EXAMINATION Data Show Superiority of EES vs BMS at 5 Years

September 3, 2015—The European Society of Cardiology (ESC) announced that findings from the EXAMINATION trial demonstrated the superiority of a second-generation everolimus-eluting stent (EES) over a bare-metal stent (BMS) at 5 years. The data were presented at the ESC Congress 2015, held August 29 to September 2 in London, United Kingdom.

According to ESC, the multicenter, multinational, prospective, randomized, single-blind, controlled EXAMINATION trial compared the performance of EES versus BMS in an all-comer ST-segment elevation myocardial infarction (STEMI) population. The ESC noted that, until now, no data have been available on the safety and efficacy of newer-generation drug-eluting stents at long-term follow-up.

The trial was composed of 1,498 patients with STEMI requiring primary PCI who were randomly assigned in a 1:1 ratio to undergo EES (751 patients) or BMS (747 patients) implantation between 2008 and 2010. The primary endpoint was the patient-oriented combination of all-cause death, any recurrent myocardial infarction, and any revascularization.

The ESC noted that EXAMINATION was one of the first trials to use this combined endpoint, as recommended by the Academic Research Consortium. At 1- and 2-year follow-up, the patient-oriented endpoint was comparable between the stent groups. However, the need for repeat revascularization and, for the first time, the stent thrombosis rate were reduced by the second-generation drug-eluting stent.

The complete 5-year follow-up findings presented at the ESC Congress were obtained for more than 97% of patients. Baseline clinical and procedural characteristics were comparable between both groups. A total of 153 deaths, 62 recurrent myocardial infarctions, 209 revascularizations, and 35 definite/probable stent thrombosis episodes occurred during the 5-year follow-up.

The investigators reported that the primary endpoint was significantly reduced in the EES group compared to the BMS group (21.6% ± 1.5% vs 26% ± 1.6%; P = .03). Similarly, the device-oriented composite endpoint of cardiac death, target vessel myocardial infarction, and target lesion revascularization was significantly reduced by EES implantation (11.9% ± 1.2% vs 15.5% ± 1.3%; P = .04). The definite/probable stent thrombosis rate was nonsignificantly reduced in the EES group (2.1% ± 0.5% vs 3.1% ± 0.6%; P = .17).

In the ESC announcement, EXAMINATION Principal Investigator Manel Sabaté, MD, commented, “This is the first time since primary PCI demonstrated superiority over thrombolysis that a device (stent) has shown clinical benefit beyond restenosis prevention in a randomized, well-powered trial in STEMI.” 

Dr. Sabaté, who is a cardiologist at the Hospital Clinic de Barcelona in Spain, continued, “The 5-year follow-up of the EXAMINATION trial has demonstrated clinical superiority of the EES over a BMS in the patient-oriented primary endpoint, accomplishing the hypothesis of the trial. Our findings help to dispel worries that the early clinical benefits of drug-eluting stents in patients with STEMI may vanish over time because of late hazards including stent thrombosis and repeat revascularization due to neoatherosclerosis or restenosis.”

He concluded, “These results lay the foundation for future developments in stent technologies for primary PCI in patients with STEMI. Long-term outcomes of EES in this clinical scenario should be taken as reference for the evaluation of new bioresorbable polymer-based metallic stents or bioresorbable scaffolds.”