Aim: Stent thrombosis is a major safety issue after percutaneous coronary intervention (PCI) with stent implantation and it is associated with major early and mid-term complications. However, its long-term impact has been incompletely described. We thus aimed to appraise incidence, predictors and very long-term outlook of stent thrombosis after bare metal stent (BMS) or drug-eluting stent (DES) implantation.
Methods: We identified all patients undergoing PCI with BMS or DES at our center between July 2002 and June 2004. For the purpose of this study, we employed a composite definition of stent thrombosis including any Academic Research Consortium stent thromboses (definite, probable, or possible). We adjudicated the following clinical events: death, myocardial infarction (stent thrombosis related), repeated revascularization, and the composite of these events (i.e., major adverse cardiac events, MACE).
Results: A total of 1112 patients were included, 854 (76.8%) treated with BMS and 258 (23.2%) treated with DES. At a median follow-up of 61.2 (11.03) months the incidence of stent thrombosis was 20 (1.8%), with 14 (1.3%) definite, 4 (0.4%) probable, and 2 (0.1%) possible according to the American Research Consortium statement. Patients developing stent thrombosis were more likely to have more complex angiographic features at baseline (including angiographically evident thrombus, 4 [20%] vs. 73 [6.6%], P=0.02) and a saphenous vein graft as target vessel (2 [10%] vs. 28 [2.5%], P=0.04). Conversely, being treated with a BMS or a DES did not confer any significant decrease or increase in the risk of stent thrombosis, as 7 [35%] of those with stent thrombosis had received at least a DES vs. 251 [22.9%] of those without stent thrombosis, P=0.28). Early clinical outcomes (at 30 days) distinguishing those with stent thrombosis versus those without were as follows: death in four (20%) vs. 2 (0.2%, P<0.001), myocardial infarction in 1 (5%) vs. 7 (0.6%, P=0.02), revascularization in 5 (25%) vs. 43 (3.9%, P<0.001), and MACE in 8 (40%) vs. 53 (4.8%, P<0.001). After more than 60 months of clinical follow-up, outcomes were as follows: death in 7 (35%) vs. 147 (13.5%, P=0.057), myocardial infarction in 6 (30%) vs. 40 (3.6%, P<0.001), revascularization in 15 (75%) vs. 317 (29%, P<0.001), and MACE in 19 (95%) vs. 453 (41.5%, P<0.001).
Conclusion: This long-term registry shows that stent thrombosis remains a major safety issue after PCI with stent implantation, with a significant prognostic impact. However, in the present work the risk of stent thrombosis was similar with either DES or BMS, suggesting thus that DES are not associated with any increase in long-term thrombotic risk in comparison to BMS.