Abstract
BACKGROUND: Previous epidemiological studies demonstrated that premature atrial contractions (PACs) and premature ventricular contractions (PVCs) detected by single 12-lead ECGs can predict incident cardiovascular disease and death. The determinants of cardiac ectopy remain unknown, with some evidence that hypertension may contribute. OBJECTIVE: To determine if intensive blood pressure (BP) control reduces the incidence of cardiac ectopy. METHODS: We performed a post-hoc analysis of the Systolic Blood Pressure Intervention trial, which randomised hypertensive participants to standard treatment (BP target <140 mm Hg) or intensive treatment (<120 mm Hg) with ECGs obtained at baseline, 2 years, 4 years and 5 years. The primary outcomes were incidence of ectopy (PACs or PVCs) as coded by Minnesota ECG classification, censoring for pacing, atrioventricular block, pre-excitation or atrial fibrillation/flutter. We performed Cox proportional hazards regression to determine the association of treatment group with outcomes. RESULTS: The analysis cohort comprised 3910 participants randomised to standard treatment and 3911 to intensive treatment, of whom 452 had ectopy on baseline ECG. After excluding those with baseline ectopy, there was no significant difference in the incidence of ectopy (incidence rate ratio 0.93 (95% CI 0.81 to 1.05)). There was no significant association between treatment group and ectopy incidence, with an unadjusted Cox HR of 0.93 (95% CI 0.82 to 1.07), and HR of 1 (95% CI 0.81 to 1.25) after adjusting for covariates. CONCLUSION: Intensive BP control did not reduce the incidence of cardiac ectopy in patients with hypertension. Given the variable nature of PAC and PVC burden, further studies with continuous monitoring or more frequent sampling in larger populations are warranted.