Background: Adverse atrial remodeling, including epicardial adipose tissue (EAT) deposition in the left atrium (LA), is implicated in atrial fibrillation (AF). Radiofrequency hotballoon (RHB) ablation can produce wide planar lesions because the balloon is highly compliant; however, chronic effects of RHB ablation on structural remodeling remain unknown. This clinical-experimental investigation characterized chronic effects of RHB ablation on EAT in persistent AF (PsAF).

Methods and Results: The clinical study involved 91 patients (obese, n=30; non-obese, n=61) undergoing RHB ablation for PsAF. LA-EAT was assessed from computed tomography images obtained before ablation and 6 months later. Tissue effects of RHB ablation were explored in a chronic swine model. RHB ablation significantly reduced LA volume (mean [±SD] 177.7±29.7 vs. 138.4±29.6 mL; P<0.001) and LA-EAT volume (median [interquartile range] 22.0 [12.4–33.3] vs. 16.5 [7.9–25.8] mL; P<0.001). The reduction in EAT was significantly greater in the pulmonary vein (PV) antrum than in other LA regions (37.9% vs. 15.8%; P<0.001). The percentage reduction in PV antrum EAT was equivalent between obese and non-obese patients, as was the postablation success rate (73% vs. 70%; P=0.77). RHB ablation produced transmural lesions reaching the pigs’ epicardial fat region.

Conclusions: RHB-based planar-transmural lesions altered the structurally remodeled LA, including EAT. Further studies are needed to determine whether factors other than PV isolation contribute to the clinical success of RHB ablation.

Background: During the COVID-19 pandemic, cardiovascular hospitalizations decreased and in-hospital mortality for ST-elevation myocardial infarction and heart failure increased. However, limited research has been conducted on hospitalization and mortality rates for cardiovascular disease (CVD) other than ischemic heart disease and heart failure.

Methods and Results: We analyzed the records of 530 certified hospitals affiliated with the Japanese Circulation Society obtained from the nationwide JROAD-DPC database between April 2014 and March 2021. A quasi-Poisson regression model was used to predict the counterfactual number of hospitalizations for CVD treatment, assuming there was no pandemic. The observed number of inpatients compared with the predicted number in 2020 was 88.1% for acute CVD, 78% for surgeries or procedures, 77.2% for catheter ablation, and 68.5% for left ventricular assist devices. Furthermore, there was no significant change in in-hospital mortality, and the decrease in hospitalizations for catheter ablation and valvular heart disease constituted 47.6% of the total decrease in annual hospitalization costs during the COVID-19 pandemic.

Conclusions: Cardiovascular hospitalizations decreased by more than 10% in 2020, and the number of patients scheduled for left ventricular assist device implantation decreased by over 30%. In addition, in response to the COVID-19 pandemic, annual cardiovascular hospitalization costs were reduced, largely attributed to decreased catheter ablation and valvular heart disease.

Background: Triple combination therapy with a renin–angiotensin system modulator, a β-blocker, and a mineralocorticoid receptor antagonist is currently recommended for patients with heart failure (HF) with reduced ejection fraction. However, there is limited evidence on the extent to which triple combination therapy is currently prescribed to patients at the time of discharge from hospital in Japan.

Methods and Results: Japanese patients hospitalized for HF (n=3,582) were evaluated in subgroups defined by left ventricular ejection fraction (LVEF) using anonymized claims and electronic health record data. At discharge, triple combination therapy prescription rates were low (40.4%, 30.0%, 20.8%, 14.0%, and 12.5% for patients with LVEF <30%, 30–<40%, 40–<50%, 50–<60%, and ≥60%, respectively). Advanced age, lower levels of B-type natriuretic peptide, and renal impairment were all significantly associated with lower rates of triple combination therapy use in the overall population. There were no significant differences in rehospitalization rates between LVEF subgroups; however, triple combination therapy use was associated with a significantly reduced risk of rehospitalization for HF in patients with LVEF <30%, 30–<40%, and 40–<50%.

Conclusions: The use of triple combination therapy was significantly associated with a lower risk of rehospitalization for HF within 1 year of discharge in patients with LVEF <30%, 30–<40%, and 40–<50%. However, patients were undertreated with triple combination therapy.