Abstract and Introduction
Background Long-term safety and efficacy data of drug-eluting stents (DESs) in saphenous vein grafts (SVGs) are lacking. This study sought to compare the clinical outcomes of DES versus bare metal stents (BMS) in SVGs.
Methods We studied all stent implantations in SVGs in Sweden during 74 months between 2005 and 2011 registered in the Swedish Coronary Angiography and Angioplasty Registry. We evaluated outcome in patients who received DES compared with those who received BMS after adjustments for differences in clinical, vessel, and lesion characteristics.
Results Mean follow-up time was 3 years and 4 months. A total of 4,576 stents, implanted at 3,063 procedures, were included in the analysis of which 2,499 stents (54.6 %) were BMS and 2,077 (45.4%) were DES. The outcome analysis was based on 190 stent thromboses, 898 restenoses, and 523 deaths. The incidence of stent thrombosis did not differ between groups. When adjusted for baseline characteristics, including a propensity score for receiving DES, the incidence of restenosis was significantly lower with DES as compared with BMS (risk ratio 0.83, 95% CI 0.70–0.97, P = .019). There was a difference in mortality in the crude analysis between DES and BMS, and after multivariable adjustment, this difference remained statistically significant (risk ratio 0.80, CI 0.65–0.99, P = .038).
Conclusions The use of DES compared with BMS in SVGs was associated with a significantly lower adjusted incidence of restenosis and death in this large, national, all-encompassing propensity adjusted observational study.
Saphenous vein grafts (SVGs) remain the most frequently used graft material in coronary artery bypass grafting (CABG), but degeneration and lumen reduction in SVGs are common clinical problems. Repeat CABG is associated with a relatively high mortality and morbidity and percutaneous coronary intervention (PCI) is the preferred treatment with recurrence of symptomatic coronary disease.[2–4] Bare metal stents (BMS) have been shown to yield better clinical outcome than plain old balloon angioplasty in SVGs. However, in comparison with native vessels, the restenosis rate with BMS in SVGs is high.[5,6] In native coronary arteries, drug-eluting stents (DESs) have been associated with reduced rates of restenosis and need for target lesion revascularisation when compared with BMS.[7,8] This also includes complex lesions and lesions in patients with diabetes mellitus.[9,10]
In SVGs, DES implantation has only been investigated in a few, undersized prospective randomized trials, with conflicting results,[11–13] and in 1 recent trial of 610 patients showing reduction of the combined end point of death, myocardial infarction, and target lesion revascularization at 1 year. Moreover, also data from observational studies are to some extent conflicting. In a recent meta-analysis of >7,000 patients treated with BMS or DES for SVG disease, some of the quoted studies were in favor of DES, and others, neutral regarding target lesion revascularization, myocardial infarction, stent thrombosis, and death, whereas the overall conclusion of the weighted meta-analysis was in favor of DES.
Because of the shortage of large controlled clinical randomized trials and the patchy nature of observational data, more documentation of the role of DES in SVG disease is needed. Registry data cannot substitute randomized clinical trials but provide an important link between such trials and the real world. The Swedish Coronary Angiography and Angioplasty Registry (SCAAR) provides PCI data from an entire country with complete and continuous registration of all deaths and all repeat PCIs. Thus, in the current study, we were able to assess long-term rates of mortality, restenosis, and stent thrombosis in the largest complete cohort of consecutive patients treated with BMS and DES in SVGs published hitherto.
Am Heart J. 2012;164(1):87-93. © 2012 Mosby, Inc.
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