Oral anticoagulation after atrial fibrillation catheter ablation: benefits and risks.

BACKGROUND AND AIMS: Few recent large-scale studies have evaluated the risks and benefits of continuing oral anticoagulant (OAC) therapy after catheter ablation (CA) for atrial fibrillation (AF). This study evaluated the status of continuation of OAC therapy and the association between continuation of OAC therapy and thromboembolic and bleeding events according to the CHADS2 score. METHODS: This retrospective study included data from the Japanese nationwide administrative claims database of patients who underwent CA for AF between April 2014 and March 2021. Patients without AF recurrence assessed by administrative data of the treatment modalities were divided into two groups according to continuation of OAC therapy 6 months after the index CA. The primary outcomes were thromboembolism and major bleeding after a landmark period of 6 months. After inverse probability of treatment weighting analysis, the association between OAC continuation and outcomes was determined according to the CHADS2 score. RESULTS: Among 231 374 patients included, 69.7%, 21.6%, and 8.7% had CHADS2 scores of ≤1, 2, and ≥3, respectively. Of these, 71% continued OAC therapy at 6 months. The OAC continuation rate was higher in the high CHADS2 score group than that in the low CHADS2 score group. Among all patients, 2451 patients (0.55 per 100 person-years) had thromboembolism and 2367 (0.53 per 100 person-years) had major bleeding. In the CHADS2 score ≤1 group, the hazard ratio of the continued OAC group was 0.86 [95% confidence interval (CI): 0.74-1.01, P = .06] for thromboembolism and was 1.51 (95% CI: 1.27-1.80, P < .001) for major bleeding. In the CHADS2 score ≥3 group, the hazard ratio of the continued OAC group was 0.61 (95% CI: 0.46-0.82, P = .001) for thromboembolism and was 1.05 (95% CI: 0.71-1.56, P = 0.81) for major bleeding. CONCLUSIONS: This observational study suggests that the benefits and risks of continuing OAC therapy after CA for AF differ based on the patient's CHADS2 score. The risk of major bleeding due to OAC continuation seems to outweigh the risk reduction of thromboembolism in patients with lower thromboembolic risk.

Multisystemic Inflammation Influences Prognosis in Fulminant Lymphocytic Myocarditis.

BACKGROUND: Multisystem inflammatory syndrome (MIS) is a hyperinflammatory shock associated with cardiac dysfunction and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, there are no reports on using MIS criteria, such as multisystemic inflammation (MSI) in fulminant myocarditis, without SARS-CoV-2 infection. This study investigated the differences in clinical characteristics and course between patients with fulminant lymphocytic myocarditis (FLM) plus MSI and those without MSI. METHODS AND RESULTS: This multicenter retrospective cohort study included 273 patients with FLM registered in the JROAD-DPC database between April 2014 and March 2017. We evaluated the presence of MSI using criteria modified from previously reported MIS criteria and compared the characteristics and risk of mortality or heart transplantation between FLM patients with MSI and without MSI. Of the 273 patients with FLM, 107 (39%) were diagnosed with MSI. The MSI group was younger (44 vs. 57 years; P<0.0001) and had more females (50% vs. 36%; P=0.0236), a higher incidence of pericardial effusion (58% vs. 40%; P=0.0073), and a lower 90-day mortality rate (19% vs. 33%; P=0.0185) than the non-MSI group. The risk of mortality at 90 days was lower in FLM patients aged <50 years with MSI aged <50 years than in those without MSI (P=0.0463). CONCLUSIONS: These results suggest that MSI may influence the prognosis of FLM, especially in patients aged <50 years.

Uptitration of Sacubitril/Valsartan and Outcomes in Patients With Heart Failure　- Insight From the REVIEW-HF Registry.

BACKGROUND: Guideline-directed medical therapy has become an important component of heart failure (HF) therapy, with sacubitril/valsartan as one of the recommended drugs; however, the real-world prognostic implications of sacubitril/valsartan uptitration are unclear. METHODS AND RESULTS: Patients with HF newly initiated on sacubitril/valsartan were registered in a retrospective multicenter study (REVIEW-HF). In all, 995 patients were divided into 3 groups according to the maximum dose achieved: high dose, sacubitril/valsartan 400 mg; intermediate dose, sacubitril/valsartan 200-<400 mg; and low dose, sacubitril/valsartan <200 mg. A total of 397 (39.9%) patients received high-dose sacubitril/valsartan; they had a significantly lower risk of mortality or HF hospitalization than patients in the low-dose (hazard ratio [HR] 0.39; 95% confidence interval [CI] 0.29-0.53; P<0.001) and intermediate-dose (HR 0.64; 95% CI 0.45-0.94; P=0.03) groups. In the multivariable Cox regression model, higher systolic blood pressure and maintained geriatric nutritional risk index were significantly associated with a higher incidence of achieving a high dose of sacubitril/valsartan. Patients who did not receive high-dose sacubitril/valsartan experienced more hypotension during the follow-up period, whereas hyperkalemia, severe renal events, and angioedema did not differ across the achieved dose classifications. CONCLUSIONS: Patients who achieved sacubitril/valsartan uptitration had a better prognosis than those who did not. Before sacubitril/valsartan uptitration, patients need to monitor blood pressure closely to prevent worsening events.

Features and Outcomes of Histologically Proven Myocarditis With Fulminant Presentation.

BACKGROUND: Fulminant myocarditis presentation (FMP) is a rare and severe presentation of myocarditis. The natural history of FMP and its clinical features associated with poor outcomes are incompletely understood because there is a lack of generalizable evidence. METHODS: This multicenter retrospective cohort study included patients hospitalized with histologically proven myocarditis who underwent catecholamine or mechanical support from 235 cardiovascular training hospitals across Japan between April 2012 and March 2017. Clinical features and the prognostic predictors of death or heart transplantation within 90 days on the basis of clinical and pathologic findings were determined using the Kaplan-Meier method, log-rank test, and Cox regression analysis. RESULTS: This study included 344 patients with histologically proven FMP (median age, 54 years; 40% female). The median follow-up was 600 days (interquartile range, 36 to 1599 days) and the cumulative risk of death or heart transplantation at 90 days was 29% (n=98). Results from multivariable Cox regression analysis showed that older age, nonsinus rhythm, low left ventricular wall motion (<40%) on admission, and ventricular tachycardia or fibrillation on admission day were associated with worse 90-day survival. Severe histologic damage (damaged cardiomyocytes comprising ≥50% of the total cardiomyocytes) was associated with a worse 90-day prognosis in patients with lymphocytic myocarditis. CONCLUSIONS: The results from analyses of data from this multicenter registry demonstrated that patients with FMP are at a higher risk of death or heart transplantation in real-world settings. These observations inform which clinical and pathologic findings may be useful for prognostication in FMP. REGISTRATION: URL: https://www.umin.ac.jp/ctr; Unique identifier: UMIN000039763.

Management and Outcomes of Acute Heart Failure Hospitalizations in Japan.

BACKGROUND: Heart failure (HF) is a global burden on healthcare systems, but the literature regarding nationwide trends in the care and outcomes of HF hospitalization in Japan is limited. Therefore, we aimed to investigate the trends in patient characteristics, treatment patterns, and outcomes of patients hospitalized with acute HF.Methods and Results: We used data from the Japanese Registry of All Cardiac and Vascular Diseases and the Diagnosis Procedure Combination database between April 2012 and March 2021 to analyze 840,357 patients aged ≥18 years who were hospitalized with an acute HF diagnosis. Over the study period (2012-2020), the mean (±standard deviation) age increased from 78.9 (±11.9) years to 80.9 (±11.8) years (P for trend <0.001), the proportion of female patients decreased from 48.7% to 47.5% (P for trend=0.02), crude in-hospital mortality rate decreased from 11.5% to 10.9%, and 30-day HF readmissions decreased from 7.4% to 7.0% (both P for trend <0.001). The reduction in outcomes was more apparent in the older age groups. The standardized outcomes demonstrated the same trends as the crude outcomes. CONCLUSIONS: Our nationwide hospital admission analysis clarified that patients hospitalized with acute HF were getting older, but mortality and readmission rates also decreased, especially in older patients during the 2010s.

Validity of Diagnostic Algorithms for Cardiovascular Diseases in Japanese Health Insurance Claims.

BACKGROUND: We aimed to validate a claims-based diagnostic algorithm to identify hospitalized patients with acute major cardiovascular diseases (CVDs) from health insurance claims in Japan.Methods and Results: This retrospective multicenter validation study was conducted at 4 institutes, including Japanese Circulation Society-certified and uncertified hospitals in Japan. Data on patients with CVDs in departmental lists or with International Classification of Diseases, 10th Revision (ICD-10) codes for CVDs hospitalized between April 2018 and March 2019 were extracted. We examined the sensitivity and positive predictive value of a diagnostic algorithm using ICD-10 codes, medical examinations, and treatments for acute coronary syndrome (ACS), acute heart failure (HF), and acute aortic disease (AAD). We identified 409 patients with ACS (mean age 70.6 years; 24.7% female), 615 patients with acute HF (mean age 77.3 years; 46.2% female), and 122 patients with AAD (mean age 73.4 years; 36.1% female). The respective sensitivity and positive predictive value for the algorithm were 0.86 (95% confidence interval [CI] 0.82-0.89) and 0.95 (95% CI 0.92-0.97) for ACS; 0.74 (95% CI 0.70-0.77) and 0.79 (95% CI 0.76-0.83) for acute HF; and 0.86 (95% CI 0.79-0.92) and 0.83 (95% CI 0.76-0.89) for AAD. CONCLUSIONS: The validity of the diagnostic algorithm for Japanese claims data was acceptable. Our results serve as a foundation for future studies on CVDs using nationwide administrative data.

Clinical Significance of Atrial Tachyarrhythmia Duration for Ventricular Arrhythmia in Patients With Cardiac Resynchronization Therapy.

BACKGROUND: Atrial tachyarrhythmias (ATAs) are reportedly associated with ventricular arrhythmias (VAs). However, little is known about the association between ATA duration and the risk of VA. We investigated the relationship between ATA duration and subsequent VA in patients with a cardiac resynchronization therapy defibrillator (CRT-D).Methods and Results: We investigated associations between the longest ATA duration during the first year after cardiac resynchronization therapy (CRT) implantation and VA and VA relevant to ATA (VAATA) in 160 CRT-D patients. ATAs occurred in 63 patients in the first year. During a median follow-up of 925 days from 1 year after CRT implantation, 40 patients experienced 483 VAs. Kaplan-Meier analysis showed a significantly higher risk of VA in patients with than without ATA in the first year (log rank P=0.0057). Hazard ratios (HR) of VA (HR 2.36, 2.10, and 3.04 for ATA >30s, >6 min and >24 h, respectively) and only VAATA (HR 4.50, 5.59, and 11.79 for ATA >30s, >6 min and >24 h, respectively) increased according to the duration of ATA. In multivariate analysis, ATA >24 h was an independent predictor of subsequent VA (HR 2.42; P=0.02). CONCLUSIONS: Patients with ATA >24 h in the first year after CRT had a higher risk of subsequent VA and VAATA. The risk of VA, including VAATA, increased with the longest ATA duration.

Temporal Trends and Regional Variations in Cardiovascular Care in Japan, 2010-2019.

Cardiovascular diseases are a major cause of mortality worldwide. Nonetheless, the current trend in cardiology hospitals in Japan has not been comprehensively explored.This descriptive study used the Japanese Registry of All Cardiac and Vascular Diseases database during 2010-2019. The nationwide 10-year trend in cardiovascular medical care systems was described in detail corresponding to the regions in Japan.Cardiovascular facilities and the number of cardiology beds, hospitalized patients, and cardiologists increased during 2010-2019. There were regional differences in the number of patients and cardiologists per bed, but the differences in the number of hospitalized patients per cardiologist decreased among the regions. Of the three major acute cardiovascular diseases, patients hospitalized with heart failure per cardiologist have been increasing. However, the in-hospital mortality rates have not changed over the last decade (8.6% for acute myocardial infarction, 7.7% for heart failure, and 12.7% for acute aortic dissection in 2019).There was an increasing trend in the availability of cardiovascular care resources in Japan during 2010-2019. This study provides a comprehensive summary of the current cardiovascular care and the follow-up required in the future.

The impact of hospital case volume on the outcomes after catheter ablation for atrial fibrillation according to the ablation technology.

INTRODUCTION: The appropriate hospital case volume for catheter ablation (CA) in patients with atrial fibrillation (AF) according to the ablation technology has not been fully examined. This study aimed to investigate the association between the hospital case volume for AF and periprocedural complications and AF recurrence. METHODS: In this retrospective cohort study, we used data from the National Database of Health Insurance Claims and Specific Health Checkups, which covers almost all healthcare insurance claims data in Japan. We included patients with AF who underwent first-time CA from April 2014 to March 2020. Using mixed-effect logistic regression, we analyzed the effect of the annual case volume for AF ablation on acute periprocedural complications and 1-year success rate off antiarrhythmic drugs according to the ablation technology (radiofrequency ablation or cryoballoon ablation). RESULTS: Among 270 116 patients, 207 839 (77%) patients underwent radiofrequency ablation and 56 648 (21%) patients underwent cryoballoon ablation. Of all patients, acute complications occurred in 5411 (2.0%) patients, and the recurrence at 1 year was 71 511 (27%). In the radiofrequency ablation group, acute complications and 1-year AF recurrence according to case volume decreased as the annual case volume increased to up to 150-200 cases/year. However, in the cryoballoon ablation group, these outcomes were similar regardless of the case volumes. CONCLUSION: The case-volume effect was noted in the radiofrequency ablation group, but not in the cryoballoon ablation group. Our results may affect the selection of ablation technology, especially in smaller case-volume hospitals.

Contemporary use of SGLT2 inhibitors in heart failure patients with diabetes mellitus: a comparison of DPP4 inhibitors in a nationwide electric health database of the superaged society.

BACKGROUND: There is a lack of recent data reflecting the actual use of sodium-glucose cotransporter-2 (SGLT2) inhibitors for heart failure (HF) and type 2 diabetes (DM) in the superaged society. The present study investigated the association between the use of SGLT2 inhibitors and one-year prognosis in patients hospitalized across a broad spectrum of HF patients with DM in the superaged society using the Nationwide Electric Health Database in Japan. METHODS: The patients hospitalized with the first episode of acute HF were identified from the National Database of Health Insurance Claims and Specific Health Checkups of Japan between April 2014 and March 2019. A cohort of 2,277 users of SGLT2 inhibitors and 41,410 users of the active comparator, dipeptidyl peptidase-4 (DPP4) inhibitors were compared. A propensity score-matched cohort study of 2,101 users of each inhibitor was also conducted. A multivariable multilevel mixed-effects survival model was conducted with adjustments, and hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. RESULTS: Among 300,398 patients discharged with HF in 4,176 hospitals, 216,016 (71.9%) were 75 years or older, and 60,999 (20.3%) took antidiabetic medications. Among them, the patients treated with SGLT2 inhibitors were younger and had a more severe status than those treated with DPP4 inhibitors. Kaplan-Meier analysis showed that patients treated with SGLT2 inhibitors had a lower mortality risk and HF readmission. In propensity-matched cohorts, SGLT2 inhibitor use was associated with a lower risk of mortality and HF readmission than DPP-4 inhibitor use (HR [95% CI]; 0.70 [0.56, 0.89] and 0.52 [0.45, 0.61], respectively). Very elderly (≥ 75 years) patients showed similar results. Favorable effects were also observed across all age groups, including ≥ 75 years, in patients with coronary artery disease or atrial fibrillation and with concomitant ß-blocker, diuretics, or insulin. CONCLUSION: The use of SGLT2 inhibitors at discharge was associated with a lower risk of one-year mortality and HF readmission in patients across a broad spectrum of HF with DM in the superaged society. The findings further support the benefits of using SGLT2 inhibitors in very elderly HF care and complement the current evidence.

Trends and Factors Associated With Cardiac Rehabilitation Participation　- Data From Japanese Nationwide Databases.

BACKGROUND: Few studies have comprehensively evaluated the trends and factors associated with CR participation across major cardiovascular diseases in Japan.Methods and Results: This study performed a nationwide cross-sectional study using the National Database of Health Insurance Claims and Specific Health Checkups of Japan and the Japanese Registry of All Cardiac and Vascular Diseases and the Diagnosis Procedure Combination database. This study described the nationwide trends and evaluated patient- and hospital-level associated factors of CR participation for patients with acute heart failure (AHF), acute coronary syndrome (ACS), acute aortic dissection (AAD), peripheral artery disease (PAD), and after cardiovascular surgery using mixed-effect logistic regression analysis. Although the annual number of patients who underwent CR has increased during the study period, the total number of patients participating in outpatient CR was lower than that of inpatient CR. The outpatient CR participation rate was lower for patients with AHF (3.5%), AAD (3.2%), and PAD (1.7%), compared with ACS (7.9%) and after surgery (9.4%). Age, sex, body mass index, Barthel index, Charlson comorbidity index, and institutional capacity were identified as significant associated factors of CR participation in inpatient and outpatient settings. CONCLUSIONS: Participation in outpatient CR was still low, and higher age, multi-comorbidity, and low institutional capacity contributed to the lower outpatient CR participation rate. Identification of the associated factors may help cardiologists to increase CR participation.

New Conversion Formula Between B-Type Natriuretic Peptide and N-Terminal-Pro-B-Type Natriuretic Peptide　- Analysis From a Multicenter Study.

BACKGROUND: Although B-type natriuretic peptide (BNP) and N-terminal (NT)-proBNP are commonly used markers of heart failure, a simple conversion formula between these peptides has not yet been developed for clinical use.Methods and Results: A total of 9,394 samples were obtained from Nara Medical University, Jichi Medical University, and Osaka University. We randomly selected 70% for a derivation set to investigate a conversion formula from BNP to NT-proBNP using estimated glomerular filtration rate (eGFR) and body mass index (BMI); the remaining 30% was used as the internal validation set and we used a cohort study from Nara Medical University as an external validation set. Multivariate linear regression analysis revealed a new conversion formula: log NT-proBNP = 1.21 + 1.03 × log BNP - 0.009 × BMI - 0.007 × eGFR (r2=0.900, P<0.0001). The correlation coefficients between the actual and converted values of log NT-proBNP in the internal and external validation sets were 0.942 (P<0.0001) and 0.891 (P<0.0001), respectively. We applied this formula to samples obtained from patients administered with sacubitril/valsartan. After treatment initiation, NT-proBNP levels decreased and actual BNP levels increased. However, the calculated BNP levels decreased roughly parallel to the NT-proBNP levels. CONCLUSIONS: This new and simple conversion formula of BNP and NT-proBNP with eGFR and BMI is potentially useful in clinical practice.

Catheter ablation of ganglionated plexi in patients with adenosine triphosphate-induced atrial fibrillation after pulmonary vein isolation.

Intravenous ATP may induce atrial fibrillation (AF). ATP shares similar receptor-effector coupling systems with acetylcholine. However, the association between an ATP injection and the hyperactivity of the intrinsic cardiac autonomic nervous system, known as ganglionated plexi (GPs), is not well understood. We describe a series of patients with non-pulmonary vein (PV) trigger sites provoked by an ATP injection, and assess the feasibility of a ganglionated plexus (GP) ablation. We retrospectively analyzed 547 patients (69% male; mean age 67.4 ± 10.4 years; 38.5% non-paroxysmal AF) who underwent a total of 604 ablation procedures. Intravenous ATP was administered with an isoproterenol infusion during sinus rhythm after a pulmonary vein isolation in 21.3%, Box isolation in 78.6%, and SVC isolation in 52.0% of the procedures, respectively. We reviewed the incidence, the distribution of the foci, and the ablation outcomes in patients with ATP-induced AF. A total of seven patients (1.3%) had ATP-induced AF. Foci were identified in the coronary sinus (CS) in six patients, right atrial posterior wall (RAPW) adjacent to the interatrial groove in two, mitral annulus in two, ligament of Marshall in one, right septum below the foramen ovale in one and left atrial posterior wall in one, respectively. Among these trigger foci, we confirmed the vagal response by high-frequency stimulation in the CS and RAPW in six and two patients, respectively. After a median RF time of 2.9 min (range 2.5-11.3) targeting these foci, in five of six patients who received a repeat ATP injection, the AF became non-inducible. ATP-provoked trigger foci were distributed among certain sites that overlapped with the distribution of the GPs. The GP ablation was effective for this rare, but challenging situation.

Quality indicators for acute cardiovascular diseases: a scoping review.

BACKGROUND: Although many quality indicator (QI) sets have been developed for acute cardiovascular diseases, a comprehensive summary is lacking. In this scoping review we aimed to summarize the available evidence on the QI sets for acute cardiovascular diseases, and assess the QI set development process. We followed the Joanna Briggs Institute framework and the PRISMA extension for scoping reviews. METHODS: We conducted a systematic search of MEDLINE, EMBASE, and major international guidelines on QIs for acute major cardiovascular diseases. The study included articles published after 2000. RESULTS: Among the 3112 articles screened, 18 were included in this scoping review. Among the 18 articles included, 12 were on acute coronary syndrome (ACS), five on acute heart failure (AHF), and two on acute aortic dissection (AAD); one article included QIs for both ACS and AHF. Only four of these studies conducted a systematic search with a search strategy. From the 18 articles, 268 QIs containing duplication between articles were identified (191 QIs were for ACS, 57 were for AHF, and 20 were for AAD) and QI measurements varied across articles. CONCLUSIONS: This scoping review provides a comprehensive list of QIs for acute cardiovascular diseases. Our results may be helpful to clinicians and organizations seeking to develop QIs for acute cardiovascular care in the future.

Hospitalization Costs for Patients With Acute Congestive Heart Failure in Japan.

BACKGROUND: With aging of the population, the economic burden associated with heart failure (HF) is expected to increase. However, little is known about the hospitalization costs associated with HF in Japan. Methods and Results: In this cross-sectional study, using data from The Japanese Registry of All Cardiac and Vascular Diseases (JROAD) and JROAD-Diagnosis Procedure Combination databases between 2012 and 2014, we evaluated hospitalization costs for acute cardiovascular diseases (CVDs), including HF. A total of $1,187 million/year (44% of the hospitalization costs for acute CVDs) was spent on patients with HF. We identified 273,865 patients with HF and the median cost per patient was $8,089 ($5,362-12,787) per episode. The top 1% of spenders accounted for 8% ($80 million/year), and the top 5% of spenders accounted for 22% ($229 million/year) of the entire cost associated with HF. The costs associated with HF for patients over 75 years of age accounted for 68% of the total cost. CONCLUSIONS: The costs associated with HF were higher than the hospitalization cost for any other acute CVD in Japan. Understanding how the total hospitalization cost is distributed may allow health providers to utilize limited resources more effectively for patients with HF.

Simple Risk Score to Predict Survival in Acute Decompensated Heart Failure　- A2B Score.

BACKGROUND: Prognosis after acute decompensated heart failure (ADHF) is poor. An appropriate risk score that would allow for improved care and treatment of ADHF patients after discharge, however, is lacking. Methods and Results: We used 2 HF cohorts, the NARA-HF study and JCARE-CARD, as derivation and validation cohorts, respectively. The primary endpoint was all-cause death during the 2-year follow-up, excluding in-hospital death. Age, hemoglobin (Hb), and brain natriuretic peptide (BNP) at discharge were identified as independent risk factors. We determined 3 categorizations on the basis of these parameters, termed A2B score: age (<65 years, 0; 65-74 years, 1; ≥75 years, 2), anemia (Hb <10 g/dL, 2; 10-11.9 g/dL, 1; ≥12 g/dL, 0) and BNP (<200 pg/mL, 0; 200-499 pg/mL, 1; ≥500 pg/mL, 2). We divided patients into 4 groups according to A2B score (extremely low, 0; low, 1-2; medium, 3-4; high, 5-6). For the extremely low-risk group, the 2-year survival rate was 97.8%, compared with 84.5%, 66.1%, and 45.2% for the low-, medium-, and high-risk groups, respectively. Using the JCARE-CARD as a validation model, for the extremely low-risk group, the 2-year survival was 95.4%, compared with 90.2%, 75.0%, and 55.6% for the low-, medium-, and high-risk groups, respectively. CONCLUSIONS: The user-friendly A2B score is useful for estimating survival rate in ADHF patients at discharge.

Number of Board-Certified Cardiologists and Acute Myocardial Infarction-Related Mortality in Japan　- JROAD and JROAD-DPC Registry Analysis.

BACKGROUND: The appropriate number of board-certified cardiologists (BCC) for the treatment of acute myocardial infarction (AMI) has not been thoroughly examined in Japan. This study investigated whether the number of BCC/50 cardiovascular beds affects acute outcome in AMI treatment. Methods and Results: Data on 751 board-certified teaching hospitals and 63,603 patients with AMI were obtained from the Japanese Registry Of All cardiac and vascular Diseases (JROAD) and JROAD Diagnosis Procedure Combination (JROAD-DPC) databases between 1 April 2012 and 31 March 2014. The hospitals were categorized into 3 groups based on the median number of BCC/50 cardiovascular beds: first tertile, 5.0 (IQR, 4.0-5.7); second, 8.3 (IQR, 7.4-9.8); third, 15.3 (IQR, 12.5-22.7), and the patients with AMI admitted to the categorized hospitals were compared (first tertile, 12,002 patients; second, 23,930; third, 27,671). On hierarchical logistic modeling, the adjusted OR for 30-day mortality were 0.86 (95% CI: 0.74-1.00) for the second tertile and 0.75 (95% CI: 0.65-0.88) for the third tertile. CONCLUSIONS: Patients with AMI admitted to hospitals with a large number of BCC/50 cardiovascular beds had a lower 30-day mortality rate. This tendency was independent of patient and hospital characteristics. This is the first study to provide new information on the association between the number of BCC and in-hospital AMI-related mortality in Japan.