井上 貴裕

BACKGROUND: Acute myocardial infarction (AMI) is a major scenario for the use of an intra-aortic balloon pump (IABP), particularly when complicated by cardiogenic shock, although the utilization of mechanical circulatory support devices varies widely per hospital. We evaluated the relationship, at the hospital level, between the volume of IABP use and mortality in AMI.Methods and Results: Using a Japanese nationwide administrative database, 26,490 patients with AMI undergoing primary percutaneous coronary intervention (PCI) from 154 hospitals were included in this study. The primary endpoint was the observed-to-predicted in-hospital mortality ratio. Predicted mortality per patient was calculated using baseline variables and averaged for each hospital. The associations among PCI volume for AMI, observed and predicted in-hospital mortality, and observed and predicted IABP use were assessed per hospital. Of 26,490 patients, 2,959 (11.2%) were treated with IABP and 1,283 (4.8%) died during hospitalization. The annualized number of uses of IABP per hospital in AMI was 4.5. In lower-volume primary PCI centers, IABP was more likely to be underused than expected, and the observed-to-predicted in-hospital mortality ratio was higher than in higher-volume centers. CONCLUSIONS: A lower annual number of IABP use was associated with an increased mortality risk at the hospital level, suggesting that IABP use can be an institutional quality indicator in the setting of AMI.

BACKGROUND: Stroke care units provide advanced intensive care for unstable patients with acute stroke. We conducted a survey to clarify the differences in stroke care units between urban and regional cities and the relationship between the number of stroke care unit beds and neurologists. METHODS: This retrospective observational study was conducted in 2,857 and 4,184 hospitals in urban and regional cities in 47 provinces of Japan, respectively, between January 2020 and August 2023. Tokyo and ordinance-designated cities in provinces were defined as urban cities, and those without such cities were defined as regional cities. The primary endpoint was the presence or absence of a stroke care unit. RESULTS: Multiple linear regression analysis revealed that the presence of stroke care units was significantly associated with the number of neurosurgical specialists. Receiver operating characteristic curve analysis was performed to predict the number of personnel required for stroke care unit installation based on the number of neurosurgical specialists. The area under the receiver operating characteristic curve, Youden index, sensitivity, and specificity were 0.721, 0.483, 0.783, and 0.700, respectively. CONCLUSIONS: Our study underscores the indispensability of SCUs in stroke treatment, advocating for a strategic allocation of medical resources, heightened accessibility to neurosurgical specialists, and a concerted effort to address geographic and resource imbalances. The identified cutoff value of 8.99 neurosurgical specialists per 100,000 population serves as a practical benchmark for optimizing SCU establishment, thereby potentially mitigating stroke-related mortality.

BACKGROUND: We aimed to evaluate the length of hospital stay following total knee arthroplasty to determine the impact of relevant factors using data from the Diagnosis Procedure Combination database. METHODS: This was a retrospective observational study. The study cohort included 5,831 patients who had osteoarthritis of the knee and had undergone total knee replacement between February 2018 and October 2022 at 38 hospitals. RESULTS: Multivariate analysis showed that the factors influencing the length of stay included: age (p < 0.001), height (p < 0.001), weight (p = 0.049), body mass index (p = 0.008), Barthel index (p < 0.001), method of anesthesia (p < 0.001), bone transplant (p = 0.010), timing of postoperative rehabilitation (p < 0.001), atrial fibrillation (p < 0.001), chronic pain (p < 0.001), and number of institutionally treated cases (p < 0.001) (r = 0.451, p < 0.001). CONCLUSIONS: Shorter or longer hospital stays were found to be associated with the patients' background characteristics and facility-specific factors; these can lead to more accurate estimates of the length of hospital stay and appropriate allocation of resources.

This study aimed to investigate the influence of certified perioperative nurses on preoperative outpatient clinic and preoperative assessments. The study was conducted from February 2021 to September 2022; data were collected and analyzed using a questionnaire at 247 hospitals in Japan. To analyze the factors affecting the rate of preoperative assessment with the primary endpoint of preoperative outpatient care and preoperative nursing visits, we performed multiple linear regression analysis of facility characteristics, perioperative nurse background, and the presence or absence of certified perioperative nurses. Regarding the presence or absence of a preoperative outpatient clinic, patients from 68 (52.3%) and 41 (35.0%) institutions in the enrolled and nonenrolled groups. Respectively, underwent a preoperative assessment; the rate of preoperative assessments in the enrolled group was significantly higher than that in the nonenrolled group. Multivariate analysis of factors influencing the preoperative assessment rate revealed a significant association with certified perioperative nurse attendance. Facilities with certified perioperative nurses have a significantly higher prevalence of preoperative outpatient clinic and significantly higher rates of preoperative assessments than facilities without certified perioperative nurses. Enrollment of certified perioperative nurses may lead to the improvement of the quality of preoperative nursing interventions.

Acute myocardial infarction (MI) is one of the major scenarios of extracorporeal membrane oxygenation (ECMO) use. The utilization of mechanical circulatory support systems including ECMO varies widely at the hospital level, while whether ECMO volume per hospital is associated with outcomes in acute MI is unclear. Using a Japanese nationwide administrative database, a total of 26,913 patients with acute MI undergoing percutaneous coronary intervention from 154 hospitals were included. The relations among PCI volume for acute MI, observed and predicted in-hospital mortality, and observed and predicted rates of ECMO use were evaluated at the hospital level. Of 26,913 patients, 423 (1.6%) were treated with ECMO, and 1561 (5.8%) died during the hospitalization. Median ECMO use per hospital per year was 0.5. An observed rate of ECMO use was linearly correlated with the predicted probability of ECMO use and was not associated with the observed/predicted in-hospital mortality ratio. The observed/predicted mortality ratio was lowest in hospitals with the observed/predicted ECMO use ratio of around one. In conclusion, ECMO was infrequently used in a setting of acute MI at each hospital annually. An observed rate of ECMO use was not associated with observed/predicted in-hospital mortality ratio, while the observed/predicted in-hospital mortality ratio was lowest when ECMO was used as predicted, suggesting that standardized ECMO use may be an institutional quality indicator in acute MI.

OBJECTIVES: We aimed to investigate the regional variations in the number of interventions and surgeries for peripheral artery disease (PAD) and explore the major determinants of the variations. DESIGN: Cross-sectional study. SETTING: The Japanese Ministry of Health, Labour and Welfare National Database and Diagnostic Procedure Combination database in 2018. DATA: The rates of endovascular treatment (EVT), bypass surgery per 100 000 individuals in the population were calculated for all 47 prefectures in Japan. The total annual changes in the rates of EVT and bypass surgery in Japan from 2012 to 2019 were calculated. ANALYSIS: A linear regression model was developed with rates of EVT and bypass surgery as dependent variables and regional medical supply in each prefecture as explanatory variables. These regional factors included the rate of percutaneous coronary intervention (PCI) for angina, the numbers of cardiovascular specialists, specialists in cardiac surgery, interventional radiology (IVR) training facilities and cardiovascular surgery training facilities, per 100 000, respectively. RESULTS: There was a 5.7-fold difference (143 and 25 per 100 000 individuals aged ≥40 years) in the highest and lowest EVT rates. The highest and lowest rates of bypass surgery were 34 and <10 per 100 000 individuals aged ≥40 years in a prefecture, respectively. The rate of PCI contributed most significantly positive to the rate of EVT (p<0.001). However, the numbers of IVR and cardiovascular surgery training facilities had significant positive and negative relationships, respectively, with the rate of EVT. The numbers of specialists in cardiac surgery and cardiovascular specialists had significant positive (p=0.01) and negative (p=0.01) correlations, respectively, with the rate of bypass surgery. CONCLUSIONS: Considerable regional variations in the rates of revascularisation for PAD were found. Unbalanced presence of medical resources, preference of suppliers and the training system had larger effects on the regional variation in Japan.

BACKGROUND/OBJECTIVE: Few reports have directly compared the outcomes of patients with acute ischemic stroke (AIS) who are managed in a stroke care unit (SCU) with those who are managed in an intensive care units (ICU). This large database study in Japan aimed to compare in-hospital mortality between patients with AIS admitted into SCU and those admitted into ICU. METHODS: Patients with AIS who were admitted between April 1, 2014, and March 31, 2019, were selected from the administrative database and divided into the SCU and ICU groups. We calculated the propensity score to match groups for which the admission unit assignment was independent of confounding factors, including the modified Rankin scale (mRS) score. The primary outcome was in-hospital mortality, and secondary outcomes were the mRS score at discharge, length of stay (LOS), and total hospitalization cost. RESULTS: Overall, 8,683 patients were included, and 960 pairs were matched. After matching, the in-hospital mortality rates of the SCU and ICU groups were not significantly different (5.9% vs. 7.9%, P = 0.106). LOS was significantly shorter (SCU = 20.9 vs. ICU = 26.2 days, P < 0.001) and expenses were significantly lower in the SCU group than in the ICU group (SCU = 1,686,588 vs. ICU = 1,998,260 yen, P < 0.001). mRS scores (score of 1-3 or 4-6) at discharge were not significantly different after matching. Stratified analysis showed that the in-hospital mortality rate was lower in the ICU group than in the SCU group among patients who underwent thrombectomy. CONCLUSIONS: In-hospital mortality was not significantly different between the ICU and SCU groups, with significantly lower costs and shorter LOS in the SCU group than in the ICU group.

Background Lower primary percutaneous coronary intervention (PCI) volume is known to be associated with worse outcomes in patients with acute myocardial infarction (MI) at hospital level. The present study aimed to evaluate the relations of primary, elective, and total PCI volume and primary/total PCI volume ratio per hospital to in-hospital mortality in patients with acute MI undergoing primary PCI. Methods and Results Using a large nationwide administrative database, we included a total of 83 076 patients from 154 hospitals in Japan undergoing PCI for either acute MI or elective cases. Relations of annual procedural volumes for primary, elective, and total PCI to in-hospital mortality after acute MI at hospital level were evaluated. The ratio of primary to total PCI volume per hospital was also assessed. The primary end point was the ratio of observed to predicted mortality. Of 83 076 patients, 26 913 (32.4%) underwent primary PCI for acute MI, among whom 1561 (5.8%) died during hospitalization. Overall, observed in-hospital mortality after acute MI and observed/predicted mortality ratio were higher in hospitals with lower primary, elective, and total PCI volumes. Observed/predicted in-hospital mortality ratio was higher in hospitals with low primary/total PCI volume ratio, even in those with high total PCI volume. Conclusions Primary, elective, and total PCI volume at hospitals were inversely associated with in-hospital mortality in patients with acute MI undergoing primary PCI. Lower ratio of primary to total PCI volume were related to higher in-hospital mortality, suggesting primary/total PCI volume ratio as an institutional indicator of quality of care for acute MI.

BACKGROUND: Triple antithrombotic therapy, including dual antiplatelet therapy and oral anticoagulant (OAC), is recommended for a short-term period after percutaneous coronary intervention (PCI) in patients requiring anticoagulation therapy. The purpose of this study was to compare in-hospital clinical outcomes between low-dose prasugrel (3.75 mg/day) and clopidogrel, as part of triple antithrombotic therapy, using a large database in Japan. METHODS: Patients with ischemic heart disease who underwent PCI between January 2015 and December 2019, and were prescribed triple therapy with aspirin, a P2Y12 inhibitor (clopidogrel or low-dose prasugrel), and OAC (direct oral anticoagulant: DOAC or vitamin K antagonist: VKA), were selected from the Diagnosis Procedure Combination database. The primary outcome was in-hospital mortality. The secondary outcomes were myocardial infarction, ischemic stroke, bleeding stroke, gastrointestinal bleeding, and blood transfusion. RESULTS: Overall, 5,777 patients were eligible in this analysis. The patients were divided into 4 subgroups according to the type of P2Y12 inhibitor and OAC: clopidogrel/DOAC (n = 1,628), clopidogrel/VKA (n = 1,334), prasugrel/DOAC (n = 1,607), and prasugrel/VKA (n = 1,208). There was no significant difference in the incidence of death and gastrointestinal bleeding among the 4 subgroups. The prasugrel/DOAC group had significantly lower incidence of MI (OR 0.566, 95% CI 0.348-0.921). The incidence of ischemic stroke was significantly lower in the prasugrel/DOAC group (OR 0.701, 95% CI 0.502-0.979), and significantly higher in the clopidogrel/VKA group (OR 1.680, 95% CI 1.273-2.216). Need for blood transfusion was less frequent in the prasugrel/DOAC group (OR 0.729, 95% CI 0.598-0.890), and more frequent in both the clopidogrel/VKA group (OR 1.424, 95% CI 1.187-1.708) and the prasugrel/VKA group (OR 1.633, 95% CI 1.367-1.950). CONCLUSIONS: Combination of low-dose prasugrel and DOAC was associated with lower incidence of MI, ischemic stroke, and blood transfusion. Low-dose prasugrel may be feasible as part of triple therapy in patients undergoing PCI.

Background: Regional variation in the use of percutaneous coronary intervention (PCI), especially when performed as an elective procedure, was observed in a previous study. The use of a developing technology, catheter ablation (CA), was compared between regions in Japan. Methods and Results: The Diagnostic Procedure Combination data, which are publicly available, were used for the analysis. The number of CAs was summarized and the rates for CA and PCI were calculated based on the prefecture's population aged ≥40 years. A linear regression model was constructed to identify the factors associated with regional variation in the use of CA. The number of CAs performed per hospital consistently increased from 2009 to 2018. The mean rate of CA across Japan was 119 per 100 000 population aged ≥40 years in 2018. The highest CA rate was 166 per 100 000 and the lowest CA rate was 29 per 100 000 in 2018, while the highest and lowest PCI rates for angina per 100 000 were 361 and 88 in 2018, respectively. The significant factor associated with regional variation in the CA rate was the number of specialists. Conclusions: A wide regional variation was observed in the use of CA for patients with arrhythmia in Japan. Further research is needed to generate evidence of CA for decision-making as a treatment option and to appropriately deploy this health service regardless of where patients live.

The management of acute decompensated heart failure often requires intensive care. However, the effects of early intensive care unit/coronary care unit admission on activities of daily living (ADL) in acute decompensated heart failure patients have not been precisely evaluated. Thus, we retrospectively assessed the association between early intensive care unit admission and post-discharge ADL performance in these patients. Acute decompensated heart failure patients (New York Heart Association I-III) admitted on emergency between April 1, 2014, and December 31, 2018, were selected from the Diagnosis Procedure Combination database and divided into intensive care unit/coronary care unit (ICU) and general ward (GW) groups according to the hospitalization type on admission day 1. The propensity score was calculated to create matched cohorts where admission style (intensive care unit/coronary care unit admission) was independent of measured baseline confounding factors, including ADL at admission. The primary outcome was ADL performance level at discharge (post-ADL) defined according to the Barthel index. Secondary outcomes included length of stay and total hospitalization cost (expense). Overall, 12231 patients were eligible, and propensity score matching created 2985 pairs. After matching, post-ADL was significantly higher in the ICU group than in the GW group [mean (standard deviation), GW vs. ICU: 71.5 (35.3) vs. 78.2 (31.2) points, P<0.001; mean difference: 6.7 (95% confidence interval, 5.1-8.4) points]. After matching, length of stay was significantly shorter and expenses were significantly higher in the ICU group than in the GW group. Stratified analysis showed that the patients with low ADL at admission (Barthel index score <60) were the most benefited from early intensive care unit/coronary care unit admission. Thus, early intensive care unit/coronary care unit admission was associated with improved post-ADL in patients with emergency acute decompensated heart failure admission.

BACKGROUND: Although current guidelines recommend admission to the intensive/coronary care unit (ICU/CCU) for patients with ST-segment elevation myocardial infarction (MI), routine use of the CCU in uncomplicated patients with acute MI remains controversial. We aimed to evaluate the safety of management in the general ward (GW) of hemodynamically stable patients with acute MI after primary percutaneous coronary intervention (PCI). METHODS: Using a large nationwide administrative database, a cohort of 19426 patients diagnosed with acute MI in 52 hospitals where a CCU was available were retrospectively analyzed. Patients with mechanical cardiac support and Killip classification 4, and those without primary PCI on admission were excluded. A total of 5736 patients were included and divided into the CCU (n = 3488) and GW (n = 2248) groups according to the type of hospitalization room after primary PCI. Propensity score matching was performed, and 1644 pairs were matched. The primary endpoint was in-hospital mortality at 30 days. RESULTS: The CCU group had a higher rate of Killip classification 3 and ambulance use than the GW group. There was no significant difference in the incidence of in-hospital mortality within 30 days among the matched subjects. Multivariable Cox proportional hazard model analysis among unmatched patients supported the findings (hazard ratio 1.12, 95% confidence interval 0.66-1.91, p = 0.67). CONCLUSIONS: The use of the GW was not associated with higher in-hospital mortality in hemodynamically stable patients with acute MI after primary PCI. It may be feasible for the selected patients to be directly admitted to the GW after primary PCI.

BACKGROUND: Regional variations in health-care delivery, processes and spending have been reported across the world. Differences in revascularization procedures have been observed in the USA and Canada, but little is known about regional variation in revascularization procedures in Japan.Methods and Results:Diagnostic procedure combination summary tables for 2013 issued by the Japanese government were used. The rates of percutaneous coronary intervention (PCI) per 100,000 population aged ≥40 years in each prefecture were summarized by angina and myocardial infarction (MI). Linear regression analysis was performed to investigate the factors associated with regional variation in the rate of PCI for angina. The mean PCI rates were 189 and 67 per 100,000 population for angina and MI, respectively. The ratios between the highest and lowest regions were 4.9-fold in angina and 1.8-fold in MI. The factor most associated with generating regional variation in the use of PCI for angina was the rate of coronary angiography (CAG; P<0.001). CONCLUSIONS: Wide regional variation was observed in the use of PCI both for angina and for MI. The variation was larger for angina, in which PCI were mostly elective and positively associated with the use of CAG. Further research is needed to prevent overuse and underuse of PCI to ensure more appropriate health-care delivery and to control health-care expenditure.

BACKGROUND: The initial treatment of acute ischemic stroke critically affects patient outcome. Patient outcome may also be associated with the day of hospital admission due to differences in the number of the hospital staff between weekdays and weekends. We aimed to assess the effect of weekend admission on in-hospital mortality among patients with ischemic stroke in Japan. METHODS: We analyzed patients with ischemic stroke from a large nationwide administrative dataset. The patients were grouped according to the treatment ward to which they were initially admitted: a general medical ward (GMW) or an intensive or stroke care unit (S-ICU). The primary outcome, in-hospital mortality, was compared between the patients admitted on a weekday versus weekend according to the initial treatment ward. A generalized estimated equation was applied for multivariate analysis. RESULTS: In total, 47,885 patients were included in the study. Of these patients, 32.0% were admitted to an S-ICU and 27.8% were admitted to a GMW on a weekend. The estimated in-hospital mortality rate was significantly higher among the patients admitted to a GMW on a weekend compared with those admitted on a weekday (7.9% versus 7.0%), but this difference was not significant after adjusting for the patients' background characteristics. The estimated in-hospital mortality rates of the patients admitted to an S-ICU were similar between weekend and weekday admissions (10.0% versus 9.9%). CONCLUSIONS: No significant effect of weekend admission in-hospital mortality was observed in our study population regardless of the initial treatment ward.

BACKGROUND AND PURPOSE: The Japanese stroke guideline recommends the use of stroke care units (SCUs) for acute stroke treatment, but few SCUs have been established and the evidence supporting their use is limited. The aim of this study was to evaluate the efficacy of SCUs compared with general medical wards (GMWs). METHODS: A multicenter observational study was conducted using a large administrative database involving 52 hospitals; patients with either intracerebral hemorrhage or cerebral infarction were included. In-hospital mortality was the primary end point, and this parameter as well as the proportion of patients with a modified Rankin Scale score of ≤2 at discharge were compared between patients who were treated at SCUs and GMWs. Propensity score matching was performed to correct for selection bias. RESULTS: A total of 6977 patients were identified, of which 4527 patients were admitted to SCUs and 2450 patients were admitted to GMWs. The in-hospital mortality of patients with intracerebral hemorrhage was 14.8% and 24.1% in SCUs and GMWs, respectively (P=0.0004); the mortality of patients with cerebral infarction was 3.6% and 5.7%, respectively (P=0.003). Multivariate analysis in propensity score-matched pairs indicated significantly lower risk of death in the SCU group among patients with both intracerebral hemorrhage (odds ratio, 0.36; P=0.0007) and cerebral infarction (odds ratio, 0.60; P=0.02). However, the proportions of patients with a modified Rankin Scale score of ≤2 were not significantly different between SCUs and GMWs. CONCLUSIONS: SCUs were associated with a reduced risk of in-hospital mortality of stroke patients compared with GMWs alone.