Stent Optimization Using Optical Coherence Tomography and Its Prognostic Implications After Percutaneous Coronary Intervention.

Background Stent underexpansion has been known to be associated with worse outcomes. We sought to define optical coherence tomography assessed optimal stent expansion index (SEI), which associates with lower incidence of follow-up major adverse cardiac events (MACEs). Methods and Results A total of 315 patients (involving 370 lesions) who underwent optical coherence tomography-aided coronary stenting were retrospectively included. SEI was calculated separately for equal halves of each stented segment using minimum stent area/mean reference lumen area ([proximal reference area+distal reference area]/2). The smaller of the 2 was considered to be the SEI of that case. Follow-up MACE was defined as a composite of all-cause death, myocardial infarction, stent thrombosis, and target lesion revascularization. Average minimum stent area was 6.02 (interquartile range, 4.65-7.92) mm2, while SEI was 0.79 (interquartile range, 0.71-0.86). Forty-seven (12.7%) incidences of MACE were recorded for 370 included lesions during a median follow-up duration of 557 (interquartile range, 323-1103) days. Receiver operating characteristic curve analysis identified 0.85 as the best SEI cutoff (<0.85) to predict follow-up MACE (area under the curve, 0.60; sensitivity, 0.85; specificity, 0.34). MACE was observed in 40 of 260 (15.4%) lesions with SEI <0.85 and in 7 of 110 (6.4%) lesions with SEI ≥0.85 (P=0.02). Least absolute shrinkage and selection operator regression identified SEI <0.85 (odds ratio, 3.55; 95% CI, 1.40-9.05; P<0.01) and coronary calcification (odds ratio, 2.47; 95% CI, 1.00-6.10; P=0.05) as independent predictors of follow-up MACE. Conclusions The present study identified SEI <0.85, associated with increased incidence of MACE, as the optimal cutoff in daily practice. Along with suboptimal SEI (<0.85), coronary calcification was also found to be a significant predictor of follow-up MACE.

Optical coherence tomography tissue coverage and characterization at six months after implantation of bioresorbable scaffolds versus conventional everolimus eluting stents in the ISAR-Absorb MI trial.

PURPOSE: Data regarding vessel healing by optical coherence tomography (OCT) after everolimus-eluting bioresorbable scaffolds (BRS) or everolimus-eluting metallic stent (EES) implantation in acute myocardial infarction (AMI) patients is scarce. We compared OCT findings after BRS or EES implantation in patients with AMI enrolled in a randomized trial. METHODS: In ISAR-Absorb MI, AMI patients were randomized to BRS or EES implantation, with 6-8 month angiographic follow-up. This analysis includes patients who underwent OCT during surveillance angiography. Tissue characterization was done using grey-scale signal intensity analysis. The association between OCT findings and target lesion failure (TLF) at 2 years was investigated. RESULTS: OCT was analyzed in 103 patients (2237 frames, 19,827 struts) at a median of 216 days post-implantation. Of these, 70 were treated with BRS versus 32 with EES. Pre-(92.8 vs. 68.7%, p = 0.002) and post-dilation (51.4 vs. 12.5%, p < 0.001) were more common in BRS as compared to EES. Strut coverage was higher in BRS vs. EES (97.5% vs. 90.9%, p < 0.001). Mean neointimal thickness was comparable in both groups [85.5 (61.9, 124.1) vs. 69.5 (32.7, 127.5) µm, respectively, p = 0.20]. Mature neointimal regions were numerically more common in BRS (43.0% vs. 24.6%; p = 0.35); this difference was statistically significant in ST-elevation myocardial infarction patients (40.9% vs. 21.1%, p = 0.03). At two-years, 8 (7.8%) patients experienced TLF. Mean neointimal area [0.61 (0.21, 1.33) vs. 0.41 (0.11, 0.75) mm2, p = 0.03] and mean neointimal coverage [106.1 (65.2, 214.8) vs. 80.5 (53.5, 122.1) µm, p < 0.01] were higher, with comparable tissue maturity, in lesions with versus without TLF. CONCLUSIONS: In selected patients who underwent OCT surveillance 6-8 months after coronary intervention for AMI with differing implantation characteristics depending on the device type used, vessel healing was more advanced in BRS compared with EES, particularly in the STEMI subgroup.