Aims: No studies have yet been conducted concerning plasma N-terminal pro-brain natriuretic peptide (Nt-pro-BNP) levels after Myocardial Infarction (MI) and their relationship with short-term outcomes in diabetic patients.
Methods and results: Five hundred and sixty patients hospitalized for MI from the RICO survey, including 199 diabetic and 361 non-diabetic subjects, were included in the study. Plasma Nt-pro-BNP levels were measured on admission. Median Nt-pro-BNP levels were significantly higher in diabetic patients compared with non-diabetic patients [245 (81-77) vs. 130 (49-199) pmol/L, P<0.0001]. This difference remained highly significant after adjustment for age, female gender, creatinine clearance, left ventricular ejection fraction (LVEF), plasma peak troponin, anterior wall necrosis, and hypertension. In multivariable analysis, Nt-pro-BNP levels were negatively associated with creatinine clearance (P<0.0001) and LVEF (P<0.0001) and positively associated with plasma peak troponin (P<0.0001), age (P=0.0029), diabetes (P=0.0031), and female gender (P=0.0102). Diabetic patients showed a 4.7-fold increase in hospital mortality (15.6 vs. 3.3%, P<0.0001) and a 2.2-fold increase in cardiogenic shock (17.6 vs. 7.7%, P=0.0004). In multivariable analysis, diabetes was an independent factor for mortality [OR: 1.79 (1.45-2.20); P=0.0064] and cardiogenic shock [OR: 1.45 (1.22-1.72); P=0.0364] when the variable Nt-pro-BNP level was not introduced into the model, but was less significantly associated with mortality [OR: 1.73 (1.39-2.16); P=0.0107] and no longer associated with cardiogenic shock when Nt-pro-BNP was in the model.
Conclusion: After MI, diabetes is independently associated with high plasma Nt-pro-BNP levels. This elevated Nt-pro-BNP is strongly associated with the increased incidence of in-hospital mortality and cardiogenic shock observed in diabetes. Our findings clearly indicate that plasma Nt-pro-BNP provides highly valuable prognostic information on in-hospital outcome after MI, in particular in diabetic patients.