N-Terminal Pro-BNP in Acute Coronary Syndrome Patients with ST Elevation versus Non ST Elevation Myocardial Infarction

The study aimed to evaluate the differences in secretion of NT-proBNP and conventional cardiac markers in patients with STE-ACS vs NSTE-ACS as a trial to solve the dilemma of the early detection of myocardial ischemia in NSTE-ACS. Sixty two patients with acute coronary syndrome (ACS) divided into 2 groups according to ECG: group 1 with elevated ST segment in ECG (STE-ACS) and group 2 with non elevated ST segment (NSTE-ACS). Twenty healthy subjects with matched age and sex were enrolled as control group in this study. In the sera of all subjects, levels of NT-proBNP, CK-MB and troponin-T were measured by different kits. CK-MB and TnT were both significantly higher in STE-ACS patients compared to NSTE-ACS patients. Conversely, NT-proBNP was significantly higher in NSTE-ACS patients than STE-ACS especially within 4 hours from onset of chest pain. Comparison between NT-proBNP, TnT and CK-MB levels by ROC curves revealed area under the curves = 0.68, 0.31, 0.17 respectively. NT-proBNP at cutoff 415 pg/mL in NSTE-ACS patients had higher sensitivity and specificity (92%, 39%; respectively) than other markers that will help in early diagnosis of NSTE-ACS.