PROTECT: ZES Sustain Lead Over SES at 5 Years

BARCELONA, Spain—At 5 years, zotarolimus-eluting stents (ZES) continue to reduce the risk of stent thrombosis and death/MI compared with sirolimus-eluting stents (SES), according to the latest data from the PROTECT trial presented September 2, 2014, at the European Society of Cardiology Congress. The differences emerged only after 3 years of follow-up.

At 5 years, the risk of definite/probable stent thrombosis (primary endpoint) was lower for the ZES group as were those of death/MI and cardiac death/MI (table 1).

Table 1. Five-Year Outcomes

 

The differences in death/MI were mainly driven by a reduction in late, spontaneous Q-wave MI, Dr. Camenzind said. “Higher incidence of stent thrombosis and death/MI with [SES] appeared very late after DAPT adherence decreased,” he noted, even though adherence was still “relatively high” at 5 years. “The reliable assessment of the safety and efficacy of any implanted device such as a stent/scaffold requires well-powered and long-term studies.”

Longer Follow-Up Key to Comparative Effectiveness

Discussant Roxana Mehran, MD, of Mount Sinai Medical Center (New York, NY), noted that PROTECT is the largest ever head-to-head stent trial powered for hard endpoints, in particular the “very important endpoint of stent thrombosis.” With few exclusion criteria, she said, the study closely resembles real-world use.

Yet Cypher is a first-generation device, while Endeavor “is also considered [to be] in the early generation of drug-eluting stents. They have completely different stent geometry. The material is different, with stainless steel for Cypher and a cobalt alloy for Endeavor. The polymer is different, as is the drug,” she noted, making it difficult to tease out exactly what is leading to disparate levels of stent thrombosis.

Between 3 and 5 years, Dr. Mehran commented, “a lot of the action occurred.”

Interestingly, a substantial number of patients remained on DAPT well after the recommended duration of 12 months, she noted. “Why was that?... Was it good tolerance and adherence to DAPT? So leave them on it because they’re doing great? Or was it something about the patients that kept them on DAPT? Or was it just a physician who felt nervous about all the news that was out there about first-generation DES?”

Dr. Mehran noted that the 3-to-5-year time frame can say more about comparative effectiveness than the initial years after treatment.

“This pathobiologically driven time frame will become an issue—a dismay—for us, because we always want very fast completion of our trials,” she observed. “This trial highlights the importance of well-powered and long-term studies for assessment of safety and efficacy of devices, but the trade off … is that by completion [of such studies] the results may not be relevant to clinical practice, because our field in interventional cardiology is moving so much faster than these trials.”

The most pressing issue to investigate going forward, she said, is the optimal duration of DAPT.

 

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Source: 
Camenzind E. Final five-year results from the randomized drug-eluting stent trial PROTECT: the Patient-Related Outcomes wiTH Endeavor vs Cypher stenting Trial. Presented at: European Society of Cardiology Congress; September 2, 2014; Barcelona, Spain.

Related Stories:

• PROTECT: Lower Stent Thrombosis Risk with Endeavor Emerges at 4 Years
• Stent Thrombosis Surprise: Rates Low, Similar for Endeavor and Cypher at 3 Years
• PROTECT: ZES Lowers Thrombosis Rates Over SES at 4 Years