Guidance

Recommendations for research

Recommendations for research

In 2012 the guideline committee has made the following recommendations for research. The committee's full set of research recommendations is detailed in the full guideline.

As part of the 2018 update, the standing committee made new research recommendations on the effectiveness and reliability of tools for diagnosing peripheral arterial disease in people with diabetes. Details can be found in the evidence review.

1 Effectiveness of tools for diagnosing peripheral arterial disease in people with diabetes

What is the most clinically and cost-effective tool for diagnosing peripheral arterial disease in people with diabetes?

Why this is important

People with diabetes are at higher risk of cardiovascular events and foot problems such as diabetic neuropathy (nerve damage or degeneration), foot ulcer and limb loss. So it is important to have an effective test for diagnosing peripheral arterial disease in this group. At present there are only studies of very low quality (retrospective and prospective cross‑sectional studies) containing small sample sizes. Diagnostic accuracy studies are needed to address this issue, ideally containing cost–utility analysis, comparing diagnostic tools with imaging. In order to explore the importance of early diagnosis, different clinical settings where diagnostic tests are performed should be explored. [2018]

2 Effectiveness of tools for establishing the severity of peripheral arterial disease in people with diabetes

What is the most clinically and cost-effective tool for establishing the severity of peripheral arterial disease and the impact on mortality, morbidity and limb amputation in people with diabetes?

Why this is important

Limited evidence suggests that doppler ankle brachial pressure index, toe brachial index and oscillometric ankle brachial index accurately diagnose severity of peripheral arterial disease. However, further research is needed using a robust diagnostic study design (such as a randomised controlled trial) to explore the clinical and cost effectiveness of tools in establishing the severity of disease and outcomes in people with diabetes. Studies should also explore the use of tools in different populations, such as those with neuropathy, and in different settings, for example, nursing homes, where access to services and diagnostic equipment may differ. [2018]

3 Inter- and intra-rater reliability of assessment tools in the diagnosis of peripheral arterial disease in people with diabetes

What is the inter- and intra-rater reliability of assessment tools in the diagnosis of peripheral arterial disease in people with diabetes?

Why this is important

Identifying peripheral arterial disease can be a challenge because diagnostic tests are conducted in a number of different settings by healthcare professionals with varying experience of using assessment tools. Data on inter- and intra‑rater reliability of point‑of‑care assessment tools are needed to inform future recommendations for practice. The study should compare diagnostic tests with gold standard imaging. Different clinical and community settings, such as UK primary care setting, should also be taken into account. [2018]

4 Angioplasty versus bypass surgery for treating people with critical limb ischaemia caused by disease of the infra-geniculate arteries

What is the clinical and cost effectiveness of a 'bypass surgery first' strategy compared with an 'angioplasty first' strategy for treating people with critical limb ischaemia caused by disease of the infra‑geniculate (below the knee) arteries?

Why this is important

Many people with critical limb ischaemia, especially those with diabetic vascular disease, also have disease of the infra‑geniculate (below the knee) arteries in the calf. For many years, the standard of care has been bypass surgery. Although such surgery may be associated with significant morbidity, the resulting long‑term amputation‑free survival rates are generally good. In recent years there has been a trend towards treating infra‑geniculate disease with angioplasty, on the grounds that it is associated with less morbidity than surgery. However, this change in practice is not evidence‑based, and serious concerns remain about the durability of angioplasty in this anatomical area. A multicentre, randomised controlled trial with a full health economic analysis is required to address this. The primary endpoint should be amputation‑free survival, with secondary endpoints including overall survival, health‑related quality of life, healing of tissue loss, and relief of ischaemic pain. [2012]

5 Supervised exercise programmes for treating people with intermittent claudication

What is the clinical and cost effectiveness of supervised exercise programmes compared with unsupervised exercise for treating people with intermittent claudication, taking into account the effects on long‑term outcomes and continuing levels of exercise?

Why this is important

Research has shown that taking part in exercise and physical activity can lead to improvements in symptoms in the short term for people with intermittent claudication. However, the benefits of exercise are quickly lost if it is not frequent and regular. Supervised exercise programmes have been shown to produce superior results when compared with advice to exercise (unsupervised) in the short term, but they are more expensive, and there is a lack of robust evidence on long‑term effectiveness. A community‑based randomised controlled trial is required to compare the long‑term clinical and cost effectiveness of a supervised exercise programme and unsupervised exercise. The trial should enrol people with peripheral arterial disease‑related claudication, but exclude those with previous endovascular or surgical interventions. The primary outcome measure should be maximal walking distance, with secondary outcome measures including quality of life, function, levels of uptake of exercise programmes and long‑term engagement in physical activity. [2012]

6 Patient attitudes and beliefs about peripheral arterial disease

What is the effect of people's attitudes and beliefs about their peripheral arterial disease on the management and outcome of their condition?

Why this is important

The evidence reviewed suggested that, among people with peripheral arterial disease, there is a lack of understanding of the causes of the disease, a lack of belief that lifestyle interventions will have a positive impact on disease outcomes, and unrealistic expectations of the outcome of surgical interventions. Much of the research has been conducted on the subpopulation of people with peripheral arterial disease who have been referred for surgical intervention, but little evidence is available for the majority of people diagnosed with peripheral arterial disease in a primary care setting. Research is needed to further investigate attitudes and beliefs in relation to peripheral arterial disease, interventions that might influence these and how these may have an impact on behavioural changes in relation to risk factors for peripheral arterial disease, attitudes to intervention and clinical outcomes. [2012]

7 Primary versus secondary stenting for treating people with critical limb ischaemia caused by disease of the infra-geniculate arteries

What is the clinical and cost effectiveness of selective stent placement compared with angioplasty plus primary stent placement for treating people with critical limb ischaemia caused by disease of the infra‑geniculate arteries?

Why this is important

Studies comparing angioplasty plus selective stent placement with primary stent placement have been limited to the aorto‑iliac and femoro‑popliteal segment. There is also a significant group of people with critical ischaemia caused by disease of the infra‑geniculate vessels in which there is a potential for endovascular treatment. Infra‑geniculate disease is more complex to treat by endovascular means, and the risks and benefits of different treatment options may differ from those for the more proximal vessels. A multicentre, randomised controlled trial with a full health economic analysis is required to address the optimum policy as regards the choice of method for angioplasty and stent placement for the infra‑geniculate arteries. The primary endpoint should be amputation‑free survival, with secondary endpoints including overall survival, re‑intervention rates, health‑related quality of life, healing of tissue loss, and relief of ischaemic pain. [2012]

8 Chemical sympathectomy for managing critical limb ischaemic pain

What is the clinical and cost effectiveness of chemical sympathectomy in comparison with other methods of pain control for managing critical limb ischaemic pain?

Why this is important

Approximately 1 in 5 people with critical limb ischaemia cannot be offered procedures to improve the blood supply to their leg because of either the pattern of their disease or other comorbidities. In this group the therapeutic options are pain control or primary amputation. Chemical lumbar sympathectomy, which involves the destruction of the lumbar sympathetic chain (usually the L2 and L3 ganglia), has been suggested to reduce pain and improve wound healing, and may prevent amputation in some patients. Initially achieved surgically, it is now most commonly performed using chemical agents such as phenol to destroy the lumbar sympathetic chain. Despite having been used for over 60 years, the role of chemical lumbar sympathectomy remains unclear. Improvement in skin blood flow and modification of pain perception control have been demonstrated, and this has prompted the use of chemical lumbar sympathectomy for treating a range of conditions such as regional pain syndrome, vasospastic conditions and critical limb ischaemia. However, in critical limb ischaemia the use of chemical lumbar sympathectomy varies widely between units in England, the mode of action and indications are unclear, and there is currently no randomised controlled trial evidence demonstrating its clinical value. Therefore a randomised control trial comparing chemical lumbar sympathectomy with other methods of pain relief is recommended. [2012]