September 19, 2014 — The largest prospective longitudinal study of acute myocardial infarction (MI) patients offers unique insight into the use, safety and effectiveness of blood thinners prasugrel and clopidogrel in hospitals across the United States. Findings were reported Sept. 15 at the 2014 Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium.
Although randomized clinical trials have established the efficacy of prasugrel in acute MI patients, limited data is available on the comparative effectiveness and safety of prasugrel vs. clopidogrel therapy when used in routine clinical practice in the United States.
The TRANSLATE-ACS trial is a multicenter, prospective, observational study that compared prasugrel and clopidogrel among myocardial infarction (MI) patients undergoing percutaneous coronary intervention (PCI). Primary endpoints were a composite of major adverse coronary events (MACE: all-cause death, MI, stroke or unplanned coronary revascularization), stent thrombosis, as well as GUSTO moderate to severe bleeding at one year follow-up.
The trial observed physician-directed patterns of prasugrel vs. clopidogrel use among 11,969 patients treated with PCI at 233 hospitals in the United States. Prasugrel was used in 3,123 MI patients (25.5 percent) at the time of PCI. Patients treated with prasugrel were younger (median 57 vs. 61 years, p<0.0001), more likely to present with ST elevated myocardial infarction (STEMI, the most serious form of a heart attack), and less likely to have prior MI (14.6 percent vs. 21.3 percent, <0.0001) or diabetes (24.6 percent vs. 27.2 percent, p= 0.003) than clopidogrel-treated patients.
While unadjusted comparisons demonstrated lower MACE in patients receiving prasugrel vs. clopidogrel, these differences were no longer significant after risk adjustment (Adj. HR=1.03, 95% CI, 0.92 – 1.16, p=0.59). However prasugrel was associated with significantly lower adjusted risk of definite stent thrombosis per ARC criteria. (0.97 percent vs. 1.24 percent, p=0.11; Adj. HR 0.54 (0.33-0.89), p=0.02). Among all-comers, prasugrel was also associated with significantly higher adjusted bleeding risk relative to clopidogrel (Adj. HR=1.30, 95% CI, 1.04-1.63, p=0.02). In propensity matched secondary analyses, the associations with MACE and stent thrombosis showed consistent results, whereas the association with bleeding was no longer statistically significant.
“TRANSLATE-ACS represents the largest prospective longitudinal study of acute MI patients undergoing PCI in contemporary community practice in the United States.” said lead investigator Tracy Y. Wang, M.D., MHS, MS. Wang is an associate professor of Medicine at Duke University. “This observational study found that patients treated with prasugrel vs. clopidogrel significantly differ, and the trial provided a unique opportunity to compare their effectiveness and safety in the real world.”
The TRANSLATE-ACS trial was funded by Lilly USA and Daiichi Sankyo. Wang reported research grant support to the Duke Clinical Research Institute from Daiichi Sankyo, Eli Lilly, Astra Zeneca, Gilead Sciences and Glaxo Smith Kline.
For more information: www.crf.org, www.tctconference.com