Long-term clinical outcomes of late stent malapposition detected by optical coherence tomography after drug-eluting stent implantation

Background-The relationship between late stent malapposition (LSM) and adverse cardiovascular events is controversial. Studies are needed to evaluate long-term (>5 years) clinical outcomes of LSM detected by optical coherence tomography (OCT) after drugeluting stent implantation. Methods and Results-We investigated long-term clinical outcomes of OCT-detected LSM in 351 patients who received drugeluting stents and were examined by both poststent and follow-up OCT (175±60 days after drug-eluting stent implantation) from January 2009 to December 2011. LSM was observed in 99 patients (28%). We evaluated the cumulative rate of composite events (cardiovascular death, target-vessel-related myocardial infarction, target-vessel revascularization, and stent thrombosis). During 80.1±24.5 months of follow-up, very late stent thrombosis did not occur in any patients with LSM. The cumulative 8-year rate of composite events was 7.3% in patients with LSM and 10.5% in patients without LSM (P=0.822, log-rank test). We further divided patients into the following 4 groups: patients with both late-persistent and late-acquired stent malapposition (n=23), patients with late-persistent stent malapposition alone (n=45), patients with late-acquired stent malapposition alone (n=31), and patients without LSM (n=252). The cumulative 8-year rates of composite events were similar among these 4 groups (0%, 9.6%, 9.7%, and 10.5%, respectively; P=0.468 by log-rank test). Conclusions-During long-term follow-up (>5 years), very late stent thrombosis did not occur in patients with OCT-detected LSM. The rates of adverse clinical events were similar between patients with LSM versus those without LSM. Presence of OCT-detected LSM was not associated with unfavorable clinical outcomes.