The Effects of Rate and Rhythm Control on Blood Pressure and Antihypertensive Drug Usage in Patients with Atrial Fibrillation and Hypertension Enrolled in the AFFIRM Trial

Abstract

Atrial fibrillation (AF) has been shown to be associated with activation of the renin-angiotensin-aldosterone system, endothelial dysfunction, and increased sympathetic activity, all of which could lead to hypertension (HTN). While the effects of HTN on AF incidence and arrhythmogenesis have been reported, the long-term effects of AF on blood pressure (BP) remain unknown. We hypothesized that a rate control strategy is associated with an increase in BP and/or antihypertensive drug therapy when compared with a rhythm control strategy in patients with a history of AF and HTN. Using the intention to treat method, BP readings and the number of antihypertensive medication categories were analyzed over the first year of follow-up in patients with AF and HTN enrolled in the AFFIRM trial. No clinically significant changes in BP occurred. Medication data were available in 2,876 patients. In the rate control group, 27.8% of patients required a net increase in the number of antihypertensive medications when compared to 18.3% in the rhythm control group (P < 0.001). Furthermore, 27.1% of patients in the rate control group had a net decrease in the number of antihypertensive medications when compared with 41.7% in the rhythm control group (P < 0.001). Our findings suggest that AF could be contributing to BP elevation in patients with a history of HTN and that a rhythm control strategy might result in a decrease in BP in these patients. This hypothesis however, requires future testing.