Drug-eluting stents: Weighing the pros and cons of this therapy and its alternatives

Cardiology Review® Online, August 2008, Volume 25, Issue 8

SORT OUT II trial results support our current understanding of drug-eluting stent use: (1) there is no difference in efficacy or safety among different drug-eluting stents; (2) stent thrombosis rates are highest in the first month after stent implantation; and (3) late stent thrombosis rates are low and not influenced by discontinuation of clopidogrel therapy at 12 months.

Drug-eluting stents have dramatically decreased the need for coronary artery bypass graft (CABG) surgery and repeat percutaneous coronary intervention (PCI); however, late stent thrombosis is a risk, and while small, it should be considered because of its association with sudden death or acute myocardial infarction (MI). Clinicians need to decide whether the decreased risk of death and MI from avoiding CABG surgery, restenosis, or repeat PCI outweighs the risk of death or MI from late stent thrombosis with routine and off-label stent use.

SORT OUT II (Danish Organization on Randomized Trials with Clinical Outcome) trial results support our current understanding of drug-eluting stent use: (1) there is no difference in efficacy or safety among different drug-eluting stents; (2) stent thrombosis rates are highest in the first month after stent implantation; and (3) late stent thrombosis rates are low and not influenced by discontinuation of clopidogrel (Plavix) therapy at 12 months. The major limitation of the study is failure to include a bare-metal stent reference arm. Moreover, few data exist comparing drug-eluting stents with optimal medical therapy or CABG surgery.

Current recommendations state that dual antiplatelet therapy with aspirin and clopidogrel should continue after drug-eluting stent implantation for up to 1 year if bleeding risk is low. Consequently, these stents should be avoided if there are financial barriers to continuing prolonged dual antiplatelet therapy, social barriers that limit patient compliance, medical issues involving bleeding risks, or the need for procedures that would interrupt antiplatelet therapy.

The case report highlights the risk of stent thrombosis in the perioperative period, although the main risk of stent thrombosis is withdrawal of dual antiplatelet therapy early after stent implantation, with little risk after 1 year if aspirin is continued. It seems logical to associate discontinuation of antiplatelet therapy with the thrombotic event, but stent thrombosis can also occur in patients on dual antiplatelet therapy. Indefinite use of dual antiplatelet therapy is not guaranteed protection from repeat stent thrombosis. In the reported case, the risk after the second procedure is higher because of the initial episode of stent thrombosis and the subsequent placement of 2 additional long, overlapping drug-eluting stents.

No intervention is risk-free. Death can result from bleeding complications, MI, surgery complications, stent thrombosis, or graft occlusion. Recent data suggest that drug-eluting stents have lower mortality and target vessel revascularization rates than bare-metal stents, but a slightly increased risk of late thrombosis and MI. The benefits and risks of all coronary revascularization options must be weighed when deciding which intervention to pursue.