Cut-off value of strut-vessel distance for the resolution of acute incomplete stent apposition in the early phase using serial optical coherence tomography after cobalt-chromium everolimus-eluting stent implantation

Early vascular healing after neXt-generation drug-eluting stent implantation in Patients with non-ST elevation acute Coronary syndrome: a randomized optical coherence Tomography imaging study (EXPECT)

Early vascular healing after drug-eluting stent (DES) implantation is associated with better outcomes and lower incidence of in-stent thrombosis. To examine vascular healing response in patients with non-ST elevation acute coronary syndrome (NSTE-ACS) undergoing percutaneous coronary intervention (PCI) guided by optical coherence tomography (OCT) versus angiography alone. Sixty patients were randomized 1:1:1 to OCT-guided PCI with 3-month OCT follow-up (O3 group, n = 20), angiography-guided PCI with 3-month OCT follow-up (A3 group, n = 20), or angiography-guided PCI with 6-month OCT follow-up (A6 group, n = 20). The primary endpoint was the proportion of covered struts at 3- or 6-month follow-up. The proportion of covered struts in the O3 group was significantly higher than in the A3 group (95.2% vs. 92.3%, p < 0.001), but lower than in the A6 group (95.2% vs. 97.4%, p < 0.001). The O3 group had a lower proportion of incomplete strut apposition (ISA) than the A3 group (0.46% vs. 0.76%, p = 0.006), and higher than the A6 group (0.46% vs. 0.27%, p = 0.018) at follow-up. The optimal cut-off value of ISA after implantation of DES for predicting stent coverage at 3 and 6-month follow-up was 200 μm and 308 μm, respectively. Only one patient experienced target lesion revascularization in the A3 group during a 3-year clinical follow-up. In patients with NSTE-ACS undergoing PCI with DES, OCT guidance achieved higher strut coverage compared with angiography guidance at 3-month follow-up. However, the difference in the strut coverage between the OCT-guided group and the angiography-guided group at 6 months indicates that the degree of endothelialization may be more time-dependent instead of invasive device guidance.

Incidence and characteristics of incomplete stent apposition in calcified lesions: An optical coherence tomography study

BACKGROUND

Persistent or late acquired incomplete stent apposition (ISA) may be associated with late or very late stent thrombosis following drug-eluting stent implantation. Presence of calcium at the target lesion may increase the risk of ISA even after rotational atherectomy (RA) followed by stenting with high pressure balloon inflation. The aim of this study is to examine the incidence and characteristics of ISA in heavily calcified lesions.

METHODS

A total of 52 heavily calcified coronary artery lesions requiring RA plus stenting were selected and studied. After successful ablation followed by stent implantation, optical coherence tomography (OCT) was performed to assess stent expansion and apposition. Presence or absence of ISA was examined and maximal stent strut to vessel wall distance (max SV distance) was measured. In lesions with repeated OCT at follow-up, serial changes in ISA were investigated.

RESULTS

ISA was documented in 51 of 52 (98%) lesions. Mean max SV distance was 713 ± 371 μm. In lesions with serial OCT images (n = 11), max SV distance decreased significantly (692.1 ± 420.2 to 462.5 ± 387.0 μm, P < 0.01) but persisted in all but 2 lesions (82%).

CONCLUSIONS

ISA is frequently documented in heavily calcified lesions requiring RA. Significant ISA still persisted with minimal improvement in SV distance at follow-up. Prognostic impact of the persistent ISA in such calcified lesions needs further investigations.

Early Vascular Healing Following Bioresorbable-Polymer Sirolimus-Eluting Stent Placement Compared to That with Durable-Polymer Everolimus-Eluting Stent

A recent thinner strut drug-eluting stent might facilitate early strut coverage after its placement. We aimed to investigate early vascular healing responses after the placement of an ultrathin-strut bioresorbable-polymer sirolimus-eluting stent (BP-SES) compared to those with a durable-polymer everolimus-eluting stent (DP-EES) using optical coherence tomography (OCT) imaging.This study included 40 patients with chronic coronary syndrome (CCS) who underwent OCT-guided percutaneous coronary intervention (PCI). Twenty patients each received either BP-SES or DP-EES implantation. OCT was performed immediately after stent placement (baseline) and at 1-month follow-up.At one month, the percentage of uncovered struts reduced significantly in both the BP-SES (80.9 ± 10.3% to 2.9 ± 1.7%; P < 0.001) and DP-EES (81.9 ± 13.0% to 5.7 ± 1.8%; P < 0.001) groups, and the percentage was lower in the BP-SES group than in the DP-EES group (P < 0.001). In the BP-SES group, the percentage of malapposed struts also decreased significantly at 1 month (4.9 ± 3.7% to 2.6 ± 3.0%; P = 0.025), which was comparable to that of the DP-EES group (2.5 ± 2.2%; P = 0.860). The optimal cut-off value of the distance between the strut and vessel surface immediately after the placement to predict resolved malapposed struts was ≤ 160 μm for BP-SES and ≤ 190 μm for DP-EES.Compared to DP-EES, ultrathin-strut BP-SES demonstrated favorable vascular responses at one month, with a lower rate of uncovered struts and a comparable rate of malapposed struts.