Predictive value of echocardiographic left atrial size for incident stoke and stroke cause mortality: a population-based study.

Abstract

To investigate the associations between echocardiographic left atrial (LA) size and incident stoke and stroke cause mortality among a rural population in China. A prospective study. Based on the Northeast China Rural Cardiovascular Health Study, we selected a total of 10 041 participants aged ≥35 years who agreed to have transthoracic echocardiography at baseline and were successfully followed up for incident stoke and stroke cause mortality. The outcomes were stroke and stroke cause death according to medical records and death certificates during the follow-up period. LA enlargement (LAE) group had a higher prevalence of cardiovascular disease than normal LA diameter (LAD) group. After excluding individuals who had a prior stroke, subjects with LAE showed higher incident rates of stroke and its mortality in the overall and specific stratified analyses (all p<0.05). Kaplan-Meier analysis revealed that LAE could predict stroke incidence and stroke-free survival, but the association was no longer observed after the adjustment for potential confounding factors. Cox regression analysis reported that per 1 SD increment in LAD and LAD/body surface area (BSA) was associated with an increased incidence of stroke (LAD: HR=1.20, 95% CI 1.08 to 1.33, p<0.001; LAD/BSA: HR=1.22, 95% CI 1.11 to 1.35, p<0.001) and stroke cause mortality (LAD: HR=1.27, 95% CI 1.08 to 1.50, p<0.01; LAD/BSA: HR=1.41, 95% CI 1.20 to 1.65, p<0.001) in the total population, and similar trends were found in both genders (all p<0.05). LAD or LAD/BSA was related to ischaemic and haemorrhagic stroke incidence, and the risk of ischaemic and haemorrhagic stroke mortality (all p<0.05). The dose-response curves further suggested linear associations between LAD, LAD/BSA and the incidence of stroke and subsequent mortality in the general population (all p<0.05). Our population-based study implied that LA size, especially LAD and LAD/BSA, might be useful echocardiographic biomarkers that had the potential to predict incident stroke and stroke cause mortality.