Real-World Equivalence Seen for Zotarolimus- and Everolimus-Eluting Stents

 
Second-generation stents that release either zotarolimus or everolimus have proven equally safe and effective in a large Korean registry study. Despite the fact that three-quarters of patients were treated for an off-label indication, rates of target lesion failure (TLF) and stent thrombosis were low, according to a paper published online December 26, 2012, ahead of print in the Journal of the American College of Cardiology.   

Hyo-Soo Kim, MD, PhD, of Seoul National University Hospital (Seoul, South Korea), analyzed data from the EXCELLENT (Efficacy of Xience/Promus Versus Cypher to Reduce Late Loss After Stenting) and RESOLUTE-Korea registries on 3,056 patients treated with Xience V/Promus everolimus-eluting stents (EES; Abbott Vascular, Boston Scientific) and 1,998 patients who received Endeavor Resolute zotarolimus-eluting stents (ZES; Medtronic, Minneapolis, MN). In all, 75.6% of the cohort had at least 1 off-label indication.

Off-Label Use Associated with Poorer Outcome

At 1 year, crude rates of TLF (primary endpoint; composite of cardiac death, target vessel MI, or clinically indicated TLR) were similar at 2.7% for EES and 2.9% for ZES (P = 0.662). Results for the patient-oriented composite outcome, which included all-cause mortality, any MI, and any revascularization, also were equivalent at 7.4% and 7.7%, respectively (P = 0.702).

Stent thrombosis was rare, with a total of 25 definite or probable cases (0.5%) occurring without between-group differences. Most patients remained on dual antiplatelet therapy at 6 months (96.8%) and at 1 year (84.8%).

A propensity score-matched analysis of 1,014 pairs, intended to balance differences in baseline characteristics between the EES and ZES groups, also showed comparable results for TLF and the patient-oriented composite. Definite or probable stent thrombosis rates remained similar at 0.6% for EES and 0.2% for EES at 1-year-follow-up (P = 0.288).

On multivariable analysis in the matched pairs, off-label indication was the strongest predictor of TLF (HR 2.882; 95% CI 1.226-6.779; P = 0.015). Other predictors were chronic renal failure (HR 2.774; 95% CI 1.166-6.603; P = 0.021), diabetes (HR 1.957; 95% CI 1.128-3.396; P = 0.043), and higher age (HR 1.051; 95% CI 1.022-1.081; P = 0.001).

Subgroup analyses suggested that EES might produce worse outcomes than ZES in patients undergoing multivessel PCI or in lesions measuring 28 mm or longer.

Capturing Routine Practice

“Both stents had comparable outcomes [at] 1 year, with low event rates, suggesting their excellent safety and efficacy in real-world practice,” Dr. Kim and colleagues conclude.

Stent thrombosis was especially infrequent “considering the complexity of the lesions treated,” they note, adding that the similarity between the 2 devices for this endpoint stands in contrast to previous randomized studies. “Although well-designed large [randomized controlled trials] usually have high internal validity, their subjects and protocols often are not generalizable to routine practice. Conversely, prospective registries have the strengths of a broader patient population and reflection of routine clinical practices.”

Study Details

Patients and lesions tended to be high-risk. In the all-comers population, 72.5% and 80.7% of the EES and ZES groups, respectively, were treated off label (P < 0.001). Numerous baseline differences existed.



Source:
Park KW, Lee JM, Kang S-H, et al. Safety and efficacy of second-generation everolimus-eluting Xience V stents versus zotarolimus-eluting Resolute stents in real-world practice: Patient-related and stent-related outcomes from the multicenter prospective EXCELLENT and RESOLUTE-Korea registries. J Am Coll Cardiol. 2012;Epub ahead of print.

Disclosures:
  • Dr. Kim reports receiving research grants, lecture fees, and honoraria from Abbott Vascular, Boston Scientific, and Medtronic.

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