Everolimus-Eluting Stent Versus Bare-Metal Stent in ST-Segment Elevation Myocardial Infarction (EXAMINATION): 1 Year Results of a Randomised Controlled Trial

Study Questions:

What is safety and efficacy of an everolimus-eluting stent (EES) in patients undergoing percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI)?

Methods:

The EXAMINATION trial authors enrolled 1,504 patients with STEMI undergoing PCI within 48 hours of symptom onset at 12 medical centers in three countries and randomly assigned (ratio 1:1) them to receive EES or bare-metal stents (BMS). Patients were blinded to treatment. The primary endpoint was the combined endpoint of all-cause death, any recurrent MI, and any revascularization at 1 year, and was analyzed by intention to treat. The secondary endpoints of the study included the combined endpoint of cardiac death, target vessel MI, or target lesion revascularization, and rates of all-cause or cardiac death, recurrent MI, target lesion or target vessel revascularization, stent thrombosis, device and procedure success, and major and minor bleeding.

Results:

The trial enrolled 1,504 patients, of whom 1,498 patients were randomly assigned to receive EES (n = 751) or BMS (n = 747). There was no difference in the primary endpoint between the two stents (11.9% in the EES group vs. 14.2% in the BMS group, p = 0.19). EES was associated with a lower risk of target lesion revascularization (2.1% vs. 5%, p = 0.003) and target vessel revascularization (3.7% vs. 6.8%, p = 0.0077). There was no difference in the rates of all-cause mortality (3.5% vs. 3.5%) or cardiac death (3.2% vs. 2.8%). Definite stent thrombosis rates were significantly lower in the EES group (0.5% vs. 1.9%, p = 0.019). Bleeding rates at 1 year were similar between groups (3.9% vs. 5.2%, p = 0.19).

Conclusions:

Use of EES was not associated with a reduction in the primary endpoint of death, MI, or revascularization, although a reduction in stent thrombosis, target vessel revascularization, and target lesion revascularization was seen.

Perspective:

This study demonstrates the excellent outcome with either BMS or EES in patients undergoing PCI for STEMI. The BMS arm patients had an excellent outcome, suggesting that DES use may not be routinely warranted in this population. The outcomes with BMS in this trial were considerably superior than have been reported with other BMS, and it is not clear if these findings are unique to the stent platform that was used (Vision Multi-link), or reflect characteristics unique to the study population. Secondly, the lower rate of stent thrombosis with EES corroborates the results of a recent meta-analysis, and suggests that the EES platform may indeed carry a lower rate of stent thrombosis compared with BMS, a finding that has not been demonstrated for any other drug-eluting stent (Palmerini, et al., Lancet 2012;379:1393-1402).

Clinical Topics: Invasive Cardiovascular Angiography and Intervention

Keywords: Myocardial Infarction, Thrombosis, Drug-Eluting Stents, Sirolimus, Angioplasty, Balloon, Coronary, Stents, Percutaneous Coronary Intervention


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