Background: Increased level of N-terminal pro-B type natriuretic peptide (NT-proBNP) is known to be associated with adverse outcome in patients with acute coronary syndrome. We evaluated early outcomes of patients with acute ST-elevated myocardial infarction (STEMI) according to the level of NT-proBNP as a substudy of Korean Acute Myocardial Infarction Registry (KAMIR).
Methods: Study population consisted of 1052 consecutive patients (mean 61.3+/-12.8 years old, male 73.2%) with STEMI of onset <12 h who underwent primary percutaneous coronary intervention (PCI) and who had baseline NT-proBNP level by electrochemiluminescence immnunoassay (ECLIA, NT-proBNP kit, Roche Diagnostics, Mannheim, Germany). The study subjects were divided into two groups according to the level of serum NT-proBNP.
Results: Patients with NT-proBNP level >991 pg/mL (n=329, 57.1% male) had lower left ventricle ejection fraction (LVEF) (47.8+/-11.8% vs. 53.0+/-10.8%, p<0.001), needed longer intensive care (3.7+/-3.6 days vs. 2.8+/-2.4 days, p<0.001) and had higher in-hospital mortality (1.3% vs. 7.4%, p<0.001) than those with NT-proBNP level<or=991 pg/mL (n=723, 80.5% male). Multiple logistic regression analysis revealed that the independent predictors of in-hospital mortality were LVEF<45% (OR 5.43, 95% CI 1.71 to 17.29, p=0.004), elevated NT-proBNP (>991 pg/mL) (OR 3.70, 95% CI 1.14 to 12.03, p=0.030), old age (>or=70 years) (OR 4.71, 95% CI 1.43 to 15.52, p=0.011), advanced Killip class (>1) (OR 4.96, 95% CI 1.58 to 15.53, p=0.006), male gender (OR 5.67, 95% CI 1.45 to 22.21, p=0.013) and TIMI flow 0 before PCI (OR 5.04, 95% CI 1.08 to 23.41, p=0.039).
Conclusions: This study suggests that baseline NT-proBNP level is associated with short term mortality in patients with STEMI underwent primary PCI.