The management of patients with intermittent claudication has focused on improving symptoms caused by restricted blood flow through a limb. However, the goals of managing the condition have recently been broadened to include prevention of coronary and cerebrovascular events.
Intermittent claudication is underrecognised as a risk factor for coronary and cerebrovascular events. Sixty per cent of people with claudication die from coronary heart disease, and 10% of them die from stroke.1 Treating the person with claudication, therefore, is likely to pay high dividends in terms of reducing deaths from myocardial infarction and stroke. Morbidity and mortality in these patients can be improved by various strategies.
Exercise is widely held to be beneficial to patients with intermittent claudication, but it has been applied with little enthusiasm. In experimental models, however, exercising ischaemic muscle improved muscle performance within a short period of time. A meta-analysis of 21 studies of the effects of exercise on patients with intermittent claudication suggested that the average improvement in the distance that patients could walk was 122%.2 Programmes in which patients exercised for 30 minutes at least three times a week for six months had the greatest benefit.
Theoretical concerns about the potentially adverse effects of exercise in people with claudication seem unfounded. Although there is evidence that people with claudication develop an inflammatory-type response after walking, regular exercise attenuates this phenomenon and improves the distance they are able to walk.3 It can be difficult to get patients to continue with exercise regimens, but the main role of programmes offering supervised exercise is to maintain and reinforce the patient's enthusiasm. Supervised exercise classes are a promising component of healthcare programmes. Exercise programmes vary but involve combinations of walking up stairs, climbing, cycling, and dynamic and static leg exercises.
Smoking is one of the most important risk factors associated with intermittent claudication. In the two largest studies of the efficacy of quitting smoking in peripheral vascular disease, only 11% of 354 patients and 27% of 415 patients followed advice to stop smoking.4,5 Within the first three years after stopping smoking there was no reduction in the rate of limb threatening complications from peripheral vascular disease. However, after seven years critical limb ischaemia (pain at rest) had developed in 16% of the smokers but in none of the patients who had quit smoking. After 10 years, 53% of those who continued to smoke had had a myocardial infarction, and 54% had died. In contrast, among those who had stopped smoking, only 11% had had a myocardial infarction, and 18% had died. Nicotine replacement therapy combined with counselling is both safe and effective in helping many patients to stop smoking and should be advocated more widely.6
The benefits of treatment
The benefits of antiplatelet treatment have long been recognised in significantly reducing the risk of non-fatal vascular events or deaths in patients with myocardial infarction or stroke. More recently, the use of antiplatelet treatment in patients who have evidence of peripheral vascular disease, irrespective of the presence of comorbid cardiovascular disease, is gaining support.7,8 However, despite the fact that antiplatelet treatment significantly reduces the risk of myocardial infarction and stroke in high risk patients,9–11 a large proportion of patients with intermittent claudication are not being treated (unpublished data).
The Edinburgh artery study showed that platelet activation was 30% higher in patients with peripheral vascular disease.12 This was true even in asymptomatic patients. Antiplatelet treatment has proved to be extremely useful in managing clinical manifestations of atherosclerosis and preventing further thrombotic events. The spectrum of antiplatelet drugs available for clinical use is expanding.
Although there is no direct evidence that drugs that lower concentrations of lipids are beneficial in patients with peripheral vascular disease, they have been shown to reduce the risk of cardiovascular events in patients with established ischaemic heart disease and in patients at high risk of vascular disease. Since peripheral vascular disease is a strong risk factor for myocardial infarction and stroke, it might be expected that patients would benefit from treatment with lipid lowering agents to reduce their risk of stroke or myocardial infarction.13
While the advice to “stop smoking and keep walking” remains a key element in managing patients with claudication, it is important to recognise that claudication is usually a marker of more generalised atherosclerotic disease which will have far reaching consequences for the patient. It is increasingly being recognised that it is necessary to look more broadly at a patient's overall vascular risk and act accordingly. As such, the aims in managing this group of patients should be to get them to stop smoking, keep walking, and take antiplatelet treatment, and to assess their cholesterol concentrations and take action if they are at risk.
Acknowledgments
On behalf of the PVD working party. Members of the working party are: Janet Powell, Charing Cross Hospital; Simon Ashley, Derriford Hospital, Plymouth; Peter Bell, Leicester Royal Infirmary; Ray Cuschieri, Doncaster Royal Infirmary; John Dormandy, St George's Hospital, London; Gerry Fowkes, Wolfson Unit for Prevention of Peripheral Vascular Diseases, University of Edinburgh; Gordon Lowe, Glasgow Royal Infirmary; and Cliff Shearman, Southampton General Hospital.
Footnotes
The working party's meetings were funded by Bristol-Myers Squibb and Sanofi, which market an antiplatelet drug. AD has received funding from Sanofi for research.
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