Abstract 3701: Better Preservation of Left Atrial Systolic Force By Losartan may Contribute to Lower Incidence of New-onset Atrial Fibrillation: The LIFE study
Background: In hypertensive patients enhanced left atrial (LA) systolic force (LASF), a recently-introduced measure of active LA function, is associated with LV hypertrophy and increased preload. However, it is unknown whether LASF is related to new-onset atrial fibrillation (AF) in hypertensive patients.
Methods: Hypertensive patients with electrocardiographic (ECG) left ventricular (LV) hypertrophy were randomized to atenolol or losartan-based regimens in the LIFE Study. Patients without prevalent AF underwent Doppler echocardiography (n=768) and were followed for 3,657 patient-years with ECGs and echocardiograms at enrolment and annually during treatment. LASF was obtained from mitral orifice area and Doppler mitral peak atrial velocity.
Results: Baseline LASF predicted lower risk of new-onset AF (HR=0.92/1 kdyn higher LASF [95%CI: 0.87– 0.98], p=0.008). In time-varying Cox regression analyses adjusting for age, gender, body mass index, study treatment, time-varying systolic blood pressure and time-varying left ventricular mass index, higher LASF was associated with 10% lower risk per kdyn of new-onset AF (HR= 0.90, 95% CI: 0.85– 0.96, p=0.001). Losartan-based treatment preserved LASF significantly more than atenolol-based treatment (Table⇓) during the trial.
Conclusion: Low LASF at baseline and especially during antihypertensive treatment is a novel predictor of new-onset AF independent of the level of arterial pressure and other covariates. Losartan preserved LASF better than atenolol-based treatment, potentially contributing to less new-onset AF with losartan treatment.