Drug-Eluting or Bare-Metal Stents for Coronary Artery Disease

Posted by • September 26th, 2016

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Mr. Patrick is a 59-year-old man admitted to the hospital with a non-ST elevation myocardial infarction (NSTEMI). You start him on an aspirin, P2Y12 inhibitor, statin, and heparin, and discuss the need for cardiac catheterization and possible stent placement. Mr. Patrick has heard that there are different types of stents available and wants to know which one is best. How do you answer Mr. Patrick’s question?

Percutaneous coronary intervention (PCI) began with balloon angioplasty and has since evolved with the development of bare-metal stents, followed by first-generation drug-eluting stents, and now second-generation drug-eluting stents. Second-generation drug-eluting stents have been shown to be associated with lower risk of stent restenosis than first-generation drug-eluting stents. However, the newest drug-eluting stents and bare-metal stents have only been compared in small studies with limited generalizability and in meta-analyses. Additionally, since their development three decades ago, bare-metal stent technology has improved, with changes in metal composition and thinner struts. A large randomized trial that compares these updated bare-metal stents with contemporary drug-eluting stents in the era of medical therapy with antiplatelet agents and statins is needed.

In the Norwegian Coronary Stent Trial (NORSTENT), published in this week’s NEJM, investigators screened all patients at all eight PCI centers in Norway from 2008 to 2011, and enrolled those with lesions in native coronary arteries or coronary-artery grafts. After excluding patients with prior stent placement, limited life expectancy, and contraindications to long-term dual anti-platelet therapy, 9013 patients were randomized to receive either drug-eluting stents or bare-metal stents. Patients in both groups received aspirin (75 mg daily) indefinitely and clopidogrel (75 mg daily for 9 months) after PCI.

At 6 years of follow-up, the rate of the primary composite outcome of death from any cause and nonfatal spontaneous myocardial infarction did not differ between the drug-eluting stent group and the bare-metal stent group (16.6% vs. 17.1%, P=0.66). The rate of any revascularization, a secondary endpoint, was lower in the drug-eluting stent arm (16.5% vs. 19.8%, P<0.001). Rates of definite stent thrombosis were 0.8% and 1.2%, respectively (P=0.0498). Measures of quality of life and disease-specific health status on the Seattle Angina questionnaire did not differ between the groups.

In an accompanying editorial, Dr. Eric Bates from the Division of Cardiovascular Diseases at University of Michigan Medical Center writes, “The outcomes with second-generation drug-eluting stents make them preferred in most clinical situations, and recent recommendations for shorter-duration dual-antiplatelet therapy make that choice even more attractive.” But he adds, “Nevertheless, the use of bare-metal stents remains an important option for PCI in some patients,” citing previous studies showing low restenosis rates in patients with large-vessel diameters, and in those who cannot take dual anti-platelet therapy for an extended period of time due to bleeding, cost, anticipated surgery, or need for anticoagulation for another indication.

The NORSTENT study answers important questions about outcomes for patients with modern coronary artery stents. The results represent a large number of patients from across an entire country, allowing for greater generalizability than results of prior trials. John Jarcho, deputy editor at NEJM, noted that, “NORSTENT confirmed that the principal advantage of drug-eluting stents compared to bare-metal stents is the lower rate of subsequent revascularization. It also found that rates of stent thrombosis, a major concern with first-generation drug-eluting stents, are low with both newer-generation drug-eluting stents and bare-metal stents.”

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