ABSTRACT
BACKGROUND: Catheter ablation of atrial fibrillation (AF) is increasingly performed worldwide in patients with heart failure (HF). However, it has been recently emphasized that AF ablation in patients with HF is associated with increased risks of procedure-related complications and mortality. There are little data about the differences in the efficacy and safety between cryoballoon (CB) and radiofrequency (RF) ablation of AF in patients with HF. METHODS: The CRABL-HF study is designed as a prospective, multicenter, open-label, controlled, and randomized clinical trial comparing the efficacy and safety of AF ablation between CB and RF ablation in patients with HF (LVEF ≤40%) (UMIN Clinical Trials Registry UMIN000032433). The CRABL-HF study will consist of 110 patients at multicenter in Japan. The patients will be registered and randomly assigned to either the CB ablation or RF ablation group with a 1:1 allocation. The primary endpoint of this study is the occurrence of atrial tachyarrhythmias (ATs) at 1 year with a blanking period of 90 days after ablation. Key secondary endpoints are the success rate of the pulmonary vein isolation, total procedural time, left atrial dwelling time, total fluoroscopy time, radiation exposure, complication rate, composite of all-cause mortality or HF hospitalizations, cardiovascular events, change in left ventricular ejection fraction, and change in quality of life. RESULTS: The results of this study are currently under investigation. CONCLUSION: The CRABL-HF study is being conducted to compare the efficacy and safety of catheter ablation of AF between CB and RF ablation in patients with HF.
ABSTRACT
OBJECTIVE: Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) effectively interfere with the sympathetic nerve activity in patients with left ventricular (LV) dysfunction. The aim of this study was to examine the effect of ARBs on sympathetic nerve activity and baroreflex function in patients with LV dysfunction already receiving ACE inhibitors. METHODS: Twenty patients with LV dysfunction already treated with ACE inhibitor (enalapril 5 mg/day) were randomly divided into two groups: treatment with 10 mg/day enalapril (control group) or 5 mg/day enalapril plus 80 mg/day valsartan (combination group). In both groups, resting muscle sympathetic nerve activity (MSNA; microneurography), arterial baroreflex sensitivity, and cardiopulmonary baroreflex sensitivity were measured at baseline and 4 weeks after the treatment. Arterial baroreflexes were perturbed by phenylephrine method, and cardiopulmonary baroreflexes were perturbed by lower body negative pressure (-10 mmHg). RESULTS: Baseline characteristics in both groups were similar. Resting MSNA decreased significantly from 35.4+/-10.8 to 26.4+/-5.1 burst/min (p<0.05), while arterial baroreflex sensitivity improved significantly from 6.0+/-2.0 to 10.1+/-2.6 ms/mmHg in the combination group. Moreover, cardiopulmonary baroreflex control of MSNA improved significantly from 15.8+/-12.2 to 42.0+/-26.7% (p<0.05) in the combination group. However, there were no significant changes in arterial baroreflex sensitivity and cardiopulmonary baroreflex of MSNA in the control group. CONCLUSION: Addition of ARB to ACE inhibitor treatment reduced sympathetic nerve activity and augmented arterial and cardiopulmonary baroreflex sensitivity in patients with LV dysfunction.
