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.