Correlation between NT-pro BNP levels and early mitral annulus velocity (E') in patients with non-ST-segment elevation acute coronary syndrome

Acute coronary syndromes in the absence of ST-segment elevation (NSTE-ACS) are a heterogeneous entity in which early risk stratification is essential. Diastolic dysfunction is precocious and associated with poor prognosis. BNP has been recognized as a biochemical marker of ventricular dysfunction and ischemia. Objective: To investigate if there is correlation of NT pro-BNP levels with diastolic dysfunction in patients with NSTE-ACS. Methods: Fifty-two patients with NSTE-ACS admitted to the coronary unit were included. NT-pro brain natriuretic hormone (BNP) levels and a Doppler echocardiogram were obtained in all and systolic and diastolic functions were analyzed. Their Doppler indexes were compared with those of 53 age-and sex-matched controls, without heart failure symptoms and with normal ejection fraction (EF) and normal NT-pro BNP levels. Results: Twenty-four patients (46%) with unstable angina and 28 patients (54%) with acute myocardial infarction (AMI) were included. Mean EF was 55.9 +/- 10.7% and mean NT- pro BNP level was 835 +/- 989 pg/ml. No mitral or pulmonary venous flow parameters of diastolic function correlated with NT-pro BNP levels. E'/A' correlated with NT-pro BNP level in univariate analysis but, in a multivariate analysis, only the EF and the E' showed negative correlation with the peptide level (r = -0.33, P = 0.024 and r = -0.29, P = 0.045, respectively). Thirteen patients presented with stage II diastolic dysfunction but the NT-pro BNP level in these patients did not differ from the level in stage I patients. Conclusion: NT- pro BNP levels are elevated in acute coronary syndromes, even in the absence of significant necrosis. Of all echocardiographic parameters investigated, only E' and the EF correlated with the levels of NT-pro BNP in this group of patients.