OP.7B.06] RELATIONSHIP OF INCIDENT ATRIAL FIBRILLATION TO THE ELECTROCARDIOGRAPHIC STRAIN PATTERN IN HYPERTENSIVE PATIENTS WITH ELECTROCARDIOGRAPHIC LEFT VENTRICULAR HYPERTROPHY

Abstract

Objective: Atrial fibrillation (AF) is strongly related to hypertension and to left ventricular hypertrophy (LVH), and both regression of ECG-LVH and achievement of lower systolic blood pressure (SBP) are associated with lower incidence of AF. The ECG strain pattern of lateral ST depression and T-wave inversion has been associated with more severe LVH, decreased LV systolic function and an increased risk of cardiovascular morbidity and mortality, including new heart failure (HF). However, whether ECG strain is associated with an increased risk of new AF is unclear. Design and method: Risk of new-onset AF was examined in relation to the presence of the strain pattern on baseline ECG in 7921 hypertensive patients with ECG-LVH with no history of AF, who were in sinus rhythm on their baseline ECG, had baseline strain determination and were randomized to losartan- vs. atenolol-based treatment. Results: During 4.7 ± 1.1 yrs. of follow-up, new-onset AF was diagnosed in 621 patients (7.8%). Baseline ECG strain was present in 882 patients (11.1%) and was associated with a significantly higher 5-yr. incidence of AF in Kaplan-Meier estimates (12.2 vs 7.4%, p < 0.001) and with a 66% greater risk of new AF in a univariate Cox model (HR 1.66, 95% CI 1.34–2.06, p < 0.001), compared with the absence of ECG strain. After adjusting for other univariate predictors of new AF in this population, including age, sex, race, prior anti-hypertensive treatment, randomized treatment allocation, prevalent diabetes, history of ischemic heart disease, prior myocardial infarction, stroke or HF, baseline serum cholesterol and urine albumin/creatinine ratio entered as standard covariates and incident HF and on-treatment diastolic BP, SBP, heart rate and Cornell product LVH entered as time-varying covariates, ECG strain remained associated with a 39% greater risk of new-onset AF (HR 1.39, 95% CI 1.09–1.76, p = 0.008). Conclusions: The presence of baseline ECG strain is strongly associated with an increased risk of developing new-onset AF in hypertensive patients with ECG-LVH, independent of other AF risk factors and the effects of incident HF, LVH regression and SBP reduction. These findings suggest that hypertensive patients with ECG strain should be followed for development of new AF.