B-type natriuretic peptide and assessment of jeopardised myocardium in acute myocardial infarction

Background B-type natriuretic peptide (BNP) is used as prognostic marker in acute coronary syndromes. It is unknown whether BNP reflects the amount of jeopardised myocardium in the initial phase of acute ST-elevation myocardial infarction (STEMI). Methods Patients admitted for percutaneous coronary intervention in the acute phase of STEMI were studied. Samples for BNP were taken at the time of coronary intervention and were correlated with the amount of jeopardised myocardium. This was defined on coronary angiography as the vascular region distal to the infarct-related lesion and was expressed by a vascular score. The extend of epicardial injury on ECG was evaluated by: summation of STsegment elevation in the infarct-related leads, number of leads with ≥ 1 mm ST-segment elevation and number of leads with ≥ 1 mm ST-segment depression/elevation. Results A total of 113 patients (median age (25th, 75th percentile) 61 (54, 69)) were studied. Median BNP was 27 pg/ml (12, 62) and was assessed 225 min (150, 315) after onset of pain. There was no significant relation between BNP and vascular score (r = 0.026, p = 0.8). The only independent variable of BNP was time delay between onset of pain and sample collection. Stepwise regression identified the extent of ST-segment elevation as independent predictor of the vascular score. Conclusion At initial presentation of STEMI, BNP measurement does not allow a correct prediction of jeopardised myocardium. In contrast, ST-segment analysis, in particularly the extent of ST-segment elevation, provides useful information about the extent of jeopardised myocardium.