Lancet: Prasugrel reduces risk of in-stent thrombosis better than Plavix
Intensive antiplatelet therapy with prasugrel (Effient) resulted in fewer ischemic outcomes, including stent thrombosis than with standard clopidogrel (Plavix), according to results of the study published in the April 19 issue of the Lancet.

Stephen D. Wiviott, MD, from the cardiovascular division at Brigham and Women's Hospital and Harvard Medical School in Boston, and colleagues assessed the rate, outcomes and prevention of ischemic events in patients treated with prasugrel or clopidogrel with stents in the TRITON–TIMI 38 trial. The trial showed that prasugrel can reduce ischemic events compared with standard clopidogrel therapy, the authors noted.

The researchers included patients with moderate-risk to high-risk acute coronary syndromes (ACS) in the analysis if they had received at least one coronary stent at the time of the index procedure following randomization in TRITON-TIMI 38, and were further subdivided by type of stent received.

The investigators said the patients were randomly assigned in a 1 to 1 fashion to receive a loading dose of study drug (prasugrel 60 mg or clopidogrel 300 mg) immediately after randomization, followed by daily maintenance therapy (prasugrel 10 mg or clopidogrel 75 mg). All patients were to receive aspirin therapy. Treatment was to be continued for a minimum of six months and a maximum of 15 months.

The primary endpoint was the composite of cardiovascular death, non-fatal MI or non-fatal stroke, according to researchers. They also assessed stent thrombosis using Academic Research Consortium definitions.

The investigators said 12,844 patients received at least one coronary stent; 5,743 received only drug-eluting stents, and 6,461 received only bare-metal stents.

Wiviott and colleagues found that prasugrel compared with clopidogrel reduced the primary endpoint (9.7 vs. 11.9 percent) in the stented cohort, in patients with only drug-eluting stents (9 vs. 11.1 percent), and in patients with only bare-metal stents (10 vs. 12.2 percent).

The researchers said that stent thrombosis was associated with death or MI in 89 percent (186/210) of patients. The authors noted that stent thrombosis was reduced with prasugrel overall (1.13 vs. 2.35 percent), in patients with drug-eluting stents only (0.84 vs. 2.31 percent) and in those with bare-metal stents only (1.27 vs. 2.41 percent).

Wiviott and colleagues noted that the “findings are statistically robust irrespective of stent type, and the data affirm the importance of intensive platelet inhibition in patients with intracoronary stents.”

Daiichi Sankyo and Eli Lilly supported the TRITON–TIMI 38 trial with research grants.