Differences in the feasibility, anatomical parameters predicting procedural difficulty, and isolation area of a left atrial posterior wall isolation using radiofrequency versus cryoballoon catheters.

BACKGROUNDS: The difficulty and outcome of the adjunctive left atrial posterior wall isolation (LAPWI) in patients with persistent atrial fibrillation (PersAF) may be affected by the ablation energy used. This study aimed to compare the completion rate, anatomical parameters predicting procedural difficulty, and the isolation area of a LAPWI between the use of radiofrequency (RFA) and cryoballoon ablation (CBA). METHODS: We enrolled 95 and 93 patients with PersAF who underwent pulmonary vein isolation (PVI)+LAPWI using RFA (RF group) and CBA (CB group), respectively. Preoperative computed tomography was used to evaluate the anatomical features associated with an incomplete LAPWI. Post-ablation 3-dimensional maps were analyzed to quantify the isolation area. RESULTS: The completion rate of the LAPWI was significantly higher in the RF group than the CB group without touch-up RFA (88.4% vs. 72.0%; p = .005). Predictors of incomplete LAPWI were a longer left inferior pulmonary vein (LIPV)-esophageal distance (p < .001) for RFA and a steeper angle of the LAPW (p < .001) and longer transverse LAPW diameter (p = .016) for CBA. The isolated non-PV area with RFA or CBA alone was significantly greater in the CB group than the RF group (27.5 ± 9.5 cm2 vs. 22.9 ± 6.9 cm2 ; p < .001). CONCLUSION: The position of the esophagus at a distance from the LIPV was associated with an incomplete LAPWI using RFA, while a steeper angle of the LAPW and transverse enlargement of the LAPW were associated with that using CBA. The completion rate of the LAPWI was higher with RFA, but the isolation area outside of the PVs was greater with CBA.

Cardiovascular Risk Factors and Culprit Plaque Characteristics in Women With Acute Coronary Syndromes.

Outcomes after myocardial infarction in women remain poor. The number of cardiovascular risk factors in women increase with age, however the relation between risk factors and culprit plaque characteristics in this population is poorly understood. The aim of the study was to investigate the relation between risk factors and culprit plaque characteristics in women with acute coronary syndrome (ACS). A total of 382 women who presented with ACS and underwent pre-intervention optical coherence tomography imaging of the culprit lesion were included in this analysis. The culprit plaques were categorized as plaque rupture, plaque erosion or calcified plaque, and then stratified by age and risk factors. The predominant pathology of ACS was plaque erosion in young patients (<60 years), which decreased with age (p <0.001). Current smokers had a high prevalence of plaque rupture (60%) and lipid plaque (79%). Women with diabetes tended to have more lipid plaque (70%) even at a young age. In women with hyperlipidemia, the prevalence of lipid plaques was modest in younger ages, but rose gradually with age (p <0.001). An increasing age trend for lipid plaque was also observed in women with hypertension (p = 0.03) and current smokers (p = 0.01). In conclusion, early treatment of risk factors such as diabetes in young women might be important before accelerated progression of atherosclerosis begins as age advances. Clinical trial registration: http://www.clinicaltrials.gov, NCT01110538, NCT03479723 and NCT02041650.

Sex Differences in Coronary Atherosclerotic Phenotype and Healing Pattern on Optical Coherence Tomography Imaging.

BACKGROUND: Layered plaque, a signature of previous plaque disruption, is a known predictor of rapid plaque progression. Layered plaque can be identified in vivo by optical coherence tomography. Studies have reported differences in plaque burden between women and men, but sex differences in the pattern of layered plaque are unknown. METHODS: Preintervention optical coherence tomography images of 533 patients with chronic coronary syndromes were analyzed. Detailed plaque characteristics of layered and nonlayered plaques of the target lesion were compared between men and women. RESULTS: The prevalence of layered plaque was similar between men (N=418) and women (N=115; 55% versus 54%; P=0.832). In men, more features of plaque vulnerability were identified in layered plaque than in nonlayered plaque: lipid plaque (87% versus 69%; P<0.001), macrophages (69% versus 56%; P=0.007), microvessels (72% versus 39%; P<0.001), and cholesterol crystals (49% versus 30%; P<0.001). No difference in plaque vulnerability between layered and nonlayered plaques was observed in women. Layered plaque in men had more features consistent with previous plaque rupture than in women: interrupted pattern (74% versus 52%; P<0.001) and a greater layer index (1198 [781-1835] versus 943 [624-1477]; P<0.001). CONCLUSIONS: In men, layered plaques exhibit more features of vascular inflammation and vulnerability as well as evidence of previous plaque rupture, compared with nonlayered plaques, whereas in women, no difference was observed between layered and nonlayered plaques. Vascular inflammation (plaque rupture) may be the predominant mechanism of layered plaque in men, whereas a less inflammatory mechanism may play a key role in women. REGISTRATION: URL: http://www. CLINICALTRIALS: gov; Unique Identifier: NCT01110538, NCT04523194.

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.

Hospital- and Patient-Level Analysis of Quality Indicators in Acute Coronary Syndrome Care: A Nationwide Database Study.

BACKGROUND: This study aimed to clarify the variations in the quality of care provided to patients with acute coronary syndrome (ACS) and to investigate the association between quality of care and mortality at both hospital and patient levels with the use of a nationwide database. METHODS: Patients with ACS who underwent percutaneous coronary intervention (PCI) from April 2014 to March 2018 were included from the National Database of Health Insurance Claims and Specific Health Checkups of Japan. Twelve quality indicators (QIs) available from administrative data and the association of the QIs with all-cause mortality were investigated. RESULTS: From the analysis of 216,436 patients from 1215 hospitals, adherence to PCI on admission day, aspirin use on arrival, P2Y12 inhibitor use, and left ventricular function assessment were high (median proportion > 90%), and adherence to outpatient cardiac rehabilitation was low (median proportion < 10%). At the hospital level, acute-phase composite QI score was associated with reduced risk-adjusted 30-day mortality (ß = -0.92 [95% confidence interval -1.19 to -0.65]; P < 0.001). At the patient level, all acute-phase and subacute-phase QIs were inversely associated with 30-day and 2-year mortalities, respectively (all P < 0.001). CONCLUSIONS: Substantial variations in ACS care were observed in the current nationwide database. High adherence to the QI sets was associated with significant survival gains at both hospital and patient levels. Multilevel approach in QI assessment may be effective for improvement of survival in this population.

Clinical impact of beta-blockers at discharge on long-term clinical outcomes in patients with non-reduced ejection fraction after acute myocardial infarction.

BACKGROUND: Beta-blockers are associated with several clinical benefits in patients with reduced left ventricular ejection fraction (REF) after acute myocardial infarction (AMI), such as lower rates of mortality, recurrence of myocardial infarction, and heart failure. However, the long-term prognosis of beta-blockers has rarely been investigated in patients with non-REF after AMI. This study aimed to investigate the clinical benefits of beta-blockers in these patients. METHODS: A total of 3281 consecutive patients who were hospitalized within 48 h after AMI were registered in the J-MINUET study. Patients who underwent primary percutaneous coronary intervention (PCI) and had a left ventricular ejection fraction ≥40 % were enrolled, and patients who died during admission were excluded. Included patients were divided into two groups according to the prescription of beta-blockers at discharge. Their characteristics and clinical outcomes were compared. RESULTS: The number of AMI patients treated with beta-blockers was 1353 (70.4 %). Patients who received beta-blockers were younger and had a higher incidence of hypertension, dyslipidemia, and ST-segment elevation myocardial infarction than those who did not receive beta-blockers. The peak creatine kinase level after primary PCI was significantly higher in patients who received beta-blockers. These patients also had a lower incidence of a composite of all-cause death, myocardial infarction, and stroke compared to those that did not receive beta-blockers (7.3 % vs. 11.9 %, p = 0.001). Multivariate analysis showed that beta-blocker use was an independent factor for better clinical outcomes. CONCLUSIONS: The J-MINUET study revealed the clinical benefit of beta-blockers in AMI patients with non-REF after primary PCI.

Prediction of optical coherence tomography-detected calcified nodules using coronary computed tomography angiography.

Diagnosis of calcified nodules (CNs) is critical in the proper management of coronary artery disease, but CNs can be detected only using intracoronary imaging modalities. This study aimed to investigate the ability of coronary computed tomography angiography (CCTA) in predicting CNs detected using optical coherence tomography (OCT). From 138 patients who underwent OCT-guided percutaneous coronary intervention (PCI) after CCTA evaluation, 141 PCI target vessels were retrospectively enrolled and classified into CN (12 vessels/11 patients; CNs in the PCI culprit lesion) and non-CN (129 vessels/127 patients; without CNs) groups based on the OCT analysis. Retrospective CCTA analysis revealed significantly higher coronary artery calcification score (CACS), calcified plaque volume (CPV), and maximum calcified plaque area (MCPA) of the target vessel in the CN group than in the non-CN group. Receiver operating characteristic curve indicated that CACS ≥ 162 (area under the ROC curve (AUC 0.76, sensitivity 83.3%, specificity 54.2%), CPV ≥ 20.1 mm3 (AUC 0.83, sensitivity 100%, specificity 57.3%), and MCPA ≥ 4.51 mm2 (AUC 0.87, sensitivity 91.7%, specificity 78.3%) were the best cutoff values for predicting CNs. MCPA showed the highest AUC among all the CCTA parameters. In conclusion, CCTA is useful for predicting OCT-detected CNs in PCI target vessels.

Age-dependent association of discharge heart-failure medications with clinical outcomes in a super-aged society.

AIMS: Real-world evidence about heart failure (HF) medical care for elderly patients is limited. The aim of this study was to clarify the age-dependent associations of HF medications at discharge with clinical outcomes in a super-aged society using a real-world big database. METHODS AND RESULTS: Patients hospitalized with a first episode of acute HF in 2013-2019 were identified in a nationwide claims database in Japan and were analyzed based on the HF medications at discharge. Hazard ratios (HRs) and 95 % confidence intervals (95 % CIs) for clinical outcomes were calculated after adjustment. Among 325,468 patients from 4351 hospitals, 130,230 (40.0 %) were aged ≥ 85 years. All-cause mortality and HF readmission rate within 1 year were 14 % and 23 %, respectively. ß-Blockers and angiotensin-converting-enzyme inhibitors or angiotensin II receptor blockers (ACEI/ARB) uses were associated with lower mortality (HR [95 %CI]: 0.84 [0.83,0.86] and 0.73 [0.71,0.74], respectively) and HF readmission (0.98 [0.97,0.99] and 0.89 [0.88,0.90], respectively). The associations were attenuated as the age increased and, in ß-blockers use, the favorable associations with mortality and HF readmission were not observed in patients with ≥ 95 years and ≥ 80 years, respectively. In contrast, mineralocorticoid receptor antagonists (MRA) use was associated only with lower HF readmission (0.83 [0.82,0.84]), which was not attenuated with increased age. CONCLUSIONS: The favorable associations of ß-blockers and ACEI/ARB uses with mortality and HF readmission were age-dependently attenuated in patients across a broad spectrum of HF in a super-aged society. In contrast, positive impact of MRA use on HF readmission was not attenuated with aging.

Reverse Remodeling and Non-Contrast T1 Hypointense Infarct Core in Patients With Reperfused Acute Myocardial Infarction.

BACKGROUND: Non-contrast T1 hypointense infarct cores (ICs) within infarcted myocardium detected using cardiac magnetic resonance imaging (CMR) T1 mapping may help assess the severity of left ventricular (LV) injury. However, because the relationship of ICs with chronic LV reverse remodeling (LVRR) is unknown, this study aimed to clarify it.Methods and Results: We enrolled patients with reperfused AMI who underwent baseline CMR on day-7 post-primary percutaneous coronary intervention (n=109) and 12-month follow-up CMR (n=94). Correlations between ICs and chronic LVRR (end-systolic volume decrease ≥15% at 12-month follow-up from baseline CMR) were investigated. We detected 52 (47.7%) ICs on baseline CMR by non-contrast-T1 mapping. LVRR was found in 52.1% of patients with reperfused AMI at 12-month follow-up. Patients with ICs demonstrated higher peak creatine kinase levels, higher B-type natriuretic peptide levels at discharge, lower LV ejection fraction at discharge, and lower incidence of LVRR than those without ICs (26.5% vs. 73.3%, P<0.001) at follow-up. Multivariate logistic regression analysis showed that the presence of ICs was an independent and the strongest negative predictor for LVRR at 12-month follow-up (hazard ratio: 0.087, 95% confidence interval: 0.017-0.459, P=0.004). Peak creatine kinase levels, native T1 values at myocardial edema, and myocardial salvaged indices also correlated with ICs. CONCLUSIONS: ICs detected by non-contrast-T1 mapping with 3.0-T CMR were an independent negative predictor of LVRR in patients with reperfused AMI.

Automated diagnosis of optical coherence tomography imaging on plaque vulnerability and its relation to clinical outcomes in coronary artery disease.

This study sought to develop a deep learning-based diagnostic algorithm for plaque vulnerability by analyzing intravascular optical coherence tomography (OCT) images and to investigate the relation between AI-plaque vulnerability and clinical outcomes in patients with coronary artery disease (CAD). A total of 1791 study patients who underwent OCT examinations were recruited from a multicenter clinical database, and the OCT images were first labeled as either normal, a stable plaque, or a vulnerable plaque by expert cardiologists. A DenseNet-121-based deep learning algorithm for plaque characterization was developed by training with 44,947 prelabeled OCT images, and demonstrated excellent differentiation among normal, stable plaques, and vulnerable plaques. Patients who were diagnosed with vulnerable plaques by the algorithm had a significantly higher rate of both events from the OCT-observed segments and clinical events than the patients with normal and stable plaque (log-rank p < 0.001). On the multivariate logistic regression analyses, the OCT diagnosis of a vulnerable plaque by the algorithm was independently associated with both types of events (p = 0.047 and p < 0.001, respectively). The AI analysis of intracoronary OCT imaging can assist cardiologists in diagnosing plaque vulnerability and identifying CAD patients with a high probability of occurrence of future clinical events.

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.

Sex Differences in Culprit Plaque Characteristics Among Different Age Groups in Patients With Acute Coronary Syndromes.

BACKGROUND: Despite the significant decline in cardiovascular mortality in women over the past several decades, sex differences in the underlying pathology of acute coronary syndromes remain poorly understood. Previous postmortem studies have demonstrated sex differences in coronary plaque morphology with a higher prevalence of plaque erosion in young women and more plaque rupture in older women after menopause, whereas men showed no increase in prevalence of plaque rupture with age. However, in vivo data are limited. METHODS: This study included patients who presented with acute coronary syndrome and underwent preintervention optical coherence tomography imaging of the culprit lesion. The culprit plaque was categorized as plaque rupture, plaque erosion or culprit plaque with calcification, and stratified by age. Features of plaque vulnerability at culprit lesion were also analyzed. RESULTS: In 1368 patients (women=286), women and men had a similar distribution of culprit plaque morphology (plaque rupture versus plaque erosion). However, significant sex differences were found in the underlying mechanisms of acute coronary syndrome among different age groups: women showed a significant ascending trend with age in plaque rupture (P<0.001) and the features of plaque vulnerability such as lipid plaque (P<0.001), thin-cap fibroatheroma (P=0.005), and microstructures including macrophages, cholesterol crystals, and calcification (P=0.026). No trend was observed in men. CONCLUSIONS: Age related sex differences in culprit plaque morphology and vulnerability were identified in patients with acute coronary syndrome: prevalence of plaque rupture and vulnerability increased with age in women but not in men. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01110538 and NCT03479723.

Incidence and prognostic impact of the calcified nodule in coronary artery disease patients with end-stage renal disease on dialysis.

Coronary artery calcification is frequently observed in coronary artery disease (CAD) patients with end-stage renal disease (ESRD). Calcified nodule (CN) is recognized as one of the vulnerable plaque characteristics responsible for acute coronary syndrome (ACS). Although CN is a cause of ACS in only 10%, its prevalence may be higher in elderly patients and/or ESRD. The aim of this study is to investigate incidence, clinical characteristics, and prognostic impact of CN in CAD patients with ESRD on dialysis. A total of 51 vessels from 49 CAD patients with ESRD on dialysis were enrolled in this study. CN was defined as a high-backscattering mass protruding into the lumen with a strong signal attenuation and an irregular surface by optical coherence tomography. Incidence, clinical characteristics and prognosis of patients with CN were studied. Major adverse cardiac events (MACE) were defined as a composite of all-cause death, non-fatal myocardial infarction, target vessel revascularization (TVR) and stroke. CNs were observed in 30 vessels from 29 patients (59.2%). Duration of dialysis was significantly longer in CN group than in non-CN group (P = 0.03). Overall, all-cause death, cardiac death, TVR and MACE occurred in 7 (14.3%), 3 (6.1%), 11 (22.4%) and 16 (32.7%) patients during follow-up (median 826 days), respectively. Kaplan-Meier survival analysis revealed that MACE-free survival was significantly lower in patients with CN compared with those without CN (Log-rank, P = 0.036).In conclusion, CN was observed in about 60% of the CAD patients with ESRD and was associated with duration of dialysis and worse prognosis.

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.

Prevention of Contrast-Induced Nephropathy After Cardiovascular Catheterization and Intervention With High-Dose Strong Statin Therapy in Japan　- The PREVENT CINC-J Study.

BACKGROUND: Previous studies have reported that high-dose strong statin therapy reduces the incidence of contrast-induced nephropathy (CIN) in statin naïve patients; however, the efficacy of high-dose strong statins for preventing CIN in real-world clinical practice remains unclear. The aim of this study was to evaluate the efficacy of strong statin therapy in addition to fluid hydration for preventing CIN after cardiovascular catheterization.Methods and Results: This prospective, multicenter, randomized controlled trial included 420 patients with chronic kidney disease who underwent cardiovascular catheterization. They were assigned to receive high-dose pitavastatin (4 mg/day × 4 days) on the day before and of the procedure and 2 days after the procedure (Statin group, n=213) or no pitavastatin (Control group, n=207). Isotonic saline hydration combined with a single bolus of sodium bicarbonate (20 mEq) was scheduled for administration to all patients. In the control group, statin therapy was continued at the same dose as that before randomization. CIN was defined as a ≥0.5 mg/dL increase in serum creatinine or ≥25% above baseline at 48 h after contrast exposure. Before randomization, 83% of study participants were receiving statin treatment. The statin group had a higher incidence of CIN than the control group (3.0% vs. 0%, P=0.01). The 12-month rate of major adverse cardiovascular events was similar between the 2 groups. CONCLUSIONS: High-dose pitavastatin increases the incidence of CIN in this study population.

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.

Outpatient cardiac rehabilitation dose after acute coronary syndrome in a nationwide cohort.

OBJECTIVE: Cardiac rehabilitation (CR) is effective in patients with acute coronary syndrome (ACS); however, CR programmes have not been fully implemented. This study aimed to reveal the current practice of outpatient CR and the dose-effect relationship of CR in real-world settings. METHODS: We performed a nationwide retrospective cohort study using the National Database of Health Insurance Claims and Specific Health Checkups of Japan. Patients with ACS who underwent percutaneous coronary intervention between April 2014 and March 2018 were included. We analysed the implementation rate and dose of outpatient CR and the association between dose and outcomes. RESULTS: Out of 202 320 patients who underwent percutaneous coronary intervention for ACS, a total of 20 444 (10%) underwent outpatient CR. The median (IQR) number of total CR sessions was 9 (3-17), and the median (IQR) duration for each session was 60 (42-60) min. Patients were divided into four groups according to the total number of sessions (≤9 times or ≥10 times) and the duration per session (<50 min or ≥50 min). Compared with the low-number/short-duration group, the adjusted HR for all-cause mortality was 1.00 (95% CI 0.80 to 1.24, p=0.97) in the low-number/long-duration group, 0.63 (95% CI 0.46 to 0.87, p=0.005) in the high-number/short-duration group and 0.74 (95% CI 0.60 to 0.92, p=0.008) in the high-number/long-duration group, respectively. CONCLUSION: We found that the participation rate for outpatient CR after ACS was low and the doses of sessions vary in real-world settings. A higher number of total sessions of outpatient CR is associated with a better prognosis irrespective of the session's duration.

Outcomes of catecholamine and/or mechanical support in Takotsubo syndrome.

OBJECTIVE: This study aimed to reveal the clinical characteristics of patients with severe Takotsubo syndrome (TTS) who needed catecholamine support (CS) or mechanical support (MS) and to identify factors associated with serious illness and in-hospital mortality. METHODS: This was a nationwide retrospective study that used claims data from the Japanese registry of all cardiac and vascular diseases and the diagnosis procedure combination registry, from April 2012 to March 2016. The patients with TTS were divided into severe TTS and mild TTS groups. The severe group was defined as patients who needed CS and/or MS. RESULTS: Among 6169 patients with TTS, 1148 (18.6%) had severe TTS. No significant difference in age was found between the two groups; however, the number of female patients was significantly lower in the severe group than in the mild group. Among 130 patients who underwent MS, 22 and 108 patients required MS alone and both MS and CS, respectively. The 30-day mortality rate was significantly higher in the severe group than in the mild group (11.4% vs 2.6%, p<0.01) and increased with age. Of the patients with severe TTS, 65.6% died within 7 days. Multivariable analysis showed that male sex (OR 1.22, p=0.03), higher Charlson scores (OR 1.11, p<0.01), comorbid pneumonia (OR 1.68, p<0.01), comorbid sepsis (OR 6.02, p<0.01) and ambulance use (OR 2.01, p<0.01) were associated with severe TTS. CONCLUSIONS: The rate of severe TTS was 18.6% among 6169 patients registered in the Japanese nationwide database, and the 30-day mortality was higher in patients with severe TTS than in those with mild TTS (11.4% vs 2.6%).

Detection of myocardial bridge by optical coherence tomography.

Myocardial bridge (MB) is less commonly documented by angiography than autopsy. Optical coherence tomography (OCT) may be useful to detect angiographically undetectable MB. To investigate OCT characteristics of MB, 86 LAD vessels were imaged by OCT. MB was defined as presence of intermediate optical intensity, "fine" layer surrounding coronary artery by OCT. Frequency and characteristics of the angio-detectable and angio-undetectable but OCT-detectable MB were investigated. In a subset of patients with angio-detectable MB, cyclic changes in coronary arterial dimensions were analyzed. OCT detected MB in 44 of 86 (51%). Arc of the MB was significantly larger (334.8 ± 58.5° vs. 268.4 ± 92.1°, P = 0.008) and length was significantly longer (22.6 ± 11.7 mm vs. 14.5 ± 8.1 mm, P = 0.014) in angio-detectable MB than OCT-detectable but angio-undetectable MB. Both vessel (6.8 ± 1.5 to 5.3 ± 1.0 mm2, P = 0.035) and lumen area (4.4 ± 1.5 to 3.1 ± 0.7 mm2, P = 0.040) decreased significantly from diastole to systole. Adventitial (0.08 ± 0.03 to 0.08 ± 0.02 mm, P = 0.828) and intima + plaque thickness (0.12 ± 0.05 to 0.10 ± 0.03 mm, P = 0.398) did not change significantly during cardiac cycle. On the other hand, medial thickness increased significantly from diastole to systole (0.08 ± 0.03 to 0.12 ± 0.03 mm, P = 0.022). In conclusion, MB is frequently detected as intermediate intensity, fine layer by OCT. During systole, vessel and lumen size decrease with increased medial thickness. Therefore, we should be careful for OCT interpretation of the coronary arteries with MB.