Initial management of a patient at risk of PAD or with PAD at any stage should involve an open discussion about the patient’s diet and advice upon ways in which it could be changed. Modifying diet has the capacity to ameliorate the traditional risk factors mentioned as emerging evidence continues to highlight the inverse associations with PAD for some fats, antioxidants, folate, and vitamins found in fruits and vegetables. Clinicians have traditionally advised a low-fat diet with very limited alcohol intake, however recent evidence for adoption of the ‘Med diet’ contradicts such advice and is proving superior in its preventative benefits for atherosclerotic diseases such as PAD (Marin, et al. 2011). The Mediterranean diet is a fairly high-fat diet, rich in monounsaturated fats through the consumption of unrefined grains, vegetables, fruit and nuts, but little red or processed meats and a moderate alcohol intake. This alcohol intake is thought to be responsible for the success of the Med Diet due to the anti-oxidative polyphenols found in red wine. Light-to-moderate alcohol drinkers are shown to have a reduced risk of PAD than abstainers, although this contradicts the traditional advice that suggests avoiding alcohol to improve your diet (Huang et al, 2017).
Several epidemiological studies have shown that the effects of long term alcohol use are considerably associated with the risk of PAD, however it is now understood that the pattern of alcohol usage such as the frequency of alcohol intoxication is just as much a risk factor for PAD prognosis (Fig.4) as the volume consumed and so this should be considered when managing patients and their lifestyle (Huang et al, 2017). Figure 4. Contrast of the Incidence of Peripheral Arterial Disease between patients with and without alcohol intoxication over a period of 12 years (Huang et al, 2017). Hypertension and Anti-hypertensives Hypertension (HTN) is associated with a three-fold increased risk of PAD and affects a staggering 55% of those diagnosed. The oscillatory shear stress of high blood pressure (BP) disrupts the glycocalyx of the vessels endothelial lining to impair the wall plasticity, and as endothelial function is said to predict clinical outcome, current guidelines support the aggressive treatment of blood pressure in patients with atherosclerosis. Hypertension should be managed through a combination of exercise and antihypertensive agents that can be prescribed to lower the pressure to the recommended guideline of <140/90mmHg or 130/90mmHg in diabetic patients.
The UKPDS study shown that reducing a patient’s blood pressure by just 10mmHg is shown to confer a 16% decrease in the rate of end-stage PAD, PAD-related amputation and death (Adler, Stratton et al. 2000). The choice of antihypertensive is said to be less relevant than the actual control of BP. First line therapies usually include a low dose of a thiazide diuretic such as indapamide, in combination with an angiotensin converting enzyme inhibitor (ACEi) for maximal benefit. Ramipril and Perindopril are the most commonly prescribed ACE inhibitors and have both proven equally effective at decreasing the risk of cardiovascular events in PAD patients by approximately 22% in the HOPE and EUROPA trials respectively (Yusuf, et al. 2000)(Fox, K.
M. 2003). Obesity and exercise therapyAccording to the REACH registry, almost half of PAD patients are obese with a body mass index >30 which hampers their exercise capacity; resulting in an impaired quality of life (QOL) due to a more rapid loss of mobility. Management of obese PAD patients should involve counselling for weight reduction by reducing calorie and carbohydrate intake, complemented by a supervised exercise programme consisting of 30 minutes of submaximal exercise, 3 times per week to contribute to weight loss. It is shown that as a patient begins to lose weight, the severity and frequency of their calf symptoms diminish in a dose-response fashion, improving their QOL. In a meta-analysis, exercise training resulting in a 180% improvement in the walking time in PAD patients with IC, in addition to ameliorating many of the risk factors discussed. (Gardner and Poehlman, 1995).
ConclusionIncreased awareness of the prevalence of peripheral arterial disease and its usefulness as a surrogate for poor vascular health should be utilised through increased recognition and prompt treatment of the disease within the clinic and secondary care. Once a diagnosis is established, clinicians should be judicious in their careful management of the early stages of the disease through a comprehensive tailored program aimed at aggressive atherosclerotic risk factor modification through lifestyle changes and pharmaceutical therapies.The recent identification of other novel risk factors such as CRP, hyperhomocysteinaemia, low serum 25-hydroxyvitamin D levels, and very recently lipoprotein associated phospholipase A2 provide multidisciplinary teams involved in the treatment of PAD with great optimism for improved identification and surveillance of the disease. The future of PAD diagnosis and prognosis is brightened further by the promise of personalised treatment due to genetic and stem-cell treatments currently in development – adding to the ever-expanding armamentarium that aims to enhance the identification and treatment of PAD.