprosthetic valve stenosis and regurgitation at 10 years were 46% and 51%, respectively. The prevalence of bioprosthetic valve stenosis and regurgitation increased progressively in a linear manner beginning 1 or 2 years after tricuspid valve replacement. Right heart failure developed during follow-up in 20 of the 25 patients with bioprosthetic valve dysfunction. Conclusions. The long-term durability of bioprosthetic valves in the tricuspid position was substantially lower in our study than that reported in previous studies. Tricuspid bioprosthetic valve dysfunction increased progressively in a linear manner beginning 1 to 2 years after tricuspid valve replacement.