Browsing by Subject "Carotid Stenosis"

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    Association of Transcarotid Artery Revascularization vs Transfemoral Carotid Artery Stenting With Stroke or Death Among Patients With Carotid Artery Stenosis
    (American Medical Association, 2019-12-17) Schermerhorn, Marc L.; Liang, Patric; Eldrup-Jorgensen, Jens; Cronenwett, Jack L.; Nolan, Brian W.; Kashyap, Vikram S.; Wang, Grace J.; Motaganahalli, Raghu L.; Malas, Mahmoud B.; Surgery, School of Medicine
    Importance: Several trials have observed higher rates of perioperative stroke following transfemoral carotid artery stenting compared with carotid endarterectomy. Transcarotid artery revascularization with flow reversal was recently introduced for carotid stenting. This technique was developed to decrease stroke risk seen with the transfemoral approach; however, its outcomes, compared with transfemoral carotid artery stenting, are not well characterized. Objective: To compare outcomes associated with transcarotid artery revascularization and transfemoral carotid artery stenting. Design, setting, and participants: Exploratory propensity score-matched analysis of prospectively collected data from the Vascular Quality Initiative Transcarotid Artery Surveillance Project and Carotid Stent Registry of asymptomatic and symptomatic patients in the United States and Canada undergoing transcarotid artery revascularization and transfemoral carotid artery stenting for carotid artery stenosis, from September 2016 to April 2019. The final date for follow-up was May 29, 2019. Exposures: Transcarotid artery revascularization vs transfemoral carotid artery stenting. Main outcomes and measures: Outcomes included a composite end point of in-hospital stroke or death, stroke, death, myocardial infarction, as well as ipsilateral stroke or death at 1 year. In-hospital stroke was defined as ipsilateral or contralateral, cortical or vertebrobasilar, and ischemic or hemorrhagic stroke. Death was all-cause mortality. Results: During the study period, 5251 patients underwent transcarotid artery revascularization and 6640 patients underwent transfemoral carotid artery stenting. After matching, 3286 pairs of patients who underwent transcarotid artery revascularization or transfemoral carotid artery stenting were identified (transcarotid approach: mean [SD] age, 71.7 [9.8] years; 35.7% women; transfemoral approach: mean [SD] age, 71.6 [9.3] years; 35.1% women). Transcarotid artery revascularization was associated with a lower risk of in-hospital stroke or death (1.6% vs 3.1%; absolute difference, -1.52% [95% CI, -2.29% to -0.75%]; relative risk [RR], 0.51 [95% CI, 0.37 to 0.72]; P < .001), stroke (1.3% vs 2.4%; absolute difference, -1.10% [95% CI, -1.79% to -0.41%]; RR, 0.54 [95% CI, 0.38 to 0.79]; P = .001), and death (0.4% vs 1.0%; absolute difference, -0.55% [95% CI, -0.98% to -0.11%]; RR, 0.44 [95% CI, 0.23 to 0.82]; P = .008). There was no statistically significant difference in the risk of perioperative myocardial infarction between the 2 cohorts (0.2% for transcarotid vs 0.3% for the transfemoral approach; absolute difference, -0.09% [95% CI, -0.37% to 0.19%]; RR, 0.70 [95% CI, 0.27 to 1.84]; P = .47). At 1 year using Kaplan-Meier life-table estimation, the transcarotid approach was associated with a lower risk of ipsilateral stroke or death (5.1% vs 9.6%; hazard ratio, 0.52 [95% CI, 0.41 to 0.66]; P < .001). Transcarotid artery revascularization was associated with higher risk of access site complication resulting in interventional treatment (1.3% vs 0.8%; absolute difference, 0.52% [95% CI, -0.01% to 1.04%]; RR, 1.63 [95% CI, 1.02 to 2.61]; P = .04), whereas transfemoral carotid artery stenting was associated with more radiation (median fluoroscopy time, 5 minutes [interquartile range {IQR}, 3 to 7] vs 16 minutes [IQR, 11 to 23]; P < .001) and more contrast (median contrast used, 30 mL [IQR, 20 to 45] vs 80 mL [IQR, 55 to 122]; P < .001). Conclusions and relevance: Among patients undergoing treatment for carotid stenosis, transcarotid artery revascularization, compared with transfemoral carotid artery stenting, was significantly associated with a lower risk of stroke or death.
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    Ras-Mek-Erk Signaling Regulates Nf1 Heterozygous Neointima Formation
    (Elsevier B.V., 2014-01) Stansfield, Brian K.; Bessler, Waylan K.; Mali, Raghuveer; Mund, Julie A.; Downing, Brandon D.; Kapur, Reuben; Ingram, David A. Jr; Department of Pediatrics, IU School of Medicine
    Neurofibromatosis type 1 (NF1) results from mutations in the NF1 tumor-suppressor gene, which encodes neurofibromin, a negative regulator of diverse Ras signaling cascades. Arterial stenosis is a nonneoplastic manifestation of NF1 that predisposes some patients to debilitating morbidity and sudden death. Recent murine studies demonstrate that Nf1 heterozygosity (Nf1+/−) in monocytes/macrophages significantly enhances intimal proliferation after arterial injury. However, the downstream Ras effector pathway responsible for this phenotype is unknown. Based on in vitro assays demonstrating enhanced extracellular signal-related kinase (Erk) signaling in Nf1+/− macrophages and vascular smooth muscle cells and in vivo evidence of Erk amplification without alteration of phosphatidylinositol 3-kinase signaling in Nf1+/− neointimas, we tested the hypothesis that Ras-Erk signaling regulates intimal proliferation in a murine model of NF1 arterial stenosis. By using a well-established in vivo model of inflammatory cell migration and standard cell culture, neurofibromin-deficient macrophages demonstrate enhanced sensitivity to growth factor stimulation in vivo and in vitro, which is significantly diminished in the presence of PD0325901, a specific inhibitor of Ras-Erk signaling in phase 2 clinical trials for cancer. After carotid artery injury, Nf1+/− mice demonstrated increased intimal proliferation compared with wild-type mice. Daily administration of PD0325901 significantly reduced Nf1+/− neointima formation to levels of wild-type mice. These studies identify the Ras-Erk pathway in neurofibromin-deficient macrophages as the aberrant pathway responsible for enhanced neointima formation.