Risk of late-acquired incomplete stent apposition after drug-eluting stent versus bare-metal stent. A meta-analysis from 12 randomized trials.

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.