Abstract 3617: The Relation of New Atrial Fibrillation to Cardiovascular and All-Cause Mortality During Treatment of Hypertension: The LIFE Study
Background: Atrial fibrillation (AF) has been associated with an increased risk of death, with recent findings suggesting that newly diagnosed AF predicts an increased risk of mortality compared with an age and gender-matched population, particularly early after diagnosis. However, new AF is frequently associated with other cardiovascular (CV) diseases and risk factors that can impact on mortality, and whether new AF is an independent predictor of death has not been clearly established.
Methods: Mortality was assessed in relation to new AF in 8831 hypertensive patients with no history of AF and no AF on their baseline ECG who were treated with losartan- or atenolol-based regimens. New AF was ascertained by annual study ECG and by adverse event reports from investigators.
Results: During mean follow-up of 4.8±0.9 years, AF developed in 701 patients (7.9%). Mean follow-up was 2.1±1.6 years after new AF vs 4.8±0.9 years in patients who did not develop AF (p<0.001). CV death (CVD) occurred in 379 patients (4.3%) and all-cause death (ACD) in 732 (8.3%) and each was more common among patients who developed AF: 10.1 vs 3.8% and 16.3 vs 7.6%, both p<0.001. In univariate Cox analyses that considered new AF as a time-varying categorical variable, development of new AF predicted increased risks of CVD (HR 1.84, 95% CI 1.34 –2.54) and ACD (HR 1.42, 95% CI 1.10 –1.83). After adjusting for incident MI prior to new AF, in-treatment blood pressure, ECG left ventricular hypertrophy, heart rate and QRS duration and for baseline risk factors of age, sex, race, total and HDL cholesterol, serum creatinine and glucose, urine albumin/creatinine ratio and a history of heart failure, MI, ischemic heart disease and diabetes, development of new AF was no longer a statistically significant predictor of CVD (HR 1.21, 95% CI 0.85–1.71) or ACD (HR 0.98, 95% CI 0.75–1.30).
Conclusions: The association of new AF during treatment of hypertension with subsequent CVD or ACD in short-term follow-up is not significant after taking into account the greater CV risk factors and higher prior incidence of MI in patients with new AF. These findings suggest that the increased mortality associated with new AF in hypertensive patients is primarily mediated by CV risk factors and diseases that predispose to developing AF.