Risk stratification for recurrent heart failure in patients post-myocardial infarction with electrocardiographic and echocardiographic left atrial abnormality

Left atrial enlargement is predictive of cardiovascular events. The predictive power, however, of the combination of electrocardiographic (LAE-ECG) and echocardiographic left atrial enlargement (LAE-Echo) has not been extensively evaluated. We prospectively identified patients admitted with non-ST-segment elevation myocardial infarction (NSTEMI) who developed new-onset heart failure during admission. Baseline electrocardiograms obtained <= 12 months before admission were evaluated for LAE-ECG, such as prolonged P-wave duration or positive P-wave terminal force in lead V1, and in-hospital echocardiographic reports obtained <= 1 month after admission were assessed for linear, anteroposterior LAE-Echo. Follow-up was directed toward pertinent cardiovascular events and death. Of the 462 patients with NSTEMI, 108 developed new-onset heart failure (23%); 71 patients had LAE-Echo. Follow-up was 23.2 months (mean 22.1 months). Although in-hospital (early) cardiovascular complications (other than heart failure) were not significantly higher in patients with LAE-Echo, these patients demonstrated more postdischarge (late) cardiovascular complications, predominantly recurrent heart failure. In addition, those with a combination of LAE-Echo and LAE-ECG demonstrated significantly higher recurrence of heart failure (hazard ratio 1.52, 95% confidence interval 1.12 to 4.35; p = 0.02 for interatrial conduction delay, and hazard ratio 1.07, 95% confidence interval 1.01 to 3.27 for P-wave terminal force in lead V1; p = 0.03) and increased mortality compared with those with LAE-Echo alone. In conclusion, our data suggest that a combination of electrical and mechanical left atrial dysfunction is significantly more predictive of increased cardiovascular events and mortality compared with left atrial mechanical dysfunction alone. (C) 2008 Elsevier Inc. All rights reserved.