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A second-generation everolimus-eluting stent (EES) is noninferior to a first-generation sirolimus-eluting stent (SES) for treating acute myocardial infarction (MI), according to randomized data published in the July 31, 2012, issue of the Journal of the American College of Cardiology. Moreover, at 1 year stent thrombosis rates were low and similar between the 2 devices, though longer follow-up is needed, the authors say.

For the all-comer, multicenter XAMI (Xience V stent vs. Cypher stent in primary PCI for Acute Myocardial Infarction) trial, Sjoerd H. Hofma, MD, PhD, of the Medical Center Leeuwarden (Leeuwarden, The Netherlands), randomized 625 patients with acute MI in a 2:1 ratio to EES (Xience V; Abbott Vascular, Santa Clara, CA; n = 404) or SES (Cypher; Cordis, Miami Lakes, FL; n = 221).

EES Appear to Reduce MACE

At 1 year, EES met the criteria for noninferiority to SES, showing an absolute 3.7% reduction in MACE (cardiac death, nonfatal MI, and TVR), the primary endpoint (RR 0.52; 95% CI 0.27-1.00; P = 0.048). There were no differences in rates of cardiac death, TVR, or Academic Research Consortium-defined definite or probable stent thrombosis (table 1).

Table 1. One-Year Clinical Results: EES vs. SES

The MACE benefit seen with EES remained when the 4% of patients who had non-STEMI were excluded (3.5% vs. 7.6% for SES; P = 0.027).

The suggestion of a stent thrombosis benefit with EES at 1 year was largely attributable to an early difference between the devices (0.7 vs. 2.3 for SES; P = 0.14); the incidence between 30 days and 1 year was identical between the groups (0.5%).

Assumption Confirmed

Dr. Hofma told TCTMD in an e-mail communication that these data confirm results of several recent meta-analyses indicating superiority of the second-generation DES. He added that use of DES in general in acute MI patients has been growing recently, thanks to increasing evidence for their safety and efficacy in that setting.

The advantage of EES over SES is due in part to “a less pronounced endothelial dysfunction in the months after stenting,” Dr. Hofma said, adding that histological studies have shown faster endothelial regrowth inside the stented segment. “These effects could also partly be the result of a newer and more hemocompatible and biocompatible coating used in the Xience stents.”

In a telephone interview with TCTMD, Ajay J. Kirtane, MD, SM, of Columbia University Medical Center (New York, NY), said, “The fact that [Xience V] is a noninferior stent is something that I think most people have already assumed, but it’s nice to have randomized trial data confirming that.”

Dr. Kirtane added that the low rates of stent thrombosis are encouraging, though this study was not powered to detect differences in adverse events. The study authors note that XAMI has a planned follow-up of 3 years, which could yield differences in very late stent thrombosis.

The new results also provide reassurance regarding the use of DES in acute MI, Dr. Kirtane commented. “Based upon these data, it looks like restenosis rates are very low, and there doesn’t appear to be an adverse safety profile associated with the use of DES,” he said. “In terms of using DES vs. bare metal stents, I think [that decision] will ultimately be based on lesion or patient characteristics. But there certainly doesn’t appear to be an adverse safety signal.”

Study Details

About three quarters of patients in each group were men, and the average age was approximately 62 years. There were no differences between the groups with regard to smoking status, diabetes, hypertension, family history of cardiovascular disease, and renal failure. Median time from first medical contact to balloon inflation was 75 minutes for both arms.

More patients in the SES group had heavily calcified lesions (11.0% vs. 5.7%; P = 0.02), but there were no other differences with regard to angiographic or procedural characteristics.

 

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Source:
Hofma SH, Brouwer J, Velders MA, et al. Second-generation everolimus-eluting stents versus first-generation sirolimus-eluting stents in acute myocardial infarction: 1-year results of the randomized XAMI (Xience V stent vs. Cypher stent in primary PCI for Acute Myocardial Infarction) trial. J Am Coll Cardol. 2012;60;381-387.

 

 

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• CIBELES: Xience Stands Up to Cypher for CTO PCI

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