Impact of late stent malapposition after drug-eluting stent implantation on long-term clinical outcomes

Background and aims: The impact of late drug-eluting stent (DES) malapposition detected by optical coherence tomography (OCT) on long-term clinical outcomes has not been clearly established. We evaluated long-term clinical outcomes of late stent malapposition (LSM) detected by OCT in a qualified study population. Methods: A total of 428 patients were selected from previous randomized OCT studies that evaluated the degree of strut coverage of different DESs at a 3–12-month follow-up OCT examination. These patients were assigned to one of two groups based on the presence (n = 136) or absence (n = 292) of LSM on follow-up OCT images (performed at 7.0 ± 3.4 months after DES implantation). The cumulative rates of composite events (cardiac death, target-vessel-related myocardial infarction, target-vessel revascularization, and stent thrombosis) were compared between the two groups. Results: During 73.7 ± 18.3 months of follow-up, cardiac death or (very) late stent thrombosis did not occur in either group. The cumulative rate of composite events was similar among the patients in each group (6.2% in patients with LSM vs. 11.7% in those without LSM) [hazard ratio (HR) = 0.569, 95% confidence interval (CI) = 0.257–1.257, p = 0.163]. Target vessel-related myocardial infarction occurred in 0.7% of patients with LSM vs. 1.5% of those without LSM (HR = 0.521, 95% CI = 0.058–4.670, p = 0.560). Target-vessel revascularization was performed in 5.4% of patients with LSM vs. 10.2% of those without LSM (HR = 0.574, 95% CI = 0.246–1.343, p = 0.201). Conclusions: Cardiac death or (very) late stent thrombosis did not occur in patients with OCT-detected LSM during long-term follow-up. The presence of OCT-detected LSM was not associated with adverse clinical events.