Chronic total occlusion, in-stent restenosis, thrombotic, calcific lesions >40 mm, and atherosclerotic lesions >140 mm identified by peripheral angiography necessitate concomitant filter use during atherectomy to prevent embolic complications.
Background and aims
Neointimal cellular proliferation of fibroblasts and myofibroblasts is documented in coronary artery restenosis, however, their role in peripheral arterial disease (PAD) restenosis remains unclear. Our aim was to investigate the role of fibroblasts, myofibroblasts, and collagens in restenotic PAD.
Methods
Nineteen PAD restenotic plaques were compared with 13 de novo plaques. Stellate cells (H&E), fibroblasts (FSP-1), myofibroblasts (α-actin/vimentin/FSP-1), cellular proliferation (Ki-67), and apoptosis (caspase-3 with poly ADP-ribose polymerase) were evaluated by immunofluorescence. Collagens were evaluated by picro-sirius red stain with polarization microscopy. Smooth muscle myosin heavy chain (SMMHC), IL-6 and TGF-β cytokines were analyzed by immunohistochemistry.
Results
Restenotic plaques demonstrated increased stellate cells (2.7 ± 0.15 vs. 1.3 ± 0.15) fibroblasts (2282.2 ± 85.9 vs. 906.4 ± 134.5) and myofibroblasts (18.5 ± 1.2 vs. 10.6 ± 1.0) p = 0.0001 for all comparisons. In addition, fibroblast proliferation (18.4% ± 1.2 vs. 10.4% ± 1.1; p = 0.04) and apoptosis (14.6% ± 1.3 vs. 11.2% ± 0.6; p = 0.03) were increased in restenotic plaques. Finally, SMMHC (2.6 ± 0.12 vs. 1.4 ± 0.15; p = 0.0001), type III collagen density (0.33 ± 0.06 vs. 0.17 ± 0.07; p = 0.0001), IL-6 (2.08 ± 1.7 vs. 1.03 ± 2.0; p = 0.01), and TGF-β (1.80 ± 0.27 vs. 1.11 ± 0.18; p = 0.05) were increased in restenotic plaques.
Conclusions
Our study suggests proliferation and apoptosis of fibroblast and myofibroblast with associated increase in type III collagen may play a role in restenotic plaque progression. Understanding pathways involved in proliferation and apoptosis in neointimal cells, may contribute to future therapeutic interventions for the prevention of restenosis in PAD.
Objective—
Haptoglobin (Hp) protein is responsible for hemoglobin clearance after intra-plaque hemorrhage. Hp gene exists as Hp-1 and Hp-2 alleles and the phenotypes show important molecular heterogeneity. We tested the hypothesis that hemoglobin clearance may be deficient in diabetic atheroma from patients with Hp2-2, triggering increased oxidative, inflammatory, and angiogenic patterns compared with controls.
Methods and Results—
Forty patients with diabetes mellitus were genotyped and their peripheral plaques compared after atherectomy. Plaque hemorrhage, iron content, hemoglobin-binding protein CD163, and heme-oxygenase-1 were quantified. Oxidative, inflammatory, and angiogenic patterns were evaluated by measuring myeloperoxidase, interleukin-10, macrophages, vascular cell adhesion molecule-1, smooth muscle actin, and plaque neovascularization (CD34/CD31). Plaques with Hp2-2 (n=7) had increased hemorrhage (
P
<0.005), iron content (
P
<0.001), and reduced CD163 expression (
P
<0.002) compared with controls (n=14). Hp2-2 plaques had increased heme-oxygenase-1 protein (
P
<0.02), myeloperoxidase gene (
P
<0.05), and protein (
P
<0.0001). Anti-inflammatory interleukin-10 gene (
P
<0.04), and protein expressions (
P
<0.0001) were decreased in Hp2-2. Finally, macrophage (
P
<0.0001), vascular cell adhesion molecule-1 (
P
=0.001), smooth muscle actin (
P
=0.002) scores, and neovessels density (
P
<0.0001) were increased in Hp2-2.
Conclusion—
Genotype-dependent impairment of hemoglobin clearance after intra-plaque hemorrhage is associated with increased oxidative, inflammatory, and angiogenic response in human diabetic atherosclerosis.
Diabetes mellitus (DM) and chronic kidney disease (CKD) separately are known to facilitate the progression of medial arterial calcification (MAC) in patients with symptomatic peripheral artery disease (PAD), but their combined effect on MAC and associated mediators of calcification is not well studied. The association of MAC and calcification inducer bone morphogenetic protein (BMP-2) and inhibitor fetuin-A, with PAD, is well known. Our aim was to investigate the association of MAC with alterations in BMP-2 and fetuin-A protein expression in patients with PAD with DM and/or CKD. Peripheral artery plaques (50) collected during directional atherectomy from symptomatic patients with PAD were evaluated, grouped into no-DM/no-CKD ( n = 14), DM alone ( n = 10), CKD alone ( n = 12), and DM+CKD ( n = 14). MAC density was evaluated using hematoxylin and eosin, and alizarin red stain. Analysis of inflammation, neovascularization, BMP-2 and fetuin-A protein density was performed by immunohistochemistry. MAC density, inflammation grade and neovessel content were significantly higher in DM+CKD versus no-DM/no-CKD and CKD ( p < 0.01). BMP-2 protein density was significantly higher in DM+CKD versus all other groups ( p < 0.01), whereas fetuin-A protein density was significantly lower in DM+CKD versus all other groups ( p < 0.001). The combined presence of DM+CKD may be associated with MAC severity in PAD plaques more so than DM or CKD alone, as illustrated in this study, where levels of calcification mediators BMP-2 and fetuin-A protein were related most robustly to DM+CKD. Further understanding of mechanisms involved in mediating calcification and their association with DM and CKD may be useful in improving management and developing therapeutic interventions.
We assessed the clinical outcomes of patients with critical limb-threatening ischemia (CLTI) who underwent interwoven nitinol stent (Supera) implantation for significant stenoses of the femoropopliteal segment. In this retrospective cohort study, 116 consecutive patients with CLTI who were treated with Supera stents between September 2015 and March 2020 were included in this analysis. Primary endpoint analysis was completed for amputation-free survival, target lesion revascularization (TLR), and mortality. After a mean follow-up time of 3.4 years, 21 (18%) patients had undergone amputations, 3 (2.6%) died, and, overall, the amputation-free survival rate was 81%. TLR occurred in 21 (18%) patients, resulting in the freedom from target lesion revascularization of 82%. The average Wagner score for all patients was 2.8 ± 1.1. A subgroup analysis of 57 patients revealed a median ulcer size of 3.0 cm2 [1.65, 9.0], with complete healing for 45 patients by 20 months. The Wagner score of this subgroup decreased by an average of 3.4 ± .9 points. Supera stents can be used together with other endovascular therapies and are a safe and effective treatment modality for CLTI.
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