Prognostic impact of increase in left atrial volume following left atrial appendage closure: Insights from the OCEAN-LAAC registry.

Background: Percutaneous left atrial appendage closure (LAAC) is an effective therapy to prevent thromboembolic events among patients with atrial fibrillation (AF). However, since the left atrial appendage (LAA) contributes to left atrial volume and serves as a buffer for increasing left atrial pressure, this procedure may impair left atrium (LA) compliance, enlarge LA, and deteriorate diastolic function. In this study, we sought to investigate the change in left atrial volume index (LAVI) following LAAC and its effect on prognosis. Methods and Results: We analyzed 225 patients from the OCEAN-LAAC registry, an ongoing, multicenter Japanese study. Comparing LAVI measurements at baseline and 6 months after LAAC, no significant increase was observed (55.0 [44.0, 70.0] ml/m2 vs. 55.0 [42.0, 75.6] ml/m2; P = 0.31). However, some patients underwent LAVI increase. Particularly, a smaller LAVI (odds ratio [OR]: 0.98 [95 % confidence interval (CI): 0.97-0.996]) and elevated tricuspid regurgitation pressure (TRPG) at baseline (OR: 1.04 [95 % CI: 1.00 - 1.08]) were significantly related to the increase in LAVI at 6-month follow-up. In addition, a 5 ml/m2 increase in LAVI was significantly associated with subsequent heart failure hospitalization (HFH) (hazard ratio: 3.37 [95 % CI: 1.18-9.65]). This association, however, was not observed in patients with lower baseline LAVI (≤55 ml/m2) but was only seen in those with a baseline LAVI over 55 ml/m2. Conclusion: Our study demonstrated an increase in LAVI after LAAC was related to smaller LAVI or elevated TRPG at baseline. The LAVI increase was significantly associated with subsequent HFH.

High-power application is associated with shorter procedure time and higher rate of first-pass pulmonary vein isolation in ablation index-guided atrial fibrillation ablation.

BACKGROUNDS: Ablation index (AI) is useful to complete circumferential pulmonary vein isolation (CPVI) for atrial fibrillation (AF), but the role of radiofrequency power in AI-guided CPVI remains to be elucidated. METHODS: We investigated 60 patients with AF undergoing AI-guided CPVI (mean age, 66 ± 9 years; nonparoxysmal AF in 16). The first 40 patients were randomly assigned to low-power (LP; n = 20) and medium-power (MP; n = 20) groups and the following 20 patients to high-power (HP). In LP, radiofrequency (RF) application was done at 30 W at the anterior and 20 W at the posterior left atrial (LA) wall, while in MP, it was at 40 W at the anterior and 30 W at the posterior LA wall. In HP, 50 W was applied at the anterior, 40 W at posterior LA wall and 30 W on the esophagus. At each ablation point, target AI was 400 at the anterior, 360 at the posterior LA wall, and 260 on the esophagus. RESULTS: The time to complete both-side CPVI was shortest in HP (median, 40 minutes, interquartile range [IQR], 28-63) followed by MP (58 [49-83] minutes, P = .008 vs HP) and LP (84 [72-93] minutes, P = .002 vs MP). Higher RF power application significantly increased first-pass isolation rate (55% in LP, 80% in MP and 85% in HP, P = .002) and decreased LA-PV reconnection rate (10% in LP, 8% in MP, and 0% in HP, P = .03). CONCLUSION: In AI-guided PVI, the HP RF application can shorten the time to complete PVI with a high rate of first-pass isolation and a low rate of LA-PV reconnection.

A case of cardiac sarcoidosis masquerading as arrhythmogenic right ventricular cardiomyopathy awaiting heart transplant.

We report a case of 45-year-old man, who was diagnosed with arrhythmogenic right ventricular cardiomyopathy (ARVC) and presented with right ventricular (RV) enlargement with a global decrease in RV contractility accompanied by impairment of left ventricular function. He was placed on the heart transplant waiting list. Endomyocardial biopsy from RV septal wall did not show any evidence of sarcoidosis or inflammatory change. Four years after he was put on the heart transplant waiting list, a computed tomography chest scan for the purpose of anatomical evaluation for coronary sinus prior to biventricular pacing lead implantation incidentally showed bilateral hilar lymphadenopathy, which suggested the possibility of sarcoidosis. Biopsy of the inguinal lymph node pathologically was consistent with sarcoidosis. The 2[18F]fluoro-2-deoxy-d-glucose positron emission tomography scanning (FDG-PET) demonstrated intense uptake in the myocardium, and the patient was finally diagnosed as having cardiac sarcoidosis. After steroid treatment, the abnormal FDG-PET uptake disappeared. The patient therefore represented a case of cardiac sarcoidosis masquerading as ARVC. It should be recognized that RV involvement is one of the manifestations in cardiac sarcoidosis.