Severe acute stent malapposition after drug-eluting stent implantation: Effects on long-term clinical outcomes

Background-The effects of severe acute stent malapposition (ASM) after drug-eluting stent implantation on long-term clinical outcomes are not clearly understood. We evaluated long-term clinical outcomes of severe ASM using optical coherence tomography. Methods and Results-We pooled patient- and lesion-level data from 6 randomized studies. Five studies investigated follow-up drug-eluting stent strut coverage and one investigated ASM. In this data set, a total of 436 patients with 444 lesions underwent postintervention optical coherence tomography examination and these data were included in the analysis. Severe ASM was defined as lesions with ≥400 lm of maximum malapposed distance or ≥1 mm of maximum malapposed length. Composite events (cardiac death, target lesion-related myocardial infarction, target lesion revascularization, and stent thrombosis) were compared between patients with and without severe ASM. The postintervention optical coherence tomography findings indicated that 62 (14.2%) patients had lesions with ≥400 µm of maximum malapposed distance and 186 (42.7%) patients had lesions with ≥1 mm of maximum malapposed length. The 5-year clinical follow-up was completed in 371 (86.1%) of the eligible 431 patients. The cumulative rate of composite events was similar among the patients in each group during 5-year follow-up: 3.3% in patients with ASM ≥400 µm of maximum malapposed distance versus 3.1% in those with no ASM or ASM <400 µm of maximum malapposed distance (P=0.89), and 1.2% in patients with ASM ≥1 mm of maximum malapposed length versus 4.6% in those with no ASM or ASM <1 mm of maximum malapposed length (P=0.06). Conclusions-During the 5-year follow-up, ASM severity was not associated with long-term clinical outcomes in patients treated with drug-eluting stents.