N -Terminal Pro–Brain Natriuretic Peptide and Other Risk Markers for the Separate Prediction of Mortality and Subsequent Myocardial Infarction in Patients With Unstable Coronary Artery Disease: A Global Utilization of Strategies To Open occluded arteries (GUSTO)-IV Substudy

Abstract

Background— Biochemical markers are useful for prediction of cardiac events in patients with non–ST-segment-elevation acute coronary syndrome (ACS). The associations between N -terminal pro–brain natriuretic peptide (NT-proBNP) and other biochemical and clinical risk indicators, as well as their prognostic value concerning the individual end points of death and myocardial infarction (MI), were elucidated in a large cohort of ACS patients. Methods and Results— NT-proBNP, troponin T, and C-reactive protein (CRP) were analyzed in blood samples obtained at a median of 9.5 hours from symptom onset in 6809 of 7800 ACS patients in the Global Utilization of Strategies To Open occluded arteries-IV (GUSTO-IV) trial. Levels of NT-proBNP were correlated independently with age, female gender, low body weight, diabetes, renal dysfunction, history of MI, heart failure, heart rate, ongoing myocardial damage, and time since onset of ischemia. Increasing quartiles of NT-proBNP were related to short- and long-term mortality that reached 1.8%, 3.9%, 7.7%, and 19.2%, ( P <0.001), respectively, at 1 year. Levels of troponin T, CRP, heart rate, and creatinine clearance, in addition to ST-segment depression, were also correlated independently with 1-year mortality, but NT-proBNP was the marker with the strongest relation. In contrast, only troponin T, creatinine clearance, and ST-segment depression were independently related to future MI. The combination of NT-proBNP and creatinine clearance provided the best prediction, with a 1-year mortality of 25.7% with both markers in the top quartile vs 0.3% with both markers in the bottom quartile. Conclusions— The use of NT-proBNP appears to add critical prognostic insight to the assessment of patients with ACS.