PROTECT: ZES not superior to SES in long-term rates of definite, probable stent thrombosis
MUNICH — At 3 years, rates of definite or probable stent thrombosis did not significantly differ between the zotarolimus-eluting stent and the sirolimus-eluting stent. However, after 1 year, the zotarolimus-eluting stent did lead to significantly better rates of definite or probable stent thrombosis.
According to William Wijns, MD, PhD, co-director of the Cardiovascular Center, OLV Hospital, Aalst, Belgium, the PROTECT trial is the largest prospective, randomized, head-to-head drug-eluting stent trial ever presented and is the first powered to compare stent thrombosis with DES. Large pragmatic trials such as PROTECT are essential to determine differential outcomes between DES and to capture the impact of improved procedural and clinical practice on stent thrombosis rates over time, he said at a press conference.
In all, 8,709 real-world patients with single and multiple coronary artery lesions at 196 sites worldwide were randomly assigned 1:1 to the zotarolimus-eluting stent (ZES; Endeavor, Medtronic; n=4,357) or sirolimus-eluting stent (SES; Cypher, Cordis; n=4,352). The primary endpoint was defined as ARC definite/probable stent thrombosis at 3 years; main secondary endpoints were death/large MI, death/MI, cardiac death/large MI and cardiac death/MI. Patients were eligible for the trial if they were aged 18 years or older and underwent elective, unplanned or emergency procedures in native coronary arteries.
Follow-up at 3 years indicated that the primary endpoint did not differ significantly between both arms (ZES, 1.42% vs. SES, 1.79%; P=.224). Researchers reported a trend favoring the ZES in the rate of definite/probable stent thrombosis at 1 year (P=.06). However, when the researchers analyzed the primary endpoint rate after 1 year following the procedure, a statistically significant difference emerged in favor of the ZES (ZES, 0.3% vs. 1.1%; P<.001).
Main secondary endpoints were comparable between both arms at 3 years: death/large MI, ZES 5.4% vs. SES 6.1% (P=.15); death/MI, ZES 7.9% vs. SES 8.7% (P=.23); cardiac death/large MI, ZES 3.8% vs. SES 4.2% (P=.34); and cardiac death/MI, ZES 6.3% vs. SES 6.8% (P=.43).
In regards to dual antiplatelet therapy usage among patients, the researchers reported the following rates: 96% at discharge, 88% at 1 year, 37% at 2 years and 30% at 3 years.
Overall, Wijns said, “There is no difference in definite or probable stent thrombosis rates at 3 years between Endeaver and Cypher. Other clinical safety and efficacy endpoints are also low and were sustained out to 3 years. Time analysis suggests that a difference in stent thrombosis between groups is emerging over time, emphasizing the importance of continued follow-up.” – by Brian Ellis
For more information:
Wijns W. Hot line II: Late breaking trials on interventions. Presented at: the European Society of Cardiology Congress; Aug. 25-29, 2012; Munich.
Disclosure: Dr. Wijns receives consulting fees to the institution and reports contracted research between the Cardiovascular Research Center Aalst and several pharmaceutical and device companies. The trial was sponsored by Medtronic.