Randomised Controlled Trial of Percutaneous Transluminal Angioplasty (PTA) Versus a Supervised Exercise Programme (SEP) in the Management of Intermittent Claudication (IC) Due to Femoro-popliteal Disease

Intermittent claudication (IC) is a common problem in the UK's elderly population with a prevalence of 5 -10%. Intermittent claudication infers significant quality of life limitations, however, it is a disease which generally runs a benign course with >80% of patients remaining stable. Yet the annual mortality rate in claudicants approaches 5%, three times that of age and sex matched population, due to the high prevalence of co-morbidity. IC is under-recognised as a risk factor for coronary and cerebrovascular events. Sixty percent of claudicants die from coronary heart disease and 10% of them die from stroke. Treating the patient with claudication, therefore, is likely to pay high dividends in terms of reducing deaths from myocardial infarction and stroke. The most appropriate management of IC, therefore remains a topic for debate but potentially beneficial therapies include: supervised exercise programmes (SEP); & percutaneous transluminal angioplasty (PTA).

A recent Cochrane review of PTA versus non-surgical management for intermittent claudication highlighted only two appropriate studies. More recently the results of a randomized control trial from Sweden have been published. This emphasizes the dearth of reliable scientific data in this area. It is believed that aorta-iliac atherosclerosis is often a solitary disease as opposed to femoro-popliteal disease which is often a manifestation of more generalized atherosclerosis. Further, the 5-year PTA patency rates for aorta-iliac disease are much better than those for femoro-popliteal PTA. Therefore, PTA is a well-established treatment modality for aorta-iliac disease but its role in femoro-popliteal disease is debatable11. This trial aims to prove the most effective treatment modality for claudication due to femoro-popliteal disease.

The two treatment modalities in question work by different mechanisms. PTA increases the blood flow to the limb. Whereas, exercise works by a combination of factors including optimized structural and metabolic performance of skeletal muscle, improvement in rheological parameters, development of collaterals, improved walking technique and marked psychological benefit. Still the efficacy of any treatment modality in claudication is judged by improvements in the standard measures of lower limb ischaemia as suggested by the International Society of Cardiovascular Surgery (ISCVS). These are essentially segmental pressure measurements and walking distances.

The primary aim of any treatment for patients with peripheral vascular disease is to improve the quality of life (QoL) rather than prolong survival. Several studies have shown that the traditional measures of lower limb ischaemia bear little correlation to the patient's QoL and these therefore need to be assessed independently. Further, generic QoL measures on their own are not sensitive enough to detect minor changes in QoL and so disease-specific measures need to be included in the outcomes.

Evidence is accumulating that each episode of exercise to the onset of claudication pain followed by rest may be considered as a low-grade ischaemia-reperfusion injury (IRI). Repeated episodes of IRI may have a cumulative effect leading to vascular endothelial damage and progression of atherosclerosis. This may explain the excess cardiovascular mortality seen in these patients16. Most experimental work measuring the biochemical markers of IRI is done following an episode of acute exercise. Few studies have shown the effect of an exercise -training programme on the biochemical markers of IRI. We intend to investigate this as a secondary component to the trial.