Role of residual acute stent malapposition in percutaneous coronary interventions

OBJECTIVES: Assess clinical consequences of acute stent malapposition (ASM) in the context of the multicenter Centro per la Lotta Contro l'Infarto-Optimization of Percutaneous Coronary Intervention (CLI-OPCI) registry. BACKGROUND: ASM as important determinant of stent thrombosis (ST) risk remains controversial. METHODS: From 2009 to 2013, we retrospectively analyzed postprocedural optical coherence tomography (OCT) findings in 864 patients undergoing percutaneous coronary intervention, assessing prevalence and magnitude of ASM and exploring correlation with outcome, especially ST. RESULTS: Postprocedural OCT revealed a variable grade of ASM in 72.3% of stents without correlation between maximal strut-vessel distance and longitudinal extension (R = 0.164, P < 0.01). At a median follow up of 302 (IQ 127-567) days, ASM did not affect risk of following major cardiac adverse events (MACE); residual ASM was comparable in terms of thickness (median [quartiles] 0.21[IQ 0.1-0.4] vs. 0.20[IQ 0.0-0.3], P = 0.397) and length (2.0[IQ 0.5-4.1] vs. 2.2[IQ 0.0-5.2], P = 0.640) in patients with versus without MACE. The predictive accuracy for outcome was low (C-statistic 0.52, CI 95% 0.47-0.58, P = 0.394) as well for target lesion revascularization (HR 0.80, CI 95% 0.5-1.4) and ST (HR 0.71, CI 95% 0.3-1.5). Likewise, timing to MACE was not influenced by presence of such an ASM with similar rate of acute-subacute (HR 1.09, CI 95% 0.6-1.9), late (HR 0.91, CI 95% 0.5-1.8), and very late (HR 1.23, CI 95% 0.5-2.9) events. CONCLUSIONS: Limited ASM was a common finding after stent implantation, but was not associated to increased risk of stent failure or ST during mid-term follow-up.