Abstract 2061: Prognostic Value of NT-proBNP Assessment at Admission in Patients with Acute Coronary Syndromes who are Troponin T Negative
Purpose Recently BNP and NT-proBNP have been found to be highly predictive for an adverse outcome in patients with acute coronary syndromes (ACS). However, the prognostic value of NT-proBNP at admission in patients without troponin elevation at admission is unclear. Therefore, we analysed the prognostic value of NT-proBNP assessed from patients presenting with the entire spectrum of acute coronary syndromes who were troponin negative in comparison to troponin positive patients.
Methods We included 1131 consecutive patients (342 females, age 64 ± 12 years) from April 2003 till March 2005 who were referred for primary PCI (STEMI, n=488) or early invasive diagnostic (NSTE-ACS, n=643) within 48 hours after the index event. Follow up data after 6 months were available for 1057 patients (94%).
Results A subgroup of 343 (30%) patients were troponin T (TnT) negative (<0.03 ng/ml) at admission. There was no difference in gender distribution, age and creatinine between TnT negative and positive patients. However, time delay from onset of symptoms until admission was longer in TnT positive patients (8.5 (4.4 –15.5) hours vs. 3.9 (2.3– 8.9) hours; p<0.001). NT-proBNP values at admission were lower in TnT negative patients 159 (64 – 474) pg/ml vs. 839 (257–2308) pg/ml; p<0.001. In the entire population 54 patients died, 13 (3.8%) in the TnT negative group and 41 (5.2%) in the TnT positive group. The AUC of the ROC curve for NT-proBNP as a predictor for death in the TnT negative subgroup was 0.785; p=0.001. Applying an optimized cut-off value of 637 pg/ml derived from the ROC analyses NT-proBNP yielded a specificity of 81%, a sensitivity of 69%, a NPV of 99% but a PPV of 13%. In Log Rank test NT-proBNP was highly discriminative to predict mortality (Log Rank 19.6; p<0.001).
Conclusion: Our data shows that NT-proBNP assessed at admission provides important prognostic information in patients with acute coronary syndromes who are troponin T negative. Thus, NT-proBNP assessment in ACS patients should be considered in clinical routine.