Risk of Late-Acquired Incomplete Stent Apposition: DES vs BMS
Background: Incomplete stent apposition (ISA) is an unusual finding of intravascular ultrasound (IVUS) that may occur both after drug-eluting stent (DES) or bare-metal stent (BMS) implantation and could be associated with late stent thrombosis. Controversy still remains about whether the risk of late-acquired ISA is increased after DES implantation. This meta-analysis aimed to clarify whether DES implantation is associated with an increased risk of late-acquired ISA.
Methods: We performed a meta-analysis from 12 randomized trials that compared DES and BMS and included IVUS follow up: TAXUS II (n = 469), TAXUS IV (n = 187), TAXUS V (n = 213) and VI (n = 147), ASPECT (n = 81), DELIVER (n = 65), SIRIUS (n = 141), DIABETES (n = 140), ENDEAVOR II (n = 250), FUTURE I and II (n = 83), and SPIRIT-I (n = 58). In these trials, 1,834 patients (972 DES, and 862 BMS) underwent immediate and follow-up IVUS examination.
Results: There was no heterogeneity among the trials (Q-test for heterogeneity: Chi2: 7.69; (p = 0.26), I2: 22%. Out of the 1,834 patients undergoing serial IVUS examination, 85 developed late-acquired ISA (4.6%). This incidence was significantly higher in DES compared with BMS (6.5% vs. 2.6%, respectively; odds ratio [OR] 2.48, 95% confidence interval [CI] 1.26 to 4.87; p = 0.008). That means that the risk of developing late-acquired ISA is 2.5 times higher after DES versus BMS implantation. No stent thrombosis occurred in the patients diagnosed with ISA over a period up to 12 months.
Conclusion: DES implantation could be associated with an increased risk of late ISA in comparison with BMS. The clinical implication of late ISA in the long term remains to be clarified.
Drug-eluting stents (DES) have demonstrated the capacity to reduce binary angiographic restenosis, and the need for subsequent revascularization procedures of the target vessel. Serial intravascular ultrasound (IVUS) studies have demonstrated that DES dramatically reduce the degree of neointimal hyperplasia compared to bare metal stent (BMS). DES do not increase the risk of stent thrombosis in comparison with BMS during the first year after stent implantation, at least under prolonged double antiplatelet therapy. Conversely, long-term follow up of randomized trials have shown that DES seem to increase the risk of stent thrombosis more than 1 year after implantation (very late stent thrombosis), but the reasons have not been elucidated yet.
IVUS is of help in the evaluation of changes of vessel wall that occur after percutaneous coronary interventions. Late-acquired incomplete stent apposition (ISA) is a relatively unusual IVUS finding that may occur both after DES and BMS implantation, and could be associated with late stent thrombosis. Intravascular brachytherapy has an antirestenotic effect by inhibiting the proliferation of vascular smooth muscle cells similar to DES, and its use was associated with a high incidence of late thrombosis. Late-acquired ISA was proposed as a mechanism for late thrombosis after brachytherapy. Controversy still remains about whether the risk of late-acquired ISA is increased after DES implantation. In patients from two nonrandomized studies in "the real-world" practice, the reported incidence of late-acquired ISA was similar after DES and BMS, approximately 5%. The purpose of the present study was to ascertain whether DES are associated with an increased risk of late-acquired ISA. For this purpose, we have performed a meta-analysis from twelve randomized, controlled trials that compared DES and BMS, and included one IVUS evaluation.
Background: Incomplete stent apposition (ISA) is an unusual finding of intravascular ultrasound (IVUS) that may occur both after drug-eluting stent (DES) or bare-metal stent (BMS) implantation and could be associated with late stent thrombosis. Controversy still remains about whether the risk of late-acquired ISA is increased after DES implantation. This meta-analysis aimed to clarify whether DES implantation is associated with an increased risk of late-acquired ISA.
Methods: We performed a meta-analysis from 12 randomized trials that compared DES and BMS and included IVUS follow up: TAXUS II (n = 469), TAXUS IV (n = 187), TAXUS V (n = 213) and VI (n = 147), ASPECT (n = 81), DELIVER (n = 65), SIRIUS (n = 141), DIABETES (n = 140), ENDEAVOR II (n = 250), FUTURE I and II (n = 83), and SPIRIT-I (n = 58). In these trials, 1,834 patients (972 DES, and 862 BMS) underwent immediate and follow-up IVUS examination.
Results: There was no heterogeneity among the trials (Q-test for heterogeneity: Chi2: 7.69; (p = 0.26), I2: 22%. Out of the 1,834 patients undergoing serial IVUS examination, 85 developed late-acquired ISA (4.6%). This incidence was significantly higher in DES compared with BMS (6.5% vs. 2.6%, respectively; odds ratio [OR] 2.48, 95% confidence interval [CI] 1.26 to 4.87; p = 0.008). That means that the risk of developing late-acquired ISA is 2.5 times higher after DES versus BMS implantation. No stent thrombosis occurred in the patients diagnosed with ISA over a period up to 12 months.
Conclusion: DES implantation could be associated with an increased risk of late ISA in comparison with BMS. The clinical implication of late ISA in the long term remains to be clarified.
Drug-eluting stents (DES) have demonstrated the capacity to reduce binary angiographic restenosis, and the need for subsequent revascularization procedures of the target vessel. Serial intravascular ultrasound (IVUS) studies have demonstrated that DES dramatically reduce the degree of neointimal hyperplasia compared to bare metal stent (BMS). DES do not increase the risk of stent thrombosis in comparison with BMS during the first year after stent implantation, at least under prolonged double antiplatelet therapy. Conversely, long-term follow up of randomized trials have shown that DES seem to increase the risk of stent thrombosis more than 1 year after implantation (very late stent thrombosis), but the reasons have not been elucidated yet.
IVUS is of help in the evaluation of changes of vessel wall that occur after percutaneous coronary interventions. Late-acquired incomplete stent apposition (ISA) is a relatively unusual IVUS finding that may occur both after DES and BMS implantation, and could be associated with late stent thrombosis. Intravascular brachytherapy has an antirestenotic effect by inhibiting the proliferation of vascular smooth muscle cells similar to DES, and its use was associated with a high incidence of late thrombosis. Late-acquired ISA was proposed as a mechanism for late thrombosis after brachytherapy. Controversy still remains about whether the risk of late-acquired ISA is increased after DES implantation. In patients from two nonrandomized studies in "the real-world" practice, the reported incidence of late-acquired ISA was similar after DES and BMS, approximately 5%. The purpose of the present study was to ascertain whether DES are associated with an increased risk of late-acquired ISA. For this purpose, we have performed a meta-analysis from twelve randomized, controlled trials that compared DES and BMS, and included one IVUS evaluation.
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