Difference of vascular healing between bioabsorbable-polymer and durable-polymer new generation drug-eluting stents: an optical coherence tomographic analysis

Direct Comparison of Rotational vs Orbital Atherectomy for Calcified Lesions Guided by Optical Coherence Tomography

BACKGROUND

There are several retrospective studies comparing rotational atherectomy (RA) and orbital atherectomy (OA), but all percutaneous coronary interventions (PCIs) in those studies were not performed under intracoronary imaging guidance.

OBJECTIVES

This study sought to compare the efficacy and safety of optical coherence tomography (OCT)-guided PCI with RA vs OA.

METHODS

The DIRO (To directly compare RA and OA for calcified lesions, a prospective randomized trial) trial was conducted. We enrolled patients with de novo calcified lesions (arc >180°) assessed by OCT or angiographically moderate or severe calcifications if the OCT catheter could not cross the lesion before any intervention. Eligible patients were randomly 1:1 allocated to lesion preparation with RA vs OA. Stent expansion was defined as the minimum stent area divided by the distal reference area multiplied by 100. Tissue modification was assessed using preatherectomy and postatherectomy OCT images. Procedural outcomes including periprocedural myocardial infarctions were evaluated. Furthermore, clinical events and vascular healing evaluated by OCT at 8 months postprocedure were assessed.

RESULTS

The stent expansion was significantly greater in the RA group vs the OA group (99.5% vs 90.6%; P = 0.02). The maximum atherectomy area was significantly larger in the RA group than in the OA group (1.34 [IQR: 1.02-1.89] mm2 vs 0.83 [IQR: 0.59-1.11] mm2; P = 0.004). The procedural outcomes and clinical events at 8 months did not differ between the groups. The vascular healing was sufficient in both groups.

CONCLUSIONS

The prospective randomized DIRO trial revealed that RA could produce a more favorable tissue modification, which may lead to a larger stent expansion than OA in heavily calcified lesions.

Early vascular healing of ultra-thin strut polymer-free sirolimus-eluting stents in acute coronary syndrome: USUI-ACS study

Ultra-thin strut polymer-free sirolimus-eluting stent (UPF-SES) have two novel characteristics, ultra-thin strut and polymer-free coating, which have the potential to achieve early re-endotherialization. However, a little is known whether early vascular healing of UPF-SES can be achieved in patients with acute coronary syndrome (ACS). The aim of this study was to evaluate the vascular healing after an implantation of UPF-SES in patients with ACS using optical coherence tomography (OCT) at 3 months after the stent implantation. From September 2020 and January 2021, a total of 31 consecutive patients presenting with ACS who underwent OCT-guided percutaneous coronary intervention (PCI) and 3 month follow-up OCT examination were enrolled in the USUI-ACS study. The endpoints of this study were neointimal strut coverage, malapposition, and mean neointimal hyperplasia (NIH) thickness at 3 month follow-up. Over a mean follow-up of 91 days after the initial PCI, the follow-up OCT was examined. The median percentage of covered struts was 98.4% and malapposed struts 0%, and the mean NIH thickness was 80 μm. UPF-SES exhibited an excellent early vascular healing at 3 months in patients with ACS.

Preferable vascular healing of ultrathin strut biodegradable-polymer sirolimus-eluting stents in patients with acute coronary syndrome

This study aimed to compare the strut coverage between Orsiro ultrathin struts biodegradable polymer sirolimus-eluting stents (O-SES) and Xience thin struts durable polymer everolimus-eluting stents (X-EES) in acute coronary syndrome (ACS) patients using optical coherence tomography (OCT). In BIOSTEMI trial, O-SESs were superior to X-EESs with respect to target lesion failure in ACS patients. However, there were few reports comparing intravascular imaging between the two stents in ACS. Between August 2016 and February 2020, 49 lesions from 49 ACS patients who underwent OCT-guided percutaneous coronary intervention were enrolled. We compared vascular healing using OCT between O-SESs and X-EESs at 8 months after stenting. The protocol was approved by the Osaka Rosai Hospital ethics committee. Among 49 lesions, the X-EES group consisted of 24 lesions and the O-SES of 25 lesions. The percentage of covered strut, the percentage of malapposed strut and mean neointimal thickness at 8 months were evaluated. In the 8-month OCT analysis, the proportion of covered strut was significantly higher in the O-SES group than in in the X-EES group (97.3% vs. 92.5%; p = 0.010). On the other hand, there were no significant differences in the frequency of malapposed strut (0.4% vs 0.3%, p = 0.609). The O-SES group had the significantly thinner neointima compared to the X-EES group (60 μm vs 84 μm, p = 0.001). Compared to X-EESs, O-SESs showed better strut coverage and thinner neointima in ACS patients at 8 months follow-up. Ultra-thin strut and silicon carbide passive coating may play a key role in better vascular healing.