A comparison of NT-proBNP and albuminuria for predicting cardiac events in patients with diabetes mellitus.

AIMS Cardiovascular events are the most relevant events in patients with diabetes mellitus. We aimed to compare the predictive values of N-terminal pro-brain natriuretic peptide (NT-proBNP) and the state-of-the-art marker, albuminuria, for cardiac events in diabetic patients. METHODS In this prospective observational study we recruited 1071 patients with diabetes mellitus. NT-proBNP and albuminuria ⊟ defined as a urinary albumin/creatinine ratio >30 mg/g were measured at baseline. Patients were followed during a mean observation period of 33.1 months. A total of 103 patients reached the defined endpoint (unplanned hospitalization due to a cardiac event or death). RESULTS The mean duration of diabetes was 15 ± 12 years and the mean HbA(1c) was 7.5 ± 3.1%. At baseline, 23.7% of the patients presented with albuminuria and 36.6% had plasma NT-proBNP values >125 pg/ml. Multiple Cox regression analysis including age, gender, duration of diabetes HbA(1c), albuminuria, and lnNT-proBNP revealed that lnNT-proBNP (hazard ratio 2.314; 95% CI 1.914-2.798, p < 0.001) was a better predictor than albuminuria (HR 1.544; 95% CI 1.007-2.368, p = 0.047) or age (HR 1.030; 95% CI 1.008-1.053, p = 0.007). Calculating different Cox-models with (A) albuminuria, (B) NT-proBNP, or (C) both in the model revealed that the C-index was best if NT-proBNP was entered in the model (C-index for A 0.735, for B 0.809, and for C 0.786). Kaplan-Meier analysis demonstrated that albuminuria does not add substantial information if NT-proBNP is entered into the model. CONCLUSION NT-proBNP was superior to albuminuria for predicting cardiac events.