Crochan O’Sullivan (Department of Cardiology, Bern University Hospital, Bern, Switzerland) and others report in EuroIntervention that while overlapping sirolimus-eluting stents are associated with poorer outcomes (such as an increased rate of target vessel revascularisation) compared with non-overlapping drug-eluting stents, everolimus-eluting stents are not.
O’Sullivan et al state that patients with overlapping earlier generation drug-eluting stents have a higher incidence of major adverse cardiac events (cardiac death, myocardial infarction, and ischaemia-driven target lesion revascularisation) than patients with non-overlapping or single drug-eluting stents. They add that newer generation drug-eluting stents are now widely used because they have improved on the safety and efficacy of earlier generation drug-eluting stents, but say: “The impact of newer generation drug-eluting stents on long-term clinical outcomes among patients with drug-eluting stent overlap is unknown.”
In the study, the authors used data from the prospective LESION (Long-term comparison of everolimus-eluting and sirolimus-eluting stents for coronary revascularisation) registry to compare the outcomes of patients with overlapping sirolimus-eluting stents or everolimus-eluting stents vs. those with non-overlapping drug-eluting stents. They identified 3,133 patients who had been treated with either sirolimus-eluting stents (1,532) or everolimus-eluting stents (1,601). Of these, 969 had stent overlap (389 with sirolimus-eluting stents and 580 with everolimus-eluting stents).
Overall, patients with overlapping drug-eluting stents were significantly more likely to experience the study’s primary endpoint of death, myocardial infarction, or target lesion revascularisation (p<0.001) than those with non-overlapping drug-eluting stents. Categorised by stent type, patients with overlapping sirolimus-eluting stents were significantly more likely to experience this endpoint (p<0.001) but patients with overlapping everolimus-eluting stents were not.
According to O’Sullivan et al, their findings are clinically relevant for several reasons: drug-eluting stent overlap is relatively common, the data for overlapping sirolimus-eluting stents corroborates previous findings (from a separate cohort of patients), and the impairment associated with overlapping drug-eluting stents seems to be no longer apparent with the newer generation everolimus-eluting stent. They note: “The mechanism underlying the improved long-term clinical outcomes with everolimus-eluting stent overlap are unclear but may be related to the lower strut thickness resulting in less arterial injury and more rapid and complete endothelialisation, a biocompatible polymer less prone to hypersensitivity reactions, and a lower dose of antiproliferative drug thereby causing less vascular toxicity at the site of the overlap.”
They conclude: “Drug-eluting stent overlap is associated with impaired clinical outcomes during long-term form follow-up. Compared with early generation sirolimus-eluting stents, newer generation everolimus-eluting appear to overcome this limitation and provide similar clinical outcomes irrespective of drug-eluting stent overlap status.”
Study author Stephan Windecker, Department of Cardiology, Bern University Hospital, Bern, Switzerland, says he believes that most new generation drug-eluting stents will have overcome the limitation of stent overlap.