Continued thienopyridine therapy after EES reduces thrombosis, MI

SAN FRANCISCO — In a post hoc analysis of the Dual Antiplatelet Therapy study, patients treated with an everolimus-eluting stent who continued thienopyridine plus aspirin beyond 1 year had reduced stent thrombosis and MI compared with aspirin alone but increased bleeding.

“The relative increase in mortality among [everolimus-eluting stent]-treated patients receiving continued thienopyridine therapy (vs. placebo) appears to mirror the observation on mortality for the overall DAPT [drug-eluting stent] subset,” according to the researchers.

James B. Hermiller, MD, FACC, of the St. Vincent Heart Center in Indianapolis, and colleagues analyzed 9,961 patients with coronary stenting (4,703 with everolimus-eluting stent [EES]) of 25,682 patients with coronary stenting (11,308 with EES) enrolled in the DAPT study.

Patients in the cohort — deemed eligible to continue aspirin after 12 months of thienopyridine plus aspirin — were then randomly assigned to 18 more months of thienopyridine or placebo.

In the DAPT study, extended thienopyridine plus aspirin led to a decrease in ischemic events, with low rates of stent thrombosis and MI observed in patients treated with DES. In the current investigation, the investigators assessed outcomes with EES for 12 to 30 months.

In patients treated with EES, continuing thienopyridine lowered stent thrombosis compared with placebo (0.3% vs. 0.7%; HR= 0.38; 95% CI, 0.15-0.97) and MI (2.1% vs. 3.2%; HR = 0.63; 95% CI, 0.44-0.91).

However, the treatment did not decrease a composite of death, MI and stroke compared with placebo (4.3% vs. 4.5%; HR = 0.89; 95% CI, 0.67-1.18). Further, thienopyridine increased both moderate/severe bleeding (2.5% vs. 1.3%; HR = 1.79; 95% CI, 1.15-2.8) and death (2.2% vs. 1.1%; HR = 1.8; 95% CI, 1.11-2.92); death due to cancer, unrelated to bleeding, also rose (0.64% vs. 0.17%, P = .01)

“This study contributes to the growing body of evidence regarding prevention of stent thrombosis and [MI] after coronary stenting with continued [DAPT], as well as the risks of increased bleeding,” according to the researchers. “Additional research is needed to further individualize therapy to optimize patient selection for continued thienopyridine therapy.” – by Allegra Tiver

References:

Hermiller et al. DAPT: A prospective, double blind, placebo-controlled randomized trial of 1-year versus 2.5 years of dual antiplatelet therapy (everolimus-eluting stent-treated subset). Presented at: TCT 2015; Oct. 11-15, 2015; San Francisco.

Hermiller JB, et al. JACC Cardiovasc Interv. 2015;doi:10.1016/j.jcin.2015.10.001.

Disclosure: Hermiller reports consulting for Abbott Vascular, Boston Scientific, Medtronic and St. Jude Medical. Please see the full study for a list of all other authors’ relevant financial disclosures.