Meta-Analysis of Anticoagulation Therapy for the Prevention of Cardiovascular Events in Patients With Peripheral Arterial Disease.

Peripheral artery disease (PAD) remains a major cause of morbidity and future cardiovascular events despite advancement in the surgical interventions and optimal medical therapy. The aim of our study is to evaluate the efficacy and safety of anticoagulation (AC) therapy for reducing cardiovascular and limb events in patients with PAD. PUBMED, Medline, and Cochrane Library were searched through 2020 for randomized clinical trials comparing major adverse cardiovascular events (MACE) and risk of major bleeding (MB), between AC and standard of care (SOC) therapy, among patients with PAD. Meta-analysis was performed using weighted pooled absolute risk difference (RD) with 95% confidence interval (CI) and fixed effects model for overall and sub-groups of full dose (FD) and low dose (LD) AC therapies. Amongst 17,684 patients from 7 different studies, the addition of AC to SOC therapy was associated with MACE reduction (RD -0.022, 95% CI -0.033 to -0.012, p <0.001) and increased MB (RD 0.02, 95% CI 0.014 to 0.025, p <0.001). For FD, MACE reduction was (RD -0.021, 95% CI -0.042 to 0.001, p = 0.061) and MB (RD 0.036, 95% CI 0.025 to 0.047, p <0.001). For LD, MACE reduction was (RD -0.023, 95% CI -0.035 to -0.011, p <0.001) and MB (RD 0.011, 95% CI 0.005 to 0.017, p <0.001). In conclusion, addition of AC to the current SOC therapy can mitigate future MACE events in patients with PAD albeit at risk of increased bleeding. LD AC is associated with an efficacy/safety net benefit compared to FD AC therapy.

Intravascular ultrasound guided directional atherectomy versus directional atherectomy guided by angiography for the treatment of femoropopliteal in-stent restenosis.

BACKGROUND: The aim of this study was to compare 1-year outcomes for patients with femoropopliteal in-stent restenosis using directional atherectomy guided by intravascular ultrasound (IVUS) versus directional atherectomy guided by angiography. METHODS AND RESULTS: This was a retrospective analysis for patients with femoropopliteal in-stent restenosis treated with IVUS-guided directional atherectomy versus directional atherectomy guided by angiography from a single center between March 2012 and February 2016. Clinically driven target lesion revascularization was the primary endpoint and was evaluated through medical chart review as well as phone call follow up. CONCLUSIONS: Directional atherectomy guided by IVUS reduces clinically driven target lesion revascularization for patients with femoropopliteal in-stent restenosis.

Enhanced neointimal fibroblast, myofibroblast content and altered extracellular matrix composition: Implications in the progression of human peripheral artery restenosis.

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-ß 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-ß (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.