Chronic Total Occlusion is Not a Risk Factor for Mortality in Patients With Successful Percutaneous Coronary Intervention: A Cohort Study.

Background Fifteen percent of patients with coronary artery disease undergoing angiography have a chronic total occlusion (CTO). The current study aimed to investigate the long-term prognosis after successful and unsuccessful CTO percutaneous coronary intervention (PCI) compared with PCI for non-CTO lesions. Methods and Results The current study was designed as an observational, region-wide, register-based cohort study enrolling all patients undergoing PCI in the Central Region of Denmark in 2009 to 2019. Patients were stratified into non-CTO, successful CTO, and unsuccessful CTO revascularization. Patients were followed until an event or January 1, 2022. The primary end point was all-cause mortality. In 21 141 patients enrolled, 2108 underwent CTO PCI. Clinical presentation was acute coronary syndrome in 11 879 patients and chronic coronary syndrome in 7887 patients. After a median of 5.7 years (interquartile range, 3.3-8.8), long-term all-cause mortality was higher after CTO PCI compared with non-CTO PCI, but the difference was statistically insignificant when adjusting for clinical factors (unadjusted hazard ratio [HR], 1.19 [95% CI, 1.09-1.29], adjusted HR, 1.08 [95% CI, 0.97-1.20]; P=0.165). After successful CTO PCI, no difference compared with non-CTO PCI was observed (unadjusted HR, 0.99 [95% CI, 0.90-1.10], adjusted HR, 0.99 [95% CI, 0.87-1.12]; P=0.873). After unsuccessful CTO PCI, long-term all-cause mortality was higher than non-CTO PCI (unadjusted HR, 1.82 [95% CI, 1.59-2.08], adjusted HR, 1.35 [95% CI, 1.13-1.63]; P<0.001). Conclusions Patients undergoing PCI for CTO have elevated long-term mortality compared with patients without CTO. Successful opening of the CTO(s) is associated with equal mortality compared with non-CTO PCI. In contrast, failed CTO PCI is associated with worse long-term mortality. These findings suggest the need for CTO programs with high success rates and low complication rates.

Early healing after treatment of coronary lesions by thin strut everolimus, or thicker strut biolimus eluting bioabsorbable polymer stents: The SORT-OUT VIII OCT study.

AIMS: Early healing after drug-eluting stent (DES) implantation may reduce the risk of stent thrombosis. The aim of this study was to compare patterns of early healing after implantation of the thin strut everolimus-eluting Synergy DES (Boston Scientific) or the biolimus-eluting Biomatix Neoflex DES (Biosensors). METHODS AND RESULTS: A total of 160 patients with the chronic or acute coronary syndrome were randomized 1:1 to Synergy or Biomatrix DES. Optical coherence tomography (OCT) was performed at baseline and at either 1- or 3-month follow-up. The primary endpoint was a coronary stent healing index (CSHI), a weighted index of strut coverage, neointimal hyperplasia, malapposition, and extrastent lumen. A total of 133 cases had OCT follow-up and 119 qualified for matched OCT analysis. The median CSHI score did neither differ significantly between the groups at 1 month: Synergy 8.0 (interquartile range [IQR]: 3.0; 14.0) versus Biomatrix 8.5 (IQR: 4.0; 15.0) (p = 0.47) nor at 3 months: Synergy 6.5 (IQR: 2.0; 13.0) versus Biomatrix 6.0 (IQR: 4.0; 11.0) (p = 0.83). Strut coverage was 84.6% (IQR: 72.0; 97.9) for Synergy versus 77.6% (IQR: 70.1; 90.3) for Biomatrix (p = 0.15) at 1 month and 90.3% (IQR 79.0; 98.8) (Synergy) versus 83.9% (IQR: 77.5; 92.6) (Biomatrix) (p = 0.068) at 3 months. Pooled 1- and 3-month coverage was 88.6% (IQR: 74.4; 98.4) for Synergy compared with 80.7% (IQR: 73.2; 90.8) for Biomatrix (p = 0.02). CONCLUSIONS: The early healing response after treatment with the Synergy or Biomatrix DES did not differ significantly as determined by a healing index. The Synergy DES showed overall better early stent strut coverage.

Bioresorbable magnesium scaffold in the treatment of simple coronary bifurcation lesions: The BIFSORB pilot II study.

OBJECTIVES: To evaluate the feasibility, safety, and healing response of a magnesium-based bioresorbable scaffold (BRS) in the treatment of simple bifurcation lesions using the single stent provisional technique. BACKGROUND: BRS may hold potential advantages in the treatment of coronary bifurcation lesions, however low radial strength and expansion capacity has been an issue with polymer-based scaffolds. The magnesium BRS may prove suitable for bifurcation treatment as its mechanical properties are closer to those of permanent metallic drug-eluting stents. METHODS: The study was a proof-of-concept study with planned inclusion of 20 patients with stable angina pectoris and a bifurcation lesion involving a large side branch (SB) > 2.5 mm with less than 50% diameter stenosis. Procedure and healing response were evaluated by optical coherence tomography (OCT). The main endpoints were a composite clinical safety endpoint and an OCT healing index at 1 month (range: 0-98). RESULTS: Eleven patients were included in the study. The study was prematurely terminated due to scaffold fractures and embolization of scaffold fragments in three cases requiring bailout stenting with drug-eluting stents. One patient underwent bypass surgery at 3 months due to stenosis proximal to the study segment. All SB were patent for 1 month. One-month OCT evaluation showed strut coverage of 96.9% and no malapposition. Scaffold fractures and uncovered jailing struts resulted in a less favorable mean OCT healing index score of 10.4 ± 9.0. CONCLUSIONS: Implanting a magnesium scaffold by the provisional technique in nontrue bifurcation lesions was associated with scaffold fracture, embolization of scaffold fragments, and a high need for bailout stenting.

Effects of local hemodynamics and plaque characteristics on neointimal response following bioresorbable scaffolds implantation in coronary bifurcations.

Heterogeneous neointimal response has been observed after implantation of all generations of coronary stents. Our aim was assessing local factors of shear stress (SS) and plaque characteristics in neointimal response after implantation of bioresorbable scaffolds (BRS) in bifurcations. Ten patients from the BIFSORB pilot study were analysed. Follow-up optical frequency domain imaging (OFDI) was performed at 1 month and 2 years. Coronary lumen and BRS structure were reconstructed by fusion of OFDI and angiography and were used for subsequent flow simulation. Plaque arc degree and SS were quantified using post-procedural OFDI data and were matched with follow-up OFDI using anatomical landmarks. Strut-level and segment-level analysis were performed for 1-month and 2-year follow-up respectively. A total of 444 struts (54 jailing struts) were included at 1-month follow-up. Time-average SS (TASS) was significantly lower for covered struts than for uncovered struts in non-bifurcation segments (TASS: 1.81 ± 1.87 vs. 3.88 ± 3.72 Pa, p < 0.001). The trend remained the same for jailing struts, although statistically insignificant (TASS: 10.85 ± 13.12 vs. 13.64 ± 14.48 Pa, p = 0.328). For 2-year follow-up, a total of 66 sub-regions were analysed. Neointimal hyperplasia area (NTA) was negatively correlated with TASS in core-segments (ρ = - 0.389, p = 0.037) and positively correlated with plaque arc degree in non-core segments (ρ = 0.387, p = 0.018). Slightly stronger correlations with NTA were observed when combining TASS and plaque arc degree in both core segments (ρ = - 0.412, p = 0.026) and non-core segments (ρ = - 0.395, p = 0.015). Hemodynamic microenvironment and baseline plaque characteristics may regulate neointimal response after BRS implantation in bifurcation. These findings underline the combined role of plaque characteristics and local hemodynamics in vessel healing after stent implantation.

Local Flow Patterns After Implantation of Bioresorbable Vascular Scaffold in Coronary Bifurcations　- Novel Findings by Computational Fluid Dynamics.

BACKGROUND: Development of methods for accurate reconstruction of bioresorbable scaffolds (BRS) and assessing local hemodynamics is crucial for investigation of vascular healing after BRS implantation.Methods and Results:Patients with BRS that crossed over in a coronary bifurcation were included for analysis. Reconstructions of the coronary lumen and BRS were performed by fusion of optical coherence tomography and coronary angiography generating a tree model (TM) and a hybrid model with BRS (TM-BRS). A virtual BRS model with thinner struts was created and all 3 models were analyzed using computational fluid dynamics to derive: (1) time-average shear stress (TASS), (2) TASS gradient (TASSG), which represents SS heterogeneity, and (3) fractional flow reserve (FFR). Reconstruction of the BRS was successful in all 10 patients. TASS and TASSG were both higher by TM-BRS than by TM in main vessels (difference 0.27±4.30 Pa and 10.18±27.28 Pa/mm, P<0.001), with a remarkable difference at side branch ostia (difference 13.51±17.40 Pa and 81.65±105.19 Pa/mm, P<0.001). With thinner struts, TASS was lower on the strut surface but higher at the inter-strut zones, whereas TASSG was lower in both regions (P<0.001 for all). Computational FFR was lower by TM-BRS than by TM for both main vessels and side branches (P<0.001). CONCLUSIONS: Neglecting BRS reconstruction leads to significantly lower SS and SS heterogeneity, which is most pronounced at side branch ostia. Thinner struts can marginally reduce SS heterogeneity.