Brain natriuretic peptide in acute myocardial infarction: a marker of cardio-renal interaction.

Abstract

Cardiac and renal functions are major independent predictors of outcomes in both ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI). As B-type natriuretic peptide (BNP) seems to be a major mediator in the cross-talk between heart and kidneys, we aimed at evaluating its capacity to reflect cardiac and renal function in patients with STEMI and NSTEMI. We measured BNP plasma levels at hospital admission in 619 patients with STEMI (n = 346) and NSTEMI (n = 273), grouped according to left ventricular ejection fraction (LVEF; > or ≤40%) and estimated glomerular filtration rate (eGFR; > or ≤ 60 ml/min/1.73 m). Median BNP values were 82 (38-186), 121 (40-342), 219 (80-685), and 474 (124-1263) pg/ml in patients with normal LVEF and eGFR (n = 347), with LVEF 40% or less and eGFR higher than 60 ml/min/1.73 m (n = 120), with LVEF higher than 40% and eGFR 60 ml/min/1.73 m or less (n = 86), and with combined LVEF and eGFR reductions (n = 66), respectively (P < 0.0001). At general linear model, both LVEF higher than 40% (P < 0.0001) and eGFR 60 ml/min/1.73 m or less (P < 0.0001) independently predicted BNP values. At multivariable analysis, BNP, LVEF 40% or less, and eGFR 60 ml/min/1.73 m or less were found to be independent predictors of the combined end point of in-hospital death, cardiogenic shock, need for renal replacement therapy, or mechanical ventilation (P = 0.003; P < 0.0001; P = 0.01, respectively). BNP plasma levels are closely related to LVEF and eGFR at hospital admission, in both STEMI and NSTEMI patients. Future studies should investigate whether BNP levels can summarize in a single parameter the prognostic information provided separately by cardiac and renal dysfunction.