Clinical and pathophysiologic determinants of catheter ablation outcome in hypertrophic cardiomyopathy with atrial fibrillation.

Background: Hypertrophic cardiomyopathy (HCM) is frequently associated with atrial fibrillation (AF). We compared clinical, echocardiographic, and electrophysiological parameters between HCM subtypes and those without HCM at AF catheter abla- tion (AFCA) and analyzed post-AFCA reverse remodeling and AF recurrence based on HCM presence and subtype. Methods: Among 5161 consecutive patients who underwent de novo AFCA, we included HCM patients and control patients who were age-, gender-, and AF type- matched. Between AF-HCM patients and controls, we compared baseline values for left atrium (LA) wall thickness (LAWT), reverse remodeling at 1-year follow-up, and procedural outcomes over the course of follow-up between two groups. Results: A total of 122 AF-HCM patients and 318 control patients were included. AF- HCM patients had more frequent heart failure and higher LA diameter, E/Em, and LA pressure (all, p < .001). However, LAWT did not differ from control group. A year after AFCA, degree of LA reverse remodeling was significantly lower in AF-HCM than in control group (ΔLA dimension, p = .025). Nonapical HCM (HR 1.71; 95% CI 1.05--2.80), persistent AF (HR 1.46; 95% CI 1.05--2.04), and LA dimension (HR 1.04; 95% CI 1.01-- 1.06) were independent risk factors for AF recurrence. During 78.0 months of follow- up, nonapical HCM patients showed higher AF recurrence rate than both apical HCM (log-rank p = .005) and control patients (log-rank p = .002). Conclusions: The presence of HCM, particularly nonapical HCM, displayed increased LA hemodynamic loading with diastolic dysfunction and had poorer rhythm outcomes after AFCA compared to both apical HCM and control group. [ABSTRACT FROM AUTHOR]