Left atrial volume in the prediction of first ischemic stroke in an elderly cohort without atrial fibrillation

OBJECTIVE: To determine the clinical Importance of left atrial (LA) volume in the prediction of first ischemic stroke. PATIENTS AND METHODS: This retrospective cohort study included randomly selected residents of Olmsted County, Minnesota, aged 65 years or older, who had undergone transthoracic echocardiography at least once at the Mayo Clinic in Rochester, Minn, between January 1, 1990, and December 31, 1998, were in sinus rhythm, and had no history of stroke, transient ischemic attack, atrial fibrillation, or valvular heart disease. Patients were monitored through medical records for first ischemic stroke or death. RESULTS: Of 1554 residents (59% women) aged 75 +/- 7 years, 92 (6%) had experienced at least I ischemic stroke over 4.3 +/- 2.7 years (incident stroke rate, 1.4 per 100 person-years). Left atrial volume of 32 mL/m(2) or greater (hazard ratio [HR], 1.63; confidence interval [CI], 1.08-2.46) was independent of age (MR, 1.04; Cl, 1.02-1.07), diabetes (HR, 1.91; CI, 1.07-3.41), myocardial infarction (MR, 1.64; Cl, 1.01-2.64), and hyperlipidemia (HR, 1.55; Cl, 1.01-2.37) for the prediction of first ischemic stroke. When quartiles of LA dimension were plotted against quartiles of indexed LA volume, a stepwise increase in risk with each quartile increment was evident only for indexed LA volume. Also, an LA volume of 32 mL/m(2) or greater was associated with an increased mortality risk (MR, 1.30; Cl, 1.09-1.56), independent of age, sex, and stroke status. CONCLUSIONS: In our elderly cohort with no prior atrial fibrillation, LA volume was independently predictive of first ischemic stroke, incremental to age, diabetes, myocardial infarction, and hyperlipidemia. It was also an independent predictor of death.