Catheter ablation is associated with reduced cardiovascular events in atrial fibrillation patients with atrial functional mitral regurgitation.

In 30 seconds

This multicentre observational study used China-AF registry data to compare catheter ablation (CA) with medical therapy in patients with atrial fibrillation and moderate or severe atrial functional mitral regurgitation. It explicitly emulated a parallel-group randomized target trial and balanced baseline covariates using weighting. Among 873 patients followed for a median of 1509 days, the primary outcome occurred in 22 CA patients and 42 receiving medical therapy; incidence was 1.76 vs 3.30 per 100 person-years, with a weighted hazard ratio of 0.55 (95% CI 0.32-0.94). The authors state that randomized trials are needed to confirm the association.

Key findings

• Primary outcome incidence was 1.76 vs 3.30 per 100 person-years with CA versus medical therapy; weighted HR 0.55 (95% CI 0.32-0.94).
• CA was associated with lower hazards of AF recurrence (HR 0.31; 95% CI, 0.25-0.37), cardiovascular death (HR 0.48; 95% CI, 0.24-0.96), and all-cause death (HR 0.49; 95% CI, 0.27-0.89).
• No significant differences were observed in ischemic stroke/systemic embolism, major bleeding, or cardiovascular hospitalization.

Why it matters

Atrial functional mitral regurgitation commonly accompanies atrial fibrillation, but whether ablation improves longer-term cardiovascular outcomes has been uncertain. This study reports an association between ablation and fewer primary outcome events, alongside lower observed hazards for recurrence and death. The findings add outcome data beyond changes in regurgitation severity, while the observational design means they do not establish that ablation caused these differences.

What to keep in mind

Treatment was assigned according to baseline care rather than randomization. Despite target-trial emulation and covariate weighting, residual confounding may remain; the authors call for confirmation in randomized controlled trials.