Vascular Medicine

Patients with fibromuscular dysplasia (FMD) may have clinical features consistent with Mendelian vascular connective tissue disorders. The yield of genetic testing for these disorders among patients with FMD has not been determined. A total of 216 consecutive patients with FMD were identified. Clinical characteristics were collected and genetic test results reviewed for abnormalities in the following genes: transforming growth factor-β receptor 1 and 2 (TGFβR1 and TGFβR2), collagen 3A1, fibrillin-1, smooth muscle α-actin 2, and SMAD3. A total of 63 patients (63/216; 29.2%) were referred for genetic counseling with testing performed in 35 (35/63; 55.6%). The percentage of patients with a history of arterial or aortic dissection, history of aortic aneurysm, systemic features of a connective tissue disorder, and a family history of sudden death was significantly larger in the group that underwent genetic testing (62.9% vs 18.2%, p < 0.001; 8.6% vs 1.7%, p = 0.02; 51.4% vs 17.1%, p < 0.001; and 42.9% vs 22.7%, p = 0.04, respectively). Two patients were found to have distinct variants in the TGFβR1 gene (c.611 C>T, p.Thr204lle and c.1285 T>C, p.Tyr429His). The yield of genetic testing for vascular connective tissue disorders was low in a high-risk subset of FMD patients. However, two patients with a similar phenotype had novel and distinct variants in the TGFβR1 gene, a finding which merits further investigation.

Resuscitation from hemorrhagic shock induces endothelial dysfunction and activates inflammatory cascades leading to organ damage. Following restoration of blood flow to ischemic vascular beds, leukocyte–endothelium interactions leading to leukocyte infiltration into the vascular wall occur very early due, in part, to the loss of endothelium-derived nitric oxide (NO). The mechanism by which ischemia–reperfusion injury impairs endothelium-derived NO is not completely understood. We hypothesized that inhibition of Rho-kinase could exert beneficial effects following hemorrhagic shock by preserving endothelial function and attenuating leukocyte trafficking in the microcirculation. Using intravital microscopy, we found that resuscitation from hemorrhage acutely increased the number of rolling and adherent leukocytes in the mouse splanchnic microcirculation. Treatment of mice with the Rho-kinase inhibitor fasudil, markedly attenuated leukocyte–endothelium interaction in response to hemorrhage/reinfusion. The beneficial effect of fasudil was not observed in endothelial nitric oxide synthase (eNOS)^−/− mice. In conclusion, inhibition of Rho-kinase prevents inflammatory leukocyte trafficking in the microcirculation via an eNOS-dependent mechanism. Our data support a role for Rho-kinase inhibitors in the treatment of ischemia–reperfusion injury.

Current guidelines recommend obtaining an ankle–brachial index (ABI) to screen for peripheral artery disease (PAD) in subjects at risk. Previous work demonstrated that a combination of β₂-microglobulin, cystatin C, high-sensitivity C-reactive protein and glucose was associated with PAD. This study evaluated the ability of these biomarkers combined with clinical parameters to predict PAD in at-risk subjects. This study enrolled 1025 subjects from 99 primary care clinics who were smokers and/or diabetics ≥ 50 years or any individual ≥ 70 years. Consented subjects underwent a clinical assessment, fasting blood draw, and an ABI measurement with PAD defined as an ABI < 0.90 in either leg. The biomarkers and their interactions were evaluated using logistic regression and performance was evaluated at a cut point of the biomarker panel selected to maximize sensitivity while minimizing the false positive rate of the test. Of the 1025 subjects enrolled, 46 did not meet the ABI or other criteria for inclusion in the analysis. Among the evaluable subjects (n = 979), PAD was detected in 83 (8.5%). The model had a C-statistic of 0.73 (95% CI 0.67–0.79). There were 20 patients with PAD who were judged to be at low to moderate risk for cardiovascular events by clinical assessment; the model correctly identified 17 of these 20 patients. The model also performed well in subjects with no prior history of PAD. Thus, a biomarker panel may have a role for identifying PAD.

Adequate vitamin D levels may promote cardiovascular health by improving endothelial function and down-regulating inflammation. The objective of this pilot trial was to investigate the effects of vitamin D repletion on endothelial function and inflammation in patients with coronary artery disease (CAD). Using a double-blind placebo wait-list control design, 90 subjects with CAD and vitamin D deficiency (< 20 ng/ml) were randomized 1:1 to 50,000 IU of oral ergocalciferol or placebo weekly for 12 weeks. Endothelial function (reactive hyperemia peripheral arterial tonometry, RH-PAT), circulating adhesion molecules, and pro-inflammatory cytokines were measured at baseline and 12 weeks. The median increase in serum 25-vitamin D from baseline was 26 ± 17 ng/ml in the active group and 4 ± 8 ng/ml in the placebo group (between-group difference = 22 ng/ml, p < 0.001). The median within-subject change in RH-PAT score was 0.13 ± 0.73 with active treatment and −0.04 ± 0.63 with placebo (between-group difference = 0.17, p = 0.44). Within-group and between-group differences in intercellular adhesion molecule levels were greater with placebo (between-group difference = 6 ng/ml, p = 0.048). Vascular cell adhesion molecule levels decreased in both groups by a similar magnitude (median difference between groups = 8.5 ng/ml, p = 0.79). There was no difference between groups in magnitude of reduction in interleukin (IL)-12 (−8.6 ng/ml, p = 0.72) and interferon-gamma (0.52 ng/ml, p = 0.88). No significant differences in blood pressure, e-selectin, high-sensitivity c-reactive protein, IL-6 or the chemokine CXCL-10 were found with treatment. In conclusion, repleting vitamin D levels in subjects with CAD failed to demonstrate any benefits on surrogate markers of cardiovascular health. These results question the role of vitamin D supplementation in modifying cardiovascular disease.

Understanding the impact of peripheral artery disease (PAD) requires broad evaluation of how functional limitations of PAD affect patients’ perceptions of health-related quality of life (HRQL). The objective of this study was to describe the development, testing, and psychometric properties of the PAD Quality of Life Questionnaire (PADQOL). The PADQOL was developed in three steps: (1) interviews of symptomatic PAD patients provided content of the initial questionnaire; (2) co-administration with the SF-36 (a 36-item short-form health survey), Walking Impairment Questionnaire, and Profile of Mood States examined construct validity; and (3) a three-phased factor analysis identified factors and shortened the questionnaire. Data analyses from 297 symptomatic PAD patients resulted in a 38-item questionnaire of five factors: Social relationships and interactions, Self-concept and feelings, Symptoms and limitations in physical functioning, Fear and uncertainty, and Positive adaptation (α = 0.92–0.73) and items related to sexual function, intimate relationships and employment. Between-instrument correlations established construct validity. In conclusion, PADQOL is a validated measure to assess the disease-specific physical, psychosocial and emotional effects of PAD for research and practice.

Dimethylarginine dimethyl-aminohydrolase 1 (DDAH1) is a metabolic enzyme for asymmetric dimethylarginine (ADMA), both of which are closely related to endothelial function. Endothelial dysfunction, a main risk factor of cardiovascular diseases, can be attributed to insulin resistance. We aimed to determine the effects of atorvastatin, an endothelium-protective drug, on DDAH1/ADMA in insulin-resistant rats. Insulin resistance in male Sprague-Dawley rats was induced with a high-fat diet for 8 weeks. Some rats received atorvastatin (30 mg/kg/day) for an additional 8 weeks. Insulin-resistant rats exhibited not only decreases in the DDAH activity and aortic expression of DDAH1 and sterol regulatory element-binding protein 1 (SREBP1) but also increases in plasma ADMA levels, all of which were inhibited by atorvastatin. Insulin sensitivity and DDAH activity showed a significant positive correlation. In conclusion, our results suggest that atorvastatin may modulate DDAH1/ADMA to improve endothelial function in insulin-resistant rats; SREBP1 may also play a role in this.

Aortic dissection occurring in the infrarenal abdominal aorta is uncommon. We present the case of a patient presenting with an enlarging abdominal aortic aneurysm and concurrent dissection (with associated radiological imaging) and briefly discuss the literature relating to this phenomenon.