Aims: 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.
Methods: 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).
Results: 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).
Conclusion: 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.