Rhythm Control Better Prevents Stroke than Rate Control in Patients with Concomitant Hypertrophic Cardiomyopathy and Atrial Fibrillation: A Nationwide Population Based Cohort Study with Long-Term Follow-Up

Background: Atrial fibrillation (AF) increases the risks of stroke and mortality. It remains unclear whether rhythm control reduces the risk of stroke in patients with AF concomitant with hypertrophic cardiomyopathy (HCM).

Methods: We identified AF patients with HCM who were ≥ 18 years old in the Taiwan National Health Insurance Database. Patients using antiarrhythmic medications for ≥ 30 defined daily doses (DDDs) or receiving catheter ablation for AF constituted the rhythm control group. Patients using rate control medications for ≥ 30 DDDs constituted the rate control group. A multivariable Cox regression model was used to evaluate the hazard ratio (HR) for adverse cardiovascular events.

Results: We enrolled a total of 178 patients with both AF and HCM without pre-existing cardiovascular diseases. Among them, 99 were in the rhythm control group and 79 were in the rate control group. After a follow-up period of 6.47 ± 0.98 years, the rhythm control group had a lower risk of stroke than the rate control group (adjusted HR: 0.380, p = 0.031) after adjusting for covariates including use of antithrombotic agents. After excluding patients receiving catheter ablation, the rhythm control group still had a lower risk of stroke than the rate control group (adjusted HR: 0.380, p = 0.037).

Conclusions: In patients with AF and HCM, rhythm control with mainly pharmacological treatment better prevented stroke than rate control in long-term follow-up. The beneficial effect of lowering stroke risk through rhythm control was independent of oral anticoagulant use.