Elevated left ventricular filling pressure estimated by E/E′ ratio after exercise predicts development of new-onset atrial fibrillation independently of left atrial enlargement among elderly patients without obvious myocardial ischemia

Abstract

ObjectiveTo determine whether elevated left ventricular (LV) filling pressure estimated by raised Doppler E velocity to tissue Doppler E′ velocity ratio (E/E′) after exercise is associated with increased risk of new-onset atrial fibrillation (AF) in non-ischemic elderly patients. BackgroundPrognostic importance of exercise induced LV diastolic dysfunction remains uncertain. Patients and methodsWe studied 147 elderly patients (73±5 years) who underwent treadmill stress echocardiography. Patients with exercise induced LV wall motion abnormality were not included. Doppler and tissue Doppler measurements were done before treadmill exercise and immediately after the post-stress image acquisition, and E/E′ ratio was measured. Raised E/E′ was defined as E/E′≥15, and left atrial (LA) enlargement was defined as LA volume index≥34ml/m2. Using Cox proportional hazards regression analysis, predictor of new-onset AF was determined. Using Kaplan–Meier analysis, we evaluated association between raised post-exercise E/E′ or LA enlargement with new-onset AF. ResultsDuring the follow-up period (median=67 months), there were 25 new-onset AF. Cox proportional hazards regression analysis demonstrated that male gender [hazard ratio (HR) 3.294; p=0.0117], LA enlargement (HR 3.576; p=0.0017), and raised post-exercise E/E′ (HR 3147; p=0.0068) were the best predictors of new-onset AF. Kaplan–Meier survival plot demonstrated that patients with both LA enlargement and raised post-exercise E/E′ developed new-onset AF most frequently. There was no significant difference in outcome between patients with isolated raised post-exercise E/E′ or isolated LA enlargement. ConclusionsRaised E/E′ ratio after exercise provides significant prognostic information for predicting new-onset AF in non-ischemic elderly patients. This prognostic value of raised post-exercise E/E′ is independent of and incremental to the LA enlargement.