Effect of blood pressure lowering treatment on the risk of atrial fibrillation: an individual-participant data meta-analysis

Abstract

Abstract Background Although observational studies have suggested an association between elevated blood pressure (BP) and increased risk of atrial fibrillation (AF), randomised evidence on the effects of pharmacological blood pressure lowering on the risk of new-onset AF remains limited. Purpose To investigate the effects of pharmacological BP lowering on the risk of AF overall and stratified by baseline risk of AF and by drug class. Methods We extracted individual participant data from trials with over 1,000 person-years of follow-up that had randomly assigned patients to different classes of BP-lowering drugs, BP-lowering drugs vs placebo, or to more vs less intensive BP-lowering regimens. We investigated the effects of BP lowering on the risk of new-onset AF using fixed-effect one-stage individual participant data meta-analyses based on Cox proportional hazards models stratified by trial. Results Twenty-one trials were included with a total of 194,041 patients, in whom 6,357 new-onset and 516 recurrent AF events were recorded. The hazard ratio for new-onset AF was 1.01, 95% CI [0.95–1.07] per each 5-mmHg reduction in systolic BP, and meta-regression suggested that treatment effects were similar irrespective of the intensity of systolic BP reduction. Patients were overall at low risk of AF at baseline (median 2.3%, IQR [1.2–3.4%] at 5 years), and there was no evidence of heterogeneity in treatment effects across thirds of risk and 10-mmHg strata of baseline systolic BP (Figure). There was also no clear evidence that treatment effects differed between drug classes when renin-angiotensin-aldosterone system inhibitors and calcium channel blockers were compared with placebo and/or standard treatment. Conclusion In a low-risk population, pharmacological BP lowering did not reduce the risk of new-onset AF. Further research is needed to understand whether the effects would be different in high-risk individuals, and to better clarify the existence of class-specific effects. Figure 1. Forest plot Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): British Heart Foundation