Tintu Thomas, Sibi N. S
BACKGROUND
This study was conducted to determine the usefulness of sodium levels in predicting the mortality and morbidity following acute myocardial infarction.
MATERIALS AND METHODS
Institutional ethics committee approved the study and 177 consenting patients satisfying the inclusion criteria were enrolled. History, demographic, clinical, biochemical, echocardiographic and ECG findings were recorded in semi structured questionnaire. Plasma sodium levels were estimated during admission. Parameters of outcome were death, heart failure, reinfarction, stroke, and arrhythmia which were followed up clinically and by echocardiogram. Data analysis was done by SPSS®. Tests of significance and bivariate logistic regression analysis were done to find out relationship between hyponatraemia and mortality and also the factors which are strongly correlated for the development of hyponatraemia.
RESULTS
Mean age of the study participants was 52.8 years and was predominantly composed of males. Statistically significant mortality was noticed in hyponatraemia (23.3%) when compared with participants with normal sodium levels (12.1%) (OR-2.2; 95% CI 1 - 4.9). Diabetes was more common in hyponatraemia (68.6%) and 49.5% were diabetic among participants with normal sodium levels (OR-2.2; 95% CI 1.2 -4.1). Hypertension was more common in hyponatraemia (60.5%) and 22% were hypertensive among participants with normal sodium levels (OR-5.4; 95% CI 2.8 -10.5). Heart failure was more common among participants with hyponatraemia when compared to those with normal sodium levels (39.5% versus 23%) (OR-2.2; 95% CI 1.1 - 4.2). Ejection fraction <45% was more common in participants with hyponatraemia (53.5%) and in participants without hyponatraemia (15.4%) (OR-6.4; 95% CI 3.1-12.9). Of the 54 participants who had anterior wall myocardial infarction, 41.9% had hyponatraemia on admission and 19.8% having normal sodium levels (OR-2.9; 95% CI 1.5-5.7).
CONCLUSION
The presence of hyponatraemia during admission for acute myocardial infarction is a strong predictor of mortality and heart failure after 60 days of follow up. hyponatraemia is strongly correlated with male sex, diabetes mellitus, hypertension, anterior myocardial infarction.
