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Intermittent claudication: a condition with underrated risks
1Department of Vascular Surgery, St George's Hospital Medical School, London, England, United Kingdom.
Insights
Intermittent claudication (IC) diagnosis is challenging due to its subjective nature. The ankle-brachial pressure index (ABPI) is a sensitive and specific noninvasive test for detecting peripheral arterial occlusive disease (PAOD).
Area of Science:
- Vascular Medicine
- Diagnostic Imaging
- Epidemiology
Background:
- Intermittent claudication (IC) is a key symptom of peripheral arterial occlusive disease (PAOD).
- Current diagnostic methods like questionnaires (WHO/Rose, Edinburgh) have low sensitivity, underestimating IC prevalence.
- Clinical examination, including pulse palpation, offers improved sensitivity but lacks specificity compared to noninvasive tests.
Purpose of the Study:
- To evaluate the diagnostic utility of the ankle-brachial pressure index (ABPI) for peripheral arterial occlusive disease (PAOD).
- To compare the sensitivity and specificity of ABPI with traditional methods for diagnosing intermittent claudication (IC).
Main Methods:
- Review of existing literature on diagnostic methods for IC and PAOD.
- Analysis of the sensitivity and specificity of questionnaires, clinical examination (pulse palpation), and ABPI.
- Inclusion of data on the prevalence and incidence of IC and asymptomatic PAOD.
Main Results:
- A resting ankle-brachial pressure index (ABPI) of 0.9 or less is highly sensitive (up to 95%) and specific (nearly 100%) for detecting significant PAOD.
- ABPI of 0.9 or less correlates with at least 50% vessel stenosis.
- The prevalence of IC increases with age, affecting 3-6% of men aged 60+, while asymptomatic PAOD may affect up to 20% of adults.
Conclusions:
- The ankle-brachial pressure index (ABPI) is a superior noninvasive diagnostic tool for peripheral arterial occlusive disease (PAOD) compared to subjective questionnaires.
- Accurate diagnosis of PAOD, both symptomatic (IC) and asymptomatic, is crucial due to its association with cardiovascular morbidity and mortality.
- ABPI enables more reliable detection and assessment of PAOD, improving patient risk stratification.
Abstract:
Intermittent claudication (IC) is a symptom of peripheral arterial occlusive disease (PAOD); it is subjective and therefore difficult to measure reliably. Both the WHO/Rose Questionnaire and the Edinburgh Questionnaire have been used widely, but they have a low sensitivity and therefore underestimate the true prevalence of IC. The addition of a clinical examination does not necessarily eliminate errors found on questionnaires alone. The single most important part of the physical examination to confirm a diagnosis of IC is the palpation of the patient's peripheral pulses, which alone appears to be more sensitive, but less specific, than the questionnaires. The most useful noninvasive test is the ankle-brachial pressure index (ABPI), and it has been suggested that a resting ABPI of 0.9 is up to 95% sensitive in detecting angiogram-positive disease, and almost 100% specific in identifying apparently healthy individuals. An ABPI of 0.9 or less is believed to be associated with 50% or greater vessel stenosis. The incidence of IC varies depending on the methodology used to define it, but there is a general pattern of a gradual increase in incidence up to the age of at least 70 years. For a chronic disease, the prevalence is a more relevant indicator of how common it is. The prevalence of IC is 3% to 6% in men aged 60 years and increases with age. The prevalence of asymptomatic PAOD may be as high as 20% in the adult population, using noninvasive testing. This is important because, as will be seen in later articles, PAOD, whether symptomatic or asymptomatic, is a serious risk factor for cardiovascular morbidity and mortality.