Bioresorbable vascular scaffolds for complex chronic total occlusions

Bioresorbable Scaffold Use in Coronary Chronic Total Occlusions: A Long-Term, Single-Center Follow-Up Study

Background and Objectives: Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) is often associated with longer total stent length. Our aim was to evaluate the long-term safety and effectiveness of bioresorbable scaffold (BRS) implantation in CTO to avoid using a full metal jacket. Materials and Methods: We conducted a single-center prospective longitudinal case study including 34 patients who underwent PCI of CTO with at least one BRS and drug-eluting stent (DES) implantation (n = 27) or BRS-only at the Latvian Centre of Cardiology between 2016 and 2018. Quantitative coronary angiography (QCA) and intravascular ultrasound were performed during the index procedure and long-term follow-up. Results: Of 34 patients with a mean age of 60.6 ± 9.5 years, 76.5% were male. The most common CTO artery was the right coronary artery (73.5%, n = 25). The median length of occlusion was 23.0 mm (interquartile range (IQR) = 13.9-32.7), with a total mean BRS/DES length of 49.6 ± 20.4 mm. During the median follow-up of 5.6 years (IQR = 5.0-5.9), the primary endpoint of target vessel re-occlusion occurred in 5.9% (n = 2) of patients. Target lesion revascularization (TLR) was performed in 35.3% (n = 12) of patients, with a mean time to TLR of 62.5 (95% confidence interval (CI), 53.9-71.2) months. Through QCA, there was a statistically significant increase in median residual diameter stenosis (20.1-31.4%, p < 0.01) and residual length of stenosis (5.2-7.1%, p = 0.04) compared with the index procedure. Conclusions: Our study demonstrates that BRS is a safe and feasible option for PCI of CTO, allowing for the avoidance of long segment stenting and ensuring long-term patency of the coronary artery.

Impact of Selection Preference on Longer-Term Outcomes between Bioresorbable Vascular Scaffold versus Everolimus-Eluting Stent for True Lumen Tracking-Recanalized Chronic Total Occlusion

Creation of sizable subintima during intervention for chronic total occlusions (CTO) could lead to the key selection preference of metallic stents rather than bioresorbable vascular scaffolds (BVS) and then possibly deviate the outcome comparisons in real-world studies. By including recanalized CTO with true lumen tracking, we tested if any selection preference remained and compared the outcomes between everolimus-eluting stent (EES) and BVS implantation.Among 211 consecutive CTO interventions with true lumen tracking from August 2014 to April 2018 when BVS was available, we compared the clinical and interventional features between 28 patients with BVS and 77 patients with EES implantation. With propensity score matching and a median follow-up of 50.5 (37.3-60.3) months, we further assessed 25 patients with BVS and 25 with EES for target vessel failure (TVF: cardiac death, target vessel myocardial infarction, and target lesion revascularization).Multivariate analyses showed that BVS was still favored in the presence of LAD CTO (odds ratio (OR) = 3.4, 95% confidence interval (CI) = 1.0-11.7) and an average scaffold/stent size ≥ 3 mm (OR = 10.5, 95% CI = 3.0-37.3). EES was preferred for lesions with a J-CTO score ≥ 3 (OR = 19.3, 95% CI = 3.4-110.8) and multivessel intervention necessary at index procedure (OR = 11.3, 95% CI = 1.9-67.3). With matched comparisons, the TVF-free survival of EES was better than that of BVS for CTO recanalization (P = 0.049 by log-rank test) at long-term follow-up.Even with true lumen tracking techniques, selection bias remained substantial when determining either device for CTO implantation. The matched comparison of outcomes suggested the unfavorable longer-term impacts of the first generation of BVS on CTO lesions.

Lesion impacts on long-term outcomes in patients implanted with bioresorbable vascular scaffold

BACKGROUND

Bioresorbable vascular scaffold (BVS) had been implanted to several kinds of complex coronary lesions in real-world practice. We tested if long-term outcomes of BVS for complex lesions would be worse than that for relatively simple lesions.

METHODS

We analyzed 457 patients (59 ± 12 years, 87% male) with 714 BVS implanted for their 529 lesions and median follow-up of 32.7 (26.8-39.3) months. Complex group (N = 284) was defined as those with BVS for acute coronary syndrome, chronic total occlusion, bifurcation/ostial lesions, instent restenosis/hybrid with metallic stents, diffuse lesions (overlapped by 2 BVS with each ≧ 18 mm), venous graft/left main lesions, or lesions after rotablation. We compared their outcomes with the remaining 173 patients as non-complex group.

RESULTS

The complex group had more chronic kidney disease (7% vs. 2%), multivessel disease (78% vs. 65%), use of intravascular imaging (40% vs. 23%), and more BVS (1.8 ± 0.9 vs. 1.1 ± 0.3) with longer total lengths (47 ± 22 vs. 29 ± 8 mm) implanted than non-complex group (all p < 0.05). However, the long-term target lesion revascularization (TLR) or target lesion failure (TLF) was similar (log rank p > 0.05) between the two groups. Multivariate Cox regression analyses showed BVS for ACC/AHA type C lesions was independently associated with higher risks of TLR (hazard ratio: 2.7, 95% CI = 1.1-6.6) and TLF (hazard ratio: 2.6, 95% CI = 1.1-6.3).

CONCLUSIONS

Comparable outcomes were found between BVS for complex and non-complex lesion category. However, higher risks of TLR and TLF for type C lesions still suggested the prognostic impact of lesion complexity on long-term outcomes of BVS.

Use of Coronary Computed Tomographic Angiography to Facilitate Percutaneous Coronary Intervention of Chronic Total Occlusions

Chronic total coronary occlusions (CTO) are found frequently in coronary artery disease; however, the technical challenge to open the occlusion by percutaneous coronary intervention is considerably higher than for nonocclusive lesions. The angiographic analysis is limited by the inability to visualize the occluded segment and requires a dual injection approach from donor and recipient vessel to assess the CTO. Therefore, imaging of the CTO by computed tomographic angiography can provide additional information on the vessel course within the CTO segment, specifically the degree and extent of calcification, and maybe even be superior to angiography to analyze the proximal cap morphology. This had been integrated in a score to predict the interventional success. This information provides a valuable means to better plan the procedure and the required strategy. In addition, an integration of the computed tomographic angiography is possible by synchronization with the gantry position and movement of the angiography system during percutaneous coronary intervention, illustrating the course of the occluded segment and possible obstacles in the way. It remains to be established which patient will most likely profit from this additional preprocedural examination involving increased radiation and contrast media exposure and institutional expenses.