Ten-Year Clinical Outcomes of Late-Acquired Stent Malapposition After Coronary Stent Implantation

Objective: The goal of this study was to determine the impact of late-acquired stent malapposition (LASM) on long-term clinical outcomes in patients treated with coronary stent implantation. Approach and Results: We investigated major adverse cardiac event during 10 years after 6-month intravascular ultrasound examination using our previous studies database. A total of 732 patients treated with bare-metal stent (54 LASM versus 678 non-LASM) and 529 patients treated with first-generation drug-eluting stent (82 LASM versus 447 non-LASM), who did not have clinical event or censoring at the time of follow-up intravascular ultrasound, were included for the present analysis. major adverse cardiac event was defined as the composite of cardiac death, target vessel-related myocardial infarction, target lesion revascularization and stent thrombosis. Multivariable adjustment and inverse probability weight were performed to consider baseline differences. After multivariable adjustment, LASM was related to a greater risk of major adverse cardiac event (hazard ratio, 1.666 [95% CI, 1.041-2.665]; P=0.0333) and very-late stent thrombosis (hazard ratio, 3.529 [95% CI, 1.153-10.798]; P=0.0271) than non-LASM in patients treated with first-generation drug-eluting stent, but not in those treated with bare-metal stent. Results were consistent after inverse probability weight. Among patients with LASM of first-generation drug-eluting stent, no late stent thrombosis occurred in patients who continued to receive dual antiplatelet therapy. Conclusions: The relationship between LASM and major adverse cardiac event might depend on the type of implanted stents during the long-term follow-up, highlighting the clinical significance of polymers and drugs in drug-eluting stent system.