Francesco Scopacasa

Endothelial dysfunction in peripheral arterial disease is related to increase in plasma markers of inflammation and severity of peripheral circulatory impairment but not to classic risk factors and atherosclerotic burden

OBJECTIVE We undertook this study to evaluate in patients with peripheral arterial disease (PAD) the relationship of endothelial dysfunction, which is directly related to progression and clinical complications of atherosclerosis, with variables including classic risk factors, inflammation, severity of peripheral circulatory impairment, and atherosclerotic burden. METHODS This cross-sectional study included outpatients seen in an academic angiologic unit. Eighty-eight consecutive patients with PAD (ankle/brachial index [ABI] < 0.90) were studied. The control group consisted of 30 age-matched and sex-matched healthy subjects. Main outcome measures were endothelial function in the form of brachial artery flow-mediated dilation (FMD), plasma levels of C-reactive protein (CRP) and fibrinogen, severity of PAD according to ABI, and atherosclerotic burden, ie, atherosclerosis in one leg or in two or more other sites. RESULTS Compared with patients with FMD greater than 6.2% (ie, 5th percentile of FMD in control subjects), patients with FMD less than 6.2% had a similar prevalence of classic risk factors but higher median levels of CRP (1.6 vs 6.0 mg/L; P <.01) and fibrinogen (200 vs 374 mg/dL; P <.01). The two inflammatory markers were negatively correlated with FMD (P <.01). ABI was higher in patients with FMD greater than 6.2% than in those with worse endothelial function (0.72 +/- 0.15 vs 0.62 +/- 16; P <.01); there was no difference with respect to atherosclerotic burden. Multivariate analysis showed that the association of CRP, fibrinogen, and ABI with FMD less than 6.2% was unrelated to classic risk factors. In a second model, which included CRP, fibrinogen, and ABI, all three variables were independently related to FMD less than 6.2%. CONCLUSION Inflammation and severity of circulatory impairment are implicated in the pathophysiology of dysfunctional endothelium in PAD.

Vitamin C prevents endothelial dysfunction induced by acute exercise in patients with intermittent claudication

In patients with intermittent claudication, exercise is associated with a marked increase in oxidative stress, likely responsible for systemic endothelial perturbation. In 31 claudicant patients, we assessed the effect of vitamin C administration on the acute changes induced by maximal and submaximal exercise in endothelium-dependent, flow-mediated dilation (FMD), and in plasma levels of thiobarbituric acid-reactive substances (TBARS) and soluble intercellular adhesion molecule-1 (sICAM-1). In 16 claudicants, maximal exercise reduced FMD (from 8.5+/-0.9 to 3.7+/-0.8%, P<0.01), and increased plasma levels of TBARS (from 1.93+/-0.06 to 2.22+/-0.1 nmol/ml, P<0.02) and of sICAM-1 (from 282+/-17 to 323+/-19 ng/ml, P<0.01). In eight of these patients, randomized to vitamin C, exercise-induced changes in FMD and biochemistry were abolished. This beneficial effect was not observed in the eight patients randomized to saline. In 15 patients, who walked until the onset of claudication pain (submaximal exercise), and in ten control subjects, who performed maximal exercise, no changes were observed with exercise. Thus, in claudicants, vitamin C prevents the acute, systemic impairment in endothelial function induced by maximal exercise. This finding provides a rationale for trials investigating antioxidant therapy and cardiovascular risk in patients with intermittent claudication.

Could inflammatory markers help diagnose nonalcoholic steatohepatitis

Background Nonalcoholic fatty liver disease describes a set of conditions that range from fatty liver to nonalcoholic steatohepatitis (NASH), and is considered the hepatic manifestation of metabolic syndrome. Obesity and insulin resistance are strongly associated with systemic markers of inflammation. Objective Focusing on this aspect, we have attempted to find a noninvasive method that could likely assess the presence of NASH and help to decide the liver biopsy performance. Methods Using histology as a gold standard to diagnose nonalcoholic fatty liver disease, we consecutively studied 43 patients with NASH and 40 with fatty liver, comparing their data with those of 48 healthy control participants. The outcomes evaluated were ultrasonographic spleen longitudinal diameter coupled with the splenic artery resistive index, serum IL-6 and vascular endothelial growth factor concentrations. Results The NASH group had higher spleen longitudinal diameter values (P=0.0001) as well as significantly higher IL-6 and vascular endothelial growth factor concentrations than the other groups (P=0.0001). The optimal cut-off value for spleen longitudinal diameter that best discriminated NASH from fatty liver patients was 116 mm (specificity 95% and sensitivity 88%); the sensitivity and specificity of this parameter was better than both IL-6 and vascular endothelial growth factor in the same setting (area under the receiver operating characteristic curve 0.920 vs. 0.817 and 0.678). Splenic artery resistive index was similar between patients with NASH and those with fatty liver, but differed when compared with controls, P=0.0001. Conclusions IL-6 was highly specific in confirming the absence of NASH at normal values. In our series, normal values of spleen longitudinal diameter and IL-6 were strongly associated with fatty liver.

Omega-3 polyunsaturated fatty acid in peripheral arterial disease: effect on lipid pattern, disease severity, inflammation profile, and endothelial function.

BACKGROUND & AIMS Peripheral arterial disease (PAD) is strongly associated with endothelial dysfunction and inflammation, which portend a high cardiovascular risk. Accordingly, we investigated the effects of omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation on endothelial function and inflammatory status in affected individuals. METHODS PAD patients were randomly divided into two groups. In Group I (n=16) pre-enrollment therapy was not modified, while in Group II (n=16) n-3 PUFAs 1 g b.i.d. for 3 months were added to the previous treatment. Endothelial function was assessed by measuring plasma soluble thrombomodulin (sTM) and brachial artery flow-mediated dilation (FMD), and the inflammatory status by measuring high-sensitivity C-reactive protein and myeloperoxidase. RESULTS In Group II, n-3 PUFAs reduced sTM levels from the median value of 33.0 ng/mL (interquartile range 16.7, 37.2) to 17.0 ng/mL (11.2, 33.7) (p=0.04), and improved FMD from 6.7% (3.7, 8.7) to 10.0% (6.2, 14.2) (p=0.02). Conversely, these markers did not change in Group I. After 3 months, the levels of inflammatory markers remained unmodified in both groups. CONCLUSIONS In PAD, n-3 PUFAs induced a marked improvement in endothelial function. Conversely, they did not affect the inflammatory status. In future, large, prospective studies are needed to investigate whether n-3 PUFAs, by improving endothelial function, would reduce the incidence of ischemic events in a population at high risk.

Inflammatory status and endothelial function in asymptomatic and symptomatic peripheral arterial disease.

Peripheral arterial disease (PAD) is a predictor of cardiovascular risk. However, it is unknown whether PAD severity influences inflammatory status and endothelial function, which play a major role in atherosclerosis. Accordingly, we measured brachial artery flow-mediated dilation (FMD), and plasma levels of several inflammatory markers in 15 control subjects, and 19 asymptomatic and 19 symptomatic PAD patients. Each symptomatic patient was matched to an asymptomatic patient for age, sex, risk factors, presence of cardiovascular disease, and pharmacological treatments. Asymptomatic patients had similar inflammatory profiles as controls, but lower median FMD (11.7% vs 8.5%, p < 0.01). Compared with asymptomatic patients, symptomatic patients had higher median C-reactive protein (1.5mg=l vs 6.0 mg=l, p < 0.05) and interleukine-6 (1.5 pg=ml vs 3.5 pg=ml, p < 0.05), and lower FMD (8.5% vs 5.1%, p < 0.01). In the 38 PAD patients, the ankle=brachial pressure index correlated positively with FMD (p < 0.01), and negatively with C-reactive protein (p < 0.05), soluble intercellular adhesion molecule-1 (p < 0.05) and soluble vascular cell adhesion molecule-1 (p < 0.05). Thus, in PAD, endothelial function and inflammatory status are related to the severity of the circulatory impairment. This finding may contribute to the explanation of the increasingly poor prognosis with increased PAD severity.

Impact of Diabetes on Cardiac Sympathetic Innervation in Patients With Heart Failure: A 123I meta-iodobenzylguanidine (123I MIBG) scintigraphic study

OBJECTIVE Impaired parasympathetic and sympathetic nervous system activity have been demonstrated in patients with diabetes mellitus (DM) and correlated with worse prognosis. Few data are available on the effect of DM on cardiac neuropathy in heart failure (HF). The aim of the current study was to assess cardiac sympathetic activity in HF patients with and without DM. RESEARCH DESIGN AND METHODS Patients with severe HF (n = 75), with (n = 37) and without DM (n = 38), and 14 diabetic patients with normal cardiac function underwent 123I meta-iodobenzylguanidine scintigraphy from which early and late heart-to-mediastinum (H/M) ratios were calculated. Clinical, echocardiographic, and biochemical data were measured. RESULTS DM compared with non-DM patients showed significantly lower early (1.65 ± 0.21 vs. 1.75 ± 0.21; P < 0.05) and late H/M ratios (1.46 ± 0.22 vs. 1.58 ± 0.24; P < 0.03). Early and late H/M were significantly higher in DM patients without HF (2.22 ± 0.35 and 1.99 ± 0.24, respectively) than HF patients with (P < 0.0001) and without (P < 0.0001) DM. In HF patients, an inverse correlation between early or late H/M ratio and hemoglobin A1c (HbA1c) (Pearson = −0.473, P = 0.001; Pearson = −0.382, P = 0.001, respectively) was observed. In DM, in multivariate analysis, HbA1c and ejection fraction remained significant predictors of early H/M; HbA1c remained the only significant predictor of late H/M. No correlation between early or late H/M and HbA1c was found in non-DM patients. CONCLUSIONS Diabetic patients with HF show lower cardiac sympathetic activity than HF patients not having DM or than DM patients with a similar degree of autonomic dysfunction not having HF. HbA1c correlated with the degree of reduction in cardiac sympathetic activity.

Tissue Factor Binding of Activated Factor VII Triggers Smooth Muscle Cell Proliferation via Extracellular Signal–Regulated Kinase Activation

Background—Tissue factor (TF) is the main initiator of coagulation in vivo. Recently, however, a role for TF as a cell receptor involved in signal transduction has been suggested. The aim of the present study was to assess whether activated factor VII (FVIIa) binding to TF could induce smooth muscle cell (SMC) proliferation and to clarify the possible intracellular mechanism(s) responsible for this proliferation. Methods and Results—Cell proliferation was induced by FVIIa in a dose-dependent manner, as assessed by [3H]thymidine incorporation and direct cell counting, whereas no response was observed with active site–inhibited FVIIa (FVIIai), which is identical to FVIIa but is devoid of enzymatic activity. Similarly, no proliferation was observed when binding of FVIIa to TF was prevented by the monoclonal anti-TF antibody AP-1. Activation of the p44/42 mitogen-activated protein (MAP) kinase (extracellular signal–regulated kinases 1 and 2 [ERK 1/2]) pathway on binding of FVIIa to TF was demonstrated by transient ERK phosphorylation in Western blots and by suppression of proliferation with the specific MEK (MAP kinase/ERK kinase) inhibitor UO126. ERK phosphorylation was not observed with FVIIai or when cells were pretreated with AP-1. Conclusions—These data indicate a specific effect by which binding of FVIIa to TF on the surface of SMCs induces proliferation via a coagulation-independent mechanism and possibly indicate a new link between coagulation, inflammation, and atherosclerosis.

Adhesion molecules and cardiovascular risk in peripheral arterial disease Soluble vascular cell adhesion molecule-1 improves risk stratification

Although intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) play a relevant role in atherosclerosis, little is known about the prognostic impact of their soluble forms (s) in patients with peripheral arterial disease (PAD). The aim of this prospective study was to verify whether plasma levels of sICAM-1 and sVCAM-1 predict cardiovascular risk in PAD, and improve the prognostic value of the ankle/brachial index (ABI) alone. Accordingly, plasma levels of sICAM-1 and sVCAM-1, and the ABI were measured in 75 PAD patients who were monitored for a mean of 24+/-13 months. Twenty-two (29.3%) patients had a cardiovascular event (15 coronary, 3 cerebrovascular and 4 peripheral events). Plasma levels of sVCAM-1 were 618+/-258 ng/mL in patients with and 496+/-164 ng/mL in those without an event (p=0.016). The corresponding sICAM-1 values were 344+/-239 ng/mL and 275+/-99 ng/mL (p=0.079). The cardiovascular event rate was higher in patients with sVCAM-1 levels above the median than in those with sVCAM-1 below the median (p=0.0027 by log rank test). Independent predictors of events were sVCAM-1 levels above the median (p=0.005) and an ABI below the median (p=0.001). Amongst patients with ABI below the median, the occurrence of sVCAM-1 above the median was associated with a 3.4-fold increase in risk (95% CI 1.308 to 9.573, p=0.013). In conclusion, increased plasma levels of sVCAM-1 have a negative prognostic impact in PAD and improve the predictive value of ABI, which is currently the most powerful risk indicator in these patients.

In concomitant coronary and peripheral arterial disease, inflammation of the affected limbs predicts coronary artery endothelial dysfunction

BACKGROUND In coronary artery disease (CAD), concomitant peripheral arterial disease (PAD) entails more severe coronary atherosclerosis. We investigated whether the inflammatory status of affected limbs impairs coronary artery endothelial function (CAEF). METHODS We measured the neutrophil myeloperoxidase content (NMPOxC) and plasma levels of interleukin-6 and C-reactive protein in the aorta, femoral vein, and coronary sinus of 22 CAD+PAD and 18 CAD-alone patients. CAEF was assessed by the cold pressure test. Human coronary artery endothelial cells (HCAECs) were incubated with serum from the femoral vein and aorta of CAD+PAD patients to determine whether blood leaving the affected limb activates HCAECs. RESULTS In CAD+PAD patients, NMPOxC was higher across the femoral circulation than across the coronary circulation (p<0.01); it was also higher than across healthy femoral circulation of CAD patients (p<0.01). These findings apply also to interleukin-6, but not to C-reactive protein. The transfemoral gradient of NMPOxC and interleukin-6 significantly correlated with CAEF. The NMPOxC/CAEF relationship was much greater after exercise (R=0.79, p<0.001), which increased neutrophil activation across the affected circulation. The post-exercise association remained significant after adjustment for potential confounders (p<0.01). Serum from the affected limb of CAD+PAD patients induced, in vitro, a significant release of MCP-1 from HCAECs versus serum from the aorta of the same patients (630 [550-740] vs. 547 [490-620]; p<0.05). CONCLUSIONS In CAD+PAD, triggers from the affected circulation may activate the endothelium at distant sites. Thus, PAD, besides being a marker of cardiovascular risk, could exert a mechanistic function in CAD progression.

Effect of Propionylcarnitine on Changes in Endothelial Function and Plasma Levels of Adhesion Molecules Induced by Acute Exercise in Patients with Intermittent Claudication

In patients with intermittent claudication, treadmill exercise may cause acute deterioration of endothelial function and increase in plasma concentrations of adhesion molecules. The authors evaluated the efficacy of intravenously administered propionylcarnitine (PLC) in preventing these phenomena. Thirty-six claudicants with postexercise decrease in brachial artery flow-mediated dilation (FMD) were randomized to either placebo or PLC (600 mg as a single bolus followed by 1 mg/kg/min for 60 minutes). In the 18 patients randomized to placebo, FMD markedly decreased with exercise before (from 6.8 ±0.4% to 4.0 ±0.4%; p<0.001) and after treatment (from 6.5 ±0.4% to 4.4 ±0.5%; p<0.001). By contrast, in the PLC group, FMD significantly decreased with exercise before treatment (from 8.0 ±0.7% to 4.4 ±0.4%; p<0.001), but not after active drug administration (from 7.1 ±0.7% to 6.0 ±0.6%; p=0.067). The difference between treatments was not significant (p=0.099; ANOVA). However, in the PLC group, the authors found that the greater the exercise-induced deterioration in endothelial function before treatment, the greater the capacity of PLC to prevent a postexercise decrease in FMD (r = -0.50, p=0.034). Accordingly, they analyzed data in the 19 patients with a baseline exercise-induced decrease in FMD ≥45% (ie, the median FMD reduction in the entire group of 36 patients), and found that the exercise-induced FMD decrease was less after PLC than after placebo (p=0.046, ANOVA). In the same subgroup, the exercise-induced increase in plasma concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1) was significantly higher before than after treatment in patients randomized to PLC (23.4 ±5% vs 15.3 ±7%, p=0.007). In conclusion, in patients with intermittent claudication suffering from a greater endothelial derangement after treadmill, PLC administration provided a protective effect against deterioration of FMD and increase of sVCAM-1 induced by exercise