The 12-month incidence of ScT reached 3% and could be significantly reduced when an optimized implantation strategy was employed. (retrospective multicentric registry and Mainz Intracoronary Database. The Coronary Slow-flow and Microvascular Diseases Registry [MICAT]; NCT02180178).

Background— Everolimus-eluting bioresorbable vascular scaffolds have been developed to improve late outcomes after coronary interventions. However, recent registries raised concerns regarding an increased incidence of scaffold thrombosis (ScT). The mechanism of ScT remains unknown. Methods and Results— The present study investigated angiographic and optical coherence tomography findings in patients experiencing ScT. Fifteen ScT (14 patients, 79% male, age 59±10 years) occurred at a median of 16 days (25%–75% interquartile range: 1–263 days) after implantation. Early ScT (<30 days) occurred in 8 cases (53%). Possible causal factors in these patients included insufficient platelet inhibition in 2 cases and procedural factors (scaffold underexpansion, undersizing, or geographical miss) in 4 cases. No obvious cause could be found in 2 early ScT. In late (>1 month) and very late (>1 year) ScT (respectively, 5 and 2 cases), 5 scaffolds showed intimal neovessels or marked peristrut low-intensity areas. Scaffold fractures were additionally found in 2 patients, and scaffold collapse was found in 1 patient with very late ScT. Extensive strut malapposition was the presumed cause for ScT in 1 case. One scaffold did not show any morphological abnormality. Thrombectomy specimens were analyzed in 3 patients and did not demonstrate increased numbers of inflammatory cells. Conclusions— The mechanisms of early ScT seem to be similar to metallic stents (mechanical and inadequate antiplatelet therapy). The predominant finding in late and very late ScT is peristrut low-intensity area.

The 3-year incidence of ScR was similar to that observed in similar settings with newer-generation drug-eluting stents. It is often associated with a benign presentation and a complex angiographic pattern. Predictors of ScR match those of metallic stent restenosis, and the implantation technique used at index appears to play an important role.

Optical coherence tomography-detected evaginations are relatively common after BVS implantation, but, as for modern drug-eluting metallic stents, major evaginations are very rare. Optical coherence tomography evidence of immature neointima and strut fractures were associated with more severe development of evaginations.

Different mechanisms underlie early and late ScT: although incomplete BRS deployment was a predictor of the former, the latter was associated with large vessel size and BRS undersizing. However, both phenomena are significantly less frequent with an optimized implantation technique. (Mainz Intracoronary Database. The Coronary Slow-flow and Microvascular Diseases Registry [MICAT]; NCT02180178).

Twelve months after BVS implantation, clinical, intracoronary imaging, and vasomotion data appear to provide a rationale for the use of BVS in the setting of ACS and the basis for a randomized study.

Background: Percutaneous intervention of calcified coronary lesions often requires lesion preparation with either balloon dilatation or atherectomy. We sought to evaluate the impact of lesion preparation strategy on stent expansion following preparation of severely calcified coronary lesions with modified (cutting/scoring) balloons (MB) versus rotational atherectomy (RA) and to evaluate the impact of calcium burden as assessed by optical coherence tomography (OCT) on acute stent performance. Methods: In the PREPARE-CALC trial (Comparison of Strategies to Prepare Severely Calcified Coronary Lesions), 200 patients with severely calcified coronary lesions were randomly assigned to receive either lesion preparation with MB or RA. In 122 patients, OCT was performed before lesion preparation and at the end of the procedure. The principal end point of this OCT sub-analysis was stent expansion as assessed by OCT. The key secondary end points included stent asymmetry and eccentricity. Results: The maximal calcific arc (257.5±96.7° versus 248.7±82.1°, P =0.59), thickness (1.34±0.29 versus 1.32±0.27 mm, P =0.76), and length of calcification (21.1±9.7 versus 24.0±10.9 mm, P =0.12) did not differ between the MB versus RA group. Lesion preparation with MB versus RA lead to comparable stent expansion (73.5±13.3% versus 73.1±12.2%, respectively, P =0.85). The use of RA did not have a significant impact on stent asymmetry or eccentricity compared with the use of MB. Length of calcified plaque appeared to be increased in patients with stent underexpansion, while thickness of calcified plaque was increased in patients with stent asymmetry. Target lesion revascularization at 9 months was 3.3% when MB was used and 1.6% when RA was performed ( P =0.62). Conclusions: In this OCT sub-analysis from the PREPARE-CALC trial, calcified plaque length was increased in patients with stent underexpansion, while its thickness was higher in patients with stent asymmetry, with no impact of the lesion preparation strategy. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02502851.

BackgroundDiabetes is among the strongest predictors of outcome after coronary artery stenting and the incidence of negative outcomes is still high in this specific group. Data of long-term outcomes comparing diabetic patients with non-diabetic patients treated with bioresorbable scaffolds are still incomplete. This work evaluates the long-term outcomes after implantation of a coronary bioresorbable scaffold (BRS) in diabetic patients compared to non-diabetics.MethodsPatients who received at least one Absorb BRS in the time of May 2012 to December 2014 were enrolled into this single-center registry. Quantitative coronary angiography (QCA) was performed.ResultsSix hundred fifty seven patients including 138 patients (21%, mean age 65 ± 11, 78% male) with diabetes were enrolled.Patients in the diabetic group were significantly older, were more likely to suffer from hypertension and hyperlipidemia and had more often a prior stroke or TIA as well as a reduced renal function (all P < 0.05). The initial stenosis was less severe in the diabetic group (74.8% vs. 79.6%, P = 0.036), but the residual stenosis after BRS implantation exceeded that of the control group (16.7% vs. 13.8%, P = 0.006).History of diabetes had no impact on the incidence of events within one year after BRS implantation. Beyond 1 year, diabetic patients had a higher incidence of cardiovascular death (6.9 vs. 1.4%, HR:5.37 [1.33–21.71], P = 0.001), scaffold restenosis (17.6 vs. 7.8%, HR:3.56 [1.40–9.05], P < 0.0001) and target lesion revascularization (P = 0.016). These results were confirmed in the propensity score analysis.In both diabetics and non-diabetics, there was a strong association (HR:18.6 [4.7–73.3]) between the risk of restenosis and the technique used at implantation; in contrast, the impact of vessel size was more manifest in non-diabetics than in diabetic patients, and an increased risk of restenosis was demonstrated for both large and small vessels.ConclusionAs for metal stents, beyond one year after implantation, diabetes was associated with an increased incidence of scaffold restenosis and related outcomes. This negative impact of diabetes was reset when an optimal implantation technique was used.Electronic supplementary materialThe online version of this article (10.1186/s12872-018-0811-7) contains supplementary material, which is available to authorized users.