Peter Klein-Weigel

High Prevalence of Circulating CD4 + CD28 − T-Cells in Patients With Small Abdominal Aortic Aneurysms

Objective—To assess the possible role of proinflammatory CD28− T cells in abdominal aortic aneurysms (AAAs). Animal studies and human tissue studies suggest a role for interferon (IFN)-γ–producing T cells in the development and progression of AAAs. Methods and Results—Fluorescence-activated cells sorter analysis of peripheral blood samples and measurement of AAA size using sonography were performed in 101 AAA patients and 38 healthy controls. Peripheral percentages of CD28− T cells of the CD3+CD4+ and the CD3+CD8+ were enriched in AAA patients with 7.8±8.8% and 41.9±15.7% compared with healthy controls with 2.2±6.1% and 24.9±15.5%, respectively (P=0.002 and P<0.001, respectively). Both CD4+CD28− and CD8+CD28− T cells produced large amounts of IFN-γ and perforin. Patients with small AAAs (<4 cm) showed higher peripheral levels of CD4+CD28− T cells than those with larger AAAs (P=0.025). Immunohistological examinations revealed 39.1±17.2% CD4+CD28− and 44.0±13.8% CD8+CD28− in AAA tissue specimens with inflammatory infiltrates. Conclusions—IFN-γ– and perforin-producing CD28− T cells are present in the periphery and the vessel wall of a majority of AAAs. This observation in humans favors the concept of a T cell–mediated pathophysiology of AAAs, especially during the early development of AAAs.

Association between the UGT1A1 TA-Repeat Polymorphism and Bilirubin Concentration in Patients with Intermittent Claudication: Results from the CAVASIC Study

BACKGROUND Bilirubin has antioxidative and cytoprotective properties. Low plasma concentrations of bilirubin are reportedly associated with the development of coronary and cerebrovascular disease, and bilirubin concentrations are strongly correlated with the enzyme activity of the hepatic uridine diphosphate glucuronosyltransferase (UGT1A1). The activity of UGT1A1 is influenced by a TA-repeat polymorphism in the promoter of the UGT1A1 gene (UDP glucuronosyltransferase 1 family, polypeptide A1). In a case-control study, we investigated the association between the UGT1A1 polymorphism, bilirubin concentration, and intermittent claudication. METHODS We included 255 consecutive male patients presenting with intermittent claudication in the investigation and matched the patients by age and diabetes mellitus with 255 control individuals. RESULTS Plasma bilirubin concentrations were significantly lower in patients than in controls [mean (SD), 12.5 (5.3) micromol/L vs 15.4 (7.9) micromol/L; P < 0.001]. We found a clear association between the number of TA repeats and plasma bilirubin concentration. Considering the 6/6 TA-repeat genotype as the wild type, we observed a slight increase in bilirubin concentration individuals with the heterozygous 6/7 genotype and pronounced increases for those with the homozygous 7/7 genotype. This association occurred in both controls and patients; however, patients and controls were not significantly different with respect to UGT1A1 TA-repeat genotype frequencies. CONCLUSIONS Our study of a well-phenotyped group of patients with intermittent claudication and control individuals revealed a clear association between low bilirubin concentrations and peripheral arterial disease but no association between the UGT1A1 polymorphism and the disease.

The association of relative telomere length with symptomatic peripheral arterial disease: Results from the CAVASIC study

BACKGROUND AND OBJECTIVES Short telomere length has been described to be associated with biological aging including atherosclerosis phenotypes. However, information in patients with symptomatic peripheral arterial disease (PAD) is sparse. We therefore aimed to investigate whether inter-individual differences in relative telomere length (RTL) are associated with symptomatic PAD. DESIGN We measured RTL by a quantitative PCR method in the CAVASIC Study, a cohort of 241 male Caucasian patients diagnosed with intermittent claudication and 249 age- and diabetes-matched controls. RESULTS We observed significantly shorter mean RTL in patients than in controls (1.24 ± 0.19 vs. 1.32 ± 0.23, p < 0.001). Each shortening of RTL by one standard deviation significantly increased the odds for PAD by 44%: age-adjusted OR = 1.44 (95%CI 1.19-1.75, p < 0.001). This association remained significant after additional adjustment for log-C-reactive protein, glomerular filtration rate, HDL cholesterol, current smoking and log N-terminal pro-B-type natriuretic peptide (NT-proBNP). Excluding patients with prevalent cardiovascular disease revealed very similar results. When we compared the model fit of the various adjustment models including cardiac risk factors and/or NT-proBNP the addition of RTL significantly improved discrimination between patients and controls. CONCLUSION This study in a male cohort of patients with intermittent claudication and age- and diabetes-matched controls indicates a significant association of shorter relative telomere length with PAD. Our results reinforce RTL as a marker for PAD that reflects the influence of genetic and environmental risk factors. Moreover, the association remains significant after excluding patients and controls free from prevalent cardiovascular disease.

Incidence and predisposing factors of cold intolerance after arterial repair in upper extremity injuries

OBJECTIVE The purpose of this report was to present abnormal posttraumatic cold intolerance in patients that previously underwent repair of arterial injuries after civilian upper limb trauma in our institution. METHODS All patients who underwent repair of arterial lesions after upper limb trauma since 1990 were reviewed, and clinical follow-up studies were performed. Patients were asked to complete the cold intolerance symptom severity (CISS) questionnaire to evaluate presence and severity of self-reported cold sensitivity, and the disabilities of arm, shoulder, and hand (DASH) questionnaire to analyze functional disability. Abnormal cold intolerance was defined as a CISS score over 30. Further analysis included evaluation of epidemiologic, clinical, and perioperative data for factors predisposing to abnormal cold intolerance. RESULTS A total of 87 patients with previous repair of upper limb arterial injuries were eligible to answer the CISS and DASH questionnaires, and 56 patients (64%; 43 men; median age: 31.9 years) completed both. In our cohort, blunt trauma was the predominant cause of injury (n = 50; 89%). Accompanying lesions of nerves (n = 22; 39%) and/or orthopedic injuries (n = 36; 64%) were present in 48 patients (86%). After a median follow-up period of 5.5 years (range, 0.5-19.7), 23 patients (41% of 56) reported on abnormal cold intolerance. Patients with cold intolerance had worse functional results (as measured by the DASH questionnaire; mean ± SD, 42.7 ± 29.7 vs 11.5 ± 23.9; P < .001) when compared with patients without. Cold intolerance was more frequently seen in patients with previous nerve lesion (P = .027) and in proximal injuries (subclavian or axillary vs brachial or forearm arteries: P = .006), but was not correlated to gender, age, involvement of the dominant or nondominant arm, and the presence of ischemia, bone injury, or an isolated vascular injury. CONCLUSIONS Abnormal cold intolerance is frequently seen in patients with a history of arterial repair in upper limb trauma. It is associated with significant functional impairment. Concomitant nerve injury and involvement of the subclavian or axillary artery are the major predisposing factors for development of cold intolerance after upper limb trauma.

Systematic screening and treatment evaluation of hereditary neck paragangliomas

Familial paragangliomas of the neck are often bilateral and more aggressive than spontaneous forms. Tumors appear earlier (2nd–4th decade) often with diffuse, multifocal involvement. Without treatment, these tumors can lead to significant morbidity. Three families with succinate dehydrogenase subunit D (SDHD) germline mutations underwent clinical and genetic evaluation. Patients were screened using ultrasound and evaluated further with conventional and functional imaging. Tumors with a diameter >1.5 cm were surgically removed. Multicentric and bilateral tumors were detected in 9/13 (69%) and 8/13 (62%) patients, respectively. Surgical morbidity occurred in 64% of patients. Local recurrence was 57%, although this was lower in tumors with a diameter <2 cm. We recommend an algorithm for a systematic approach to the diagnosis, monitoring, and treatment of familial head and neck paragangliomas. Operative treatment in advanced stages often leads to unwanted morbidity, such that earlier detection and treatment of smaller tumors seems to be of benefit.

Genetic determinants of the ankle-brachial index: A meta-analysis of a cardiovascular candidate gene 50K SNP panel in the candidate gene association resource (CARe) consortium

BACKGROUND Candidate gene association studies for peripheral artery disease (PAD), including subclinical disease assessed with the ankle-brachial index (ABI), have been limited by the modest number of genes examined. We conducted a two stage meta-analysis of ∼50,000 SNPs across ∼2100 candidate genes to identify genetic variants for ABI. METHODS AND RESULTS We studied subjects of European ancestry from 8 studies (n=21,547, 55% women, mean age 44-73 years) and African American ancestry from 5 studies (n=7267, 60% women, mean age 41-73 years) involved in the candidate gene association resource (CARe) consortium. In each ethnic group, additive genetic models were used (with each additional copy of the minor allele corresponding to the given beta) to test each SNP for association with continuous ABI (excluding ABI>1.40) and PAD (defined as ABI<0.90) using linear or logistic regression with adjustment for known PAD risk factors and population stratification. We then conducted a fixed-effects inverse-variance weighted meta-analyses considering a p<2×10(-6) to denote statistical significance. RESULTS In the European ancestry discovery meta-analyses, rs2171209 in SYTL3 (β=-0.007, p=6.02×10(-7)) and rs290481 in TCF7L2 (β=-0.008, p=7.01×10(-7)) were significantly associated with ABI. None of the SNP associations for PAD were significant, though a SNP in CYP2B6 (p=4.99×10(-5)) was among the strongest associations. These 3 genes are linked to key PAD risk factors (lipoprotein(a), type 2 diabetes, and smoking behavior, respectively). We sought replication in 6 population-based and 3 clinical samples (n=15,440) for rs290481 and rs2171209. However, in the replication stage (rs2171209, p=0.75; rs290481, p=0.19) and in the combined discovery and replication analysis the SNP-ABI associations were no longer significant (rs2171209, p=1.14×10(-3); rs290481, p=8.88×10(-5)). In African Americans, none of the SNP associations for ABI or PAD achieved an experiment-wide level of significance. CONCLUSIONS Genetic determinants of ABI and PAD remain elusive. Follow-up of these preliminary findings may uncover important biology given the known gene-risk factor associations. New and more powerful approaches to PAD gene discovery are warranted.

Comparison and Evaluation of Cardiac Biomarkers in Patients with Intermittent Claudication: Results from the CAVASIC Study

BACKGROUND Plasma concentrations of the peptides midregional proadrenomedullin (MR-proADM), midregional proatrial natriuretic peptide (MR-proANP), and C-terminal endothelin-1 precursor fragment (CT-proET-1) are increased in various cardiovascular conditions. However, there is limited information about the association and comparative performance of these peptides in peripheral arterial disease (PAD). METHODS The associations of MR-proADM, MR-proANP, and CT-proET-1 plasma concentrations with symptomatic PAD were investigated in the CAVASIC (Cardiovascular Disease in Intermittent Claudication) Study. Study participants were a male cohort of 238 patients with a diagnosis of intermittent claudication (IC) and 245 age- and diabetes-matched controls. Results were compared to those for N-terminal pro-B-type natriuretic peptide (NT-proBNP). RESULTS Each increase of MR-proADM, MR-proANP, and CT-proET-1 by 1 SD was significantly associated with symptomatic PAD: odds ratio (OR) = 1.78 (95% CI, 1.41-2.25, P < 0.001), OR = 1.32 (95% CI, 1.06-1.66, P = 0.014), and OR = 1.80 (95% CI, 1.43-2.28, P < 0.001), respectively. The association remained significant for all 3 markers after additional adjustment for log C-reactive protein, serum creatinine, HDL cholesterol, and current smoking. When one adjusts for log NT-proBNP and excluding individuals with prevalent cardiovascular disease, MR-proADM and CT-proET-1 still predicted symptomatic PAD. Extended adjustment models including MR-proADM or CT-proET-1 showed significantly improved model fits compared to models including classical cardiac risk factors or NT-proBNP and led to significant reclassification (P < 0.05). CONCLUSIONS This study in a male cohort of patients with IC and age- and diabetes-matched controls indicates a significant association of high MR-proADM, MR-proANP, and CT-proET-1 concentrations with PAD. MR-proADM and CT-proET-1 provide additive information in comparison to NT-proBNP. Moreover, MR-proADM and CT-proET-1 significantly predict PAD in those patients and controls free from prevalent CVD.

Microcirculatory assessment of vascular acrosyndrome in anorexia nervosa and analysis of manifestation factors

OBJECTIVE Acrocyanosis (AC) is a common manifestation of starving syndrome in anorexia nervosa. We characterized microvascular changes associated with AC and determined discriminating factors between acrally symptomatic and nonsymptomatic patients. METHODS We examined 34 patients with anorexia nervosa (15 restrictive-anorectic type, 19 binge-eating/purging type, duration 1-25 years). Nineteen were symptomatic (SP) and 15 were nonsymptomatic (NSP). All underwent photo-pletysmography, sonography of the brachial artery, capillary microscopy and laboratory analysis. RESULTS Disease characteristics and body mass index did not differ between SP and NSP. In SP more dilated efferent capillary loops and venoles were present (P<.001) and capillary flow velocities were reduced (0.21+/-0.12 ml/min vs. 0.34+/-0.15 ml/min; P=.015). Flow-mediated and nitroglycerin-induced dilatation showed no differences. Symptomatic patients had lower leukocyte counts (P=.008), lower eosinophils (P=.003) and lower LDL (P=.045) concentrations. A logistic regression model identified only leukocytes (P=.017) and eosinophils (P=.023) to be associated with AC. CONCLUSIONS In acrally symptomatic patients the typical microvascular features of AC are present. AC is associated with lower leukocyte counts and lower eosinophils.

High-sensitivity cardiac troponin T in patients with intermittent claudication and its relation with cardiovascular events and all-cause mortality – The CAVASIC Study

BACKGROUND Serum concentrations of high-sensitivity cardiac troponin T (hs-cTnT) are elevated in various diseases. The role of this marker in peripheral arterial disease (PAD) has not been fully investigated. METHODS Hs-cTnT was measured in the CAVASIC Study, a male cohort of 235 patients diagnosed with intermittent claudication and 249 age- and diabetes-matched controls. Patients with symptomatic PAD were prospectively followed for a median time of 7 years. The association of hs-cTnT with PAD, cardiovascular disease (CVD) at baseline as well as incident CVD and all-cause mortality during follow-up was analyzed. RESULTS Detectable hs-cTnT was associated with an 84% higher probability for symptomatic PAD at baseline: OR = 1.84, 95%CI 1.05-3.21, p = 0.03. Inclusion of ln-NT-proBNP or prevalent CVD abolished this association (both OR = 1.22, p = 0.52). However, detectable hs-cTnT was associated with prevalent CVD (n = 69) in PAD patients independent from ln-NT-proBNP: OR = 3.42, p = 0.001. In the adjusted Cox regression analysis detectable (HR = 2.15, p = 0.05) and especially hs-cTnT ≥ 14 ng/L (HR = 5.06, p < 0.001) were predictive for all-cause mortality (n = 39) independent from ln-NT-proBNP. Furthermore, hs-cTnT ≥ 14 ng/L was significantly associated with incident CVD (n = 66): HR = 3.15, 95%CI 1.26-7.89, p = 0.01. CONCLUSIONS This study in male patients with intermittent claudication and age- and diabetes-matched controls revealed hs-cTnT to be associated with PAD and prevalent CVD. The latter association was even significant after considering NT-proBNP. Prospectively, in PAD patients hs-cTnT was predictive for incident cardiovascular diseases and all-cause mortality. Thus, hs-cTnT could be a surrogate marker for cardiomyocyte damage also in symptomatic PAD patients.

Left ventricular ejection fraction is associated with prevalent and incident cardiovascular disease in patients with intermittent claudication – results from the CAVASIC Study

BACKGROUND Individuals with an impaired ventricular function have a poor prognosis due to underlying heart failure and higher mortality rates. Patients with peripheral arterial disease (PAD) represent a high-risk population for left ventricular systolic dysfunction (LVSD). METHODS The left ventricular ejection fraction (LVEF) was measured in a subset of the CAVASIC Study, consisting of 180 male patients with intermittent claudication and 226 controls. The patients were prospectively followed for a median time of 7 years. The association of LVEF with PAD and prevalent cardiovascular disease (CVD) as well as with incident CVD and survival rates during follow-up was analyzed. RESULTS The prevalence of LVSD (LVEF<55%) was 30% among PAD patients and 7% among controls (p < 0.001). The adjusted logistic regression analysis showed that a decrease of LVEF by one standard deviation (SD) and an LVEF below 55% was associated with PAD (OR = 1.72, 95%CI 1.30-2.28 and OR = 5.71, 95%CI 2.52-12.95, both p < 0.001). Similar results were found for prevalent CVD (n = 50) in PAD patients: LVEF per SD: OR 1.60; LVEF <55%: OR 2.81, both p ≤ 0.008. The adjustment for ln-NT-proBNP or hs-cTnT resulted in a borderline significant association. In the adjusted Cox regression analysis a decrease of LVEF by one SD showed a trend for association with all-cause mortality (n = 32) (HR 1.27, p = 0.08). An impaired LVEF significantly increased the risk for incident major CVD events (n = 52): HR 1.56, p < 0.01. CONCLUSIONS Patients with PAD have significantly lower LVEF values compared to controls. The LVEF can serve as a risk predictor for subsequent cardiovascular disease among this high-risk population.