小林 欣夫

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.