Abstract 17953: The Effect of Early Treatment with Tirofiban on NT-proBNP in Patients with STEMI Undergoing Primary PCI: A Pre-specified Sub-analysis of the On-TIME 2 Trial
Background: Elevated levels of N-terminal-pro-BNP (NT-proBNP) have been associated with poor outcome in patients with ST elevation myocardial infarction (STEMI). We investigated whether early, pre-hospital use of High Dose Bolus Tirofiban (25 microgr/kg) affects the levels of NT-proBNP in patients presenting with STEMI undergoing primary PCI (pPCI). Furthermore we assessed the effect of high NT-proBNP levels on short-term and long-term mortality.
Methods: In On-TIME 2, 984 patients presenting with STEMI were randomized in the ambulance to either high-bolus dose tirofiban or placebo in addition to aspirin (500 mg), heparin (5000 IU), and clopidogrel (600 mg). Blood samples were taken at the time of the pPCI (baseline), 18–24 and 72–96 hours thereafter. The effect on NT-proBNP levels was pre-specified in the statistical plan of the study. NT-proBNP levels were evaluated with two different assay's (A and B) both as a continuous as well as a binary variable, based on the median value. The effect on short-term (30 days) and long-term (1 year) mortality was evaluated based on the median NT-proBNP value.
Results: Patient treated with early, pre-hospital initiation of HBD Tirofiban had a significantly lower NT-proBNP level after pPCI in both assays measured as a continuous variable (A: 1732 ± SD 5019 vs 2114 ± SD 5019; p=0.080; B: 2096 ± SD 3542 vs 1846 ± SD 3004; p=0.041) as well as a binary variable (A: 194/426, 45.5% vs 238/439, 54.2% p=0.011; B: 193/421, 45.8% vs 232/430, 54.0% p=0.018). Those patients with an NT-proBNP level higher than the median value had a significant higher mortality at 30 days (A: 13/427, 3.0% vs 1/426, 0.2% p=0,001; B: 12/420, 2.9% vs 1/419, 0.2% p=0,002) and one year (A: 20/418, 4.8% vs 4/423, 0.9% p=0,001; B: 19/411, 4.6% vs 4/416, 1.0% p=0,001).
Conclusions: Early, pre-hospital treatment of HBD Tirofiban in patients with STEMI significantly reduced the level of NT-proBNP after pPCI. Higher levels of NT-proBNP were strongly related with short and long term mortality.
- © 2010 by American Heart Association, Inc.