Three Months of DAPT With Endeavor Stent Safe as Conventional DAPT: RESET

March 24, 2012

March 24, 2012 (Chicago, Illinois) — Selected patients treated with the zotarolimus-eluting Endeavor (Medtronic) stent can discontinue dual antiplatelet therapy (DAPT) three months following PCI, with some caveats, according to a new study presented today. Treatment with aspirin and thienopyridine therapy for three months with the Endeavor stent was noninferior to standard 12-month DAPT in patients treated with other drug-eluting stents (DES) in terms of the primary end point, a composite of death from cardiovascular causes, MI, stent thrombosis, target vessel revascularization (TVR), or bleeding at one year.

"Because patients with very high risk were not included, the generalized application of these results to the entire population demands careful attention," Dr Myeong-Ki Hong (Yonsei University College of Medicine, Seoul, Korea) told the audience during a featured interventional session at the American College of Cardiology (ACC) 2012 Scientific Sessions. That said, the results could have potential implications for the treatment of selected populations.

"In the aspect of clinical implications, as an alternative PCI strategy, the Endeavor stent plus three months of dual antiplatelet therapy might be useful in patients at risk of bleeding complications; those at risk of poor compliance with the medication, especially elderly patients; those with a high probability of unexpected noncardiac surgery or invasive procedures; and finally those with a low risk of stent thrombosis," said Hong.

In 2011, an analysis of patients treated with the Endeavor stent suggested there was no increased risk of death, MI, stroke, or stent thrombosis in stopping DAPT at six months. At the time, Dr David Kandzari (Piedmont Heart Institute, Atlanta, GA) told heartwire that abbreviated DAPT may be safe and that inability to comply with 12 months of DAPT should not be considered an absolute contraindication to PCI with DES.

Extrapolating the RESET Results to Other Patients

In the RESET trial, as the study is known, Hong and colleagues included patients with stable angina, unstable angina, or acute MI undergoing elective PCI. Patients with in-stent restenotic lesions, chronic total occlusions, or significant left main disease were excluded from the trial, as were patients with acute ST-segment elevation MI (STEMI). In total, 2148 patients were enrolled, with 1059 randomized to the Endeavor stent and three months of DAPT and 1058 patients treated with standard 12-month DAPT and other DES.

At 12 months, the combined end point of cardiovascular death, MI, stent thrombosis, TVR, or bleeding occurred in 4.7% of patients in both treatment arms (p<0.01 for noninferiority). The clinical end point of any death, MI, or stent thrombosis also did not differ significantly between those randomized to Endeavor and three months of DAPT and those randomized to standard stent therapy. Overall, there was no significant difference in any of the individual components of the primary end point. Stent thrombosis occurred in two patients treated with the Endeavor stent, but both cases occurred within the first month. Three patients had a stent thrombosis in the conventional-therapy arm, with all three cases occurring between three and 12 months.

There was no significant difference in the primary end point in any of the subgroups, including patients with diabetes mellitus and those with acute MI.

Speaking during session, Dr Antonio Columbo (Columbus Hospital, Milan, Italy) said that studies from Asia have reported rates of stent thrombosis that are half of what is typically reported in North American and European studies. "I believe it's not easy to translate these conclusions to other populations," said Columbo of the RESET results. "I think some genetic or other factors may play a role in these low thrombosis rates."

To heartwire , Dr Ted Feldman (NorthShore University HealthSystem, Evanston, IL), another panel member, said the ability to extrapolate these results to other populations is further complicated by the fact that the Endeavor stent has largely been replaced by the Resolute stent, a next-generation zotarolimus-eluting stent also made by Medtronic. Just last month, the Food and Drug Administration approved the Resolute Integrity zotarolimus-eluting stent, which is, as reported by heartwire , similar to the Resolute but uses a different platform to improve delivery.

Regarding the RESET study, Hong added his own limitations, namely that one year might not be long enough to detect potential differences in late and very late outcomes, such as very late stent thrombosis. Also, he noted that patients in the comparator arm were not treated with one type of DES, making the comparisons between study arms more difficult.

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