Background— An ankle-brachial index (ABI; ratio of ankle and brachial systolic blood pressure) 1.5 were excluded. We compared patients with ABI <0.9 according to the current definition ( with PAD , n=204 [25.0%]), those with ABI ≥0.9 according to the modified definition ( without PAD , n=524 [64.2%]), and those with ABI <0.9 according to the modified definition and ≥0.9 according to the current definition ( suspected PAD , n=88 [10.8%]). Follow-up data (median 6.6 years) were available for 812 patients (99.5%); 157 patients (19.3%) experienced cardiovascular events (cardiovascular death, myocardial infarction, or stroke). Patients without PAD had the lowest cardiovascular event rate, whereas event rates were comparable for patients with PAD and those with suspected PAD (14.8% versus 28.4% versus 25.0%, respectively). In a fully adjusted Cox regression analysis that included patients without PAD as the reference group, the hazard ratio (95% CI) was 1.56 (0.97 to 2.53) for patients with suspected PAD and 1.67 (1.16 to 2.40) for patients with PAD. Conclusions— When the higher ankle pressure is used for ABI calculation, a group of patients at high risk for cardiovascular events is overlooked. With a simple modification of ABI (use of the lower instead of the higher ankle pressure), more patients at risk could be identified.
Reactive oxygen and nitrogen species (ROS and RNS, e.g. H2O2, nitric oxide) confer redox regulation of essential cellular signaling pathways such as cell differentiation, proliferation, migration and apoptosis. At higher concentrations, ROS and RNS lead to oxidative stress and oxidative damage of biomolecules (e.g. via formation of peroxynitrite, fenton chemistry). Peripheral artery disease (PAD) is characterized by severe ischemic conditions in the periphery leading to intermittent claudication and critical limb ischemia (end stage). It is well known that redox biology and oxidative stress play an important role in this setting. We here discuss the major pathways of oxidative stress and redox signaling underlying the disease progression with special emphasis on the contribution of inflammatory processes. We also highlight therapeutic strategies comprising pharmacological (e.g. statins, angiotensin-converting enzyme inhibitors, phosphodiesterase inhibition) and non-pharmacological (e.g. exercise) interventions. Both of these strategies induce potent indirect antioxidant and anti-inflammatory mechanisms that may contribute to an improvement of PAD associated complications and disease progression by removing excess formation of ROS and RNS (e.g. by ameliorating primary complications such as hyperlipidemia and hypertension) as well as the normalization of the inflammatory phenotype suppressing the progression of atherosclerosis.
1 March 2007 in The American Journal of Cardiology
Elevated blood glucose, obesity, high blood pressure, elevated triglycerides and low high density lipoprotein (HDL) cholesterol are well accepted risk factors in the development of coronary artery disease. Clustering of at least three of these factors in an individual is defined as metabolic syndrome (MetS). Obesity is a central pathological mechanism in the disease and it is expected that the incidence of this condition will increase dramatically within the next years. The visceral adipose tissue is not only an energy depot but also an endocrine organ which produces a large number of bioactive molecules, the so called adipokines. In the setting of obesity, the over-production of proinflammatory and pro-thrombotic adipokines is associated with insulin resistance. This mechanism represents the pathophysiological basis for the development of MetS. Inflammation has a central role in the pathogenesis of MetS and in mediating its impact on the development of cardiovascular disease. Knowledge of these mechanisms has relevance in the context of preventive and therapeutic strategies.
The use of β-receptor blockers in peripheral arterial disease is controversial for their impact on vasomotor tone. The β-blocker nebivolol possesses vasodilating, endothelium-dependent, NO-releasing properties that might be beneficial in peripheral arterial disease. The aim of the study was to evaluate the effects and tolerability of nebivolol in comparison with metoprolol in these patients. A total of 128 patients with intermittent claudication and essential hypertension were included and double-blind randomized to receive 5 mg of nebivolol (N=65) or 95 mg of metoprolol (N=63) once daily. End points were changes in ankle-brachial index, initial and absolute claudication distance, endothelial function assessed by flow-mediated dilatation of the brachial artery, blood pressure, and quality of life using the claudication scale questionnaire. End point analysis was possible in 109 patients (85.2%). After the 48-week treatment period, ankle-brachial index and absolute claudication distance improved significantly in both patient groups (P<0.05 for both), with no difference across treatments. A significant increase of initial claudication distance was found in the nebivolol group. Adjusted mean change of initial claudication distance was 33.9% after nebivolol (P=0.003) and 16.6% after metoprolol (P=0.12) treatment. Quality of life was not influenced by either treatment, and there was no relevant change in flow-mediated dilatation in patients treated with nebivolol or metoprolol (P=0.16). Both drugs were equally effective in lowering blood pressure. In conclusion, β-blocker therapy was well tolerated in patients with intermittent claudication and arterial hypertension during a treatment period of ≈1 year. In the direct comparison, there was no significant difference between nebivolol and metoprolol.
All guidelines worldwide strongly recommend exercise as a pillar of the management of patients affected by lower extremity peripheral artery disease (PAD). Exercise therapy in this setting presents different modalities, and a structured programme provides optimal results. This clinical consensus paper is intended for clinicians to promote and assist for the set-up of comprehensive exercise programmes to best advice in patients with symptomatic chronic PAD. Different exercise training protocols specific for patients with PAD are presented. Data on patient assessment and outcome measures are narratively described based on the current best evidence. The document ends by highlighting disparities in access to supervised exercise programmes across Europe and the series of gaps for evidence requiring further research.