Abstract
Background and Objectives: It is assumed that left atrial (LA) volume provides more accurate prognostic information about patients with acute myocardial information (AMI), because it presents severity of diastolic function impairment by the time. The aim of this study was to evaluate the effect of left atrium size on patients' outcome after acute myocardial infarction.
Materials and Methods: In this cohort study 100 patients with AMI during admission were entered into the study. The patients were followed up for 9 months. Their one month survival rate was evaluated. Demographic, atherosclerotic risk factors, arrhythmic and mechanical side effects of MI were recorded. Moreover, echocardiographic indices such as systolic and diastolic function and left atrial volume were evaluated.
Results: In our study patients with higher LA volume index (>32 mL/m2) had more mortality rate (6/22, 27.3%) compared to patients with lower LA index (1/78, 1.3%) (P= 0.001). There was no statistically significant difference in mortality rate considering gender and age of the patients (P>0.05). In univariate analysis, there was no statistically significant difference in mortality rate with regard to hypertension, diabetes mellitus, cigarette smoking and dyslipidemia. However mortality rate was significantly higher in ST segment elevation MI, diastolic dysfunction, restrictive pattern, left ventricular ejection fraction less than 40% and LA volume index ≥32 mL/m2. In multivariate analysis (logistic regression), only LA volume index ≥32 mL/m2 was an independent predictor of increased mortality rate after AMI (P= 0.008).
Conclusion: LA volume index is an independent predictor of poor prognosis in patients with AMI, even after adjustment with clinical predictors and conventional indices of echocardiography.