Incidence and Implications of Atrial Fibrillation/Flutter in Hypertension: Insights From the SPRINT Trial

Abstract

We evaluated the impact of intensive blood pressure control on the incidence of new-onset atrial fibrillation/flutter (AF) and the prognostic implications of preexisting and new-onset AF in SPRINT (Systolic Blood Pressure Intervention Trial) participants. New-onset AF was defined as occurrence of AF in 12-lead electrocardiograms after randomization in participants free of AF at baseline. Poisson regression modeling was used to calculate incident rates of new-onset AF. Multivariable-adjusted Cox proportional hazard models were used to evaluate the risk of adverse cardiovascular events (composite of myocardial infarction, non-myocardial infarction acute coronary syndrome, stroke, heart failure, or cardiovascular death). In 9327 participants, 8.45% had preexisting AF, and 1.65% had new-onset AF. The incidence of new-onset AF was 4.53 per 1000-person years, with similar rates in the standard and intensive treatment arms (4.95 versus 4.11 per 1000-person years; adjusted P=0.14). Participants with preexisting AF (adjusted hazard ratio, 1.83 [95% CI, 1.46-2.31]; P<0.001) and new-onset AF (adjusted hazard ratio, 2.45 [95% CI, 1.58-3.80]; P<0.001) had a greater risk for development of adverse cardiovascular events compared with those with no AF. Participants with preexisting AF who achieved blood pressure <120/80 mm Hg at 3 months continued have a poor prognosis (adjusted hazard ratio, 1.88 [95% CI, 1.32-2.70]; P=0.001) compared with those with no AF. Intensive blood pressure control does not diminish the incidence of new-onset AF in an older, high-risk, nondiabetic population. Both preexisting and new-onset AF have adverse prognostic implications. In participants with preexisting AF, residual cardiovascular risk is evident even with on-treatment blood pressure <120/80 mm Hg. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT01206062.

Keywords: atrial fibrillation; blood pressure; heart failure; hypertension; incidence; myocardial infarction; stroke.

Conflict of interest statement

Conflicts of Interest

None of the authors had any conflicts of interest or financial disclosures to declare.

Figures

Figure 1.. Incidence of New-Onset Atrial Fibrillation/Flutter: Stratified by Treatment Strategy

Panel A: Cumulative incidence of new-onset atrial fibrillation/flutter stratified by treatment strategy. Panel B: Incidence rate of AF in participants randomized to intensive (blue) and standard (green) blood pressure management. IRR: Incidence rate ratio.

Figure 2.. Ranking of Strength of Association Between New-Onset Atrial Fibrillation/Flutter and Clinical and Demographic Factors

This figure demonstrates the relative strength of association of respective covariates, ranked according to chi-squared values from the multivariate-adjusted model. Chi-square values were corrected for degrees of freedom allocated to respective covariates in the model ensuring comparison on same scale.

Figure 3.. Prognostic Implications of New-Onset and Pre-Existing Atrial Fibrillation/Flutter

Adjusted Kaplan-Meier curves for the risk of development of adverse cardiovascular events. The curve represents participants with new-onset (green), pre-existing (red), and no atrial fibrillation/flutter (blue).

Figure 4.. Residual Cardiovascular Risk in Participants with Pre-Existing Atrial Fibrillation/Flutter

Adjusted Kaplan-Meier curves for the risk of development of adverse cardiovascular events. The blue curve represents participants free of atrial fibrillation/flutter (AF). Those with pre-existing AF and having attained blood pressure