Impact of age on the predictive value of NT-proBNP in patients with diabetes mellitus stabilised after an acute coronary syndrome

Aims To assess the impact of age on the prognostic value of NT-proBNP concentration in patients with type-2 diabetes mellitus (T2DM) stabilised after an Acute Coronary Syndrome (ACS). Methods The AleCardio study compared aleglitazar with placebo in 7226 patients with T2DM and recent ACS. Patients with heart failure were excluded. Median follow-up was 104 weeks. Baseline NT-proBNP plasma concentration was measured centrally. Multivariable Cox regression was used to determine the mortality predictive information provided by NT-proBNP across age groups. Results Median age was 61y (IQR 54, 67). NT-proBNP concentration increased by quartile (Q) of age (median 264, 318, 391, and 588 pg/ml). Compared to Q1, patients in Q4 of NT-proBNP had higher (p < 0.001) adjusted HR for all-cause (aHR 6.9; 95 % CI 4.0–12) and cardiovascular (11; 5.4–23) death. Within each age Q, baseline NT-proBNP in patients who died was 3 times higher than in survivors (all p < 0.001). When age and NT-proBNP levels were modeled as continuous variables, their interaction term was nonsignificant. The relative prognostic information provided by NT-proBNP (percent of total X 2 ) increased from 38 % in age Q1 to 75 % in age Q4 for mortality, and from 50 % to 88 % for CV death. Conclusions Among patients with T2DM stabilised after an ACS, NT-proBNP level predicts death irrespective of age.