Intermittent claudication: magnitude of the problem, patient evaluation, and therapeutic strategies

Intermittent claudication (IC), the symptom of exercise-induced muscle ischemia of peripheral arterial disease (PAD), afflicts and limits the activities of a significant number of patients. Incidence and prevalence of IC depends on the population studied and the diagnostic instruments used. In large studies, prevalence has ranged from 3% to 10%, with a sharp increase in those aged > or =70 years. Over the next 20 years, the total number of patients affected is expected to increase significantly due to anticipated demographic changes. Analysis of the natural history of IC demonstrates that the risk of cardiovascular morbidity and mortality far exceeds that of severe limb ischemia or limb loss. In fact, only 2% to 4% of all patients with IC will require a major amputation in their lifetime. However, life expectancy is approximately 10 years less than that of an age-matched cohort. By now, PAD is well recognized as a marker of systemic atherosclerosis. The cornerstone of patient evaluation is a history and physical examination, including a detailed atherosclerotic risk-factor assessment. In the differential diagnosis of IC, clinicians should consider etiologies such as arthritis, spinal stenosis, radiculopathy, venous claudication, or inflammatory processes. In >80% of all patients, it is possible to locate the responsible arterial segment by combining the location and severity of pain with a pulse examination. Noninvasive diagnostic studies help determine the level of disease, may unmask a hemodynamically significant stenosis, and are useful in follow-up. Arteriography is reserved for patients in whom the decision for revascularization has been made. Knowing the anatomic detail of a lesion allows the clinician to determine whether and what type of intervention is feasible. Standard therapy for all patients should be directed at both peripheral and systemic atherosclerosis, beginning with risk-factor modification in the form of smoking cessation, optimal diabetes control, and lipid normalization. The benefits of supervised exercise rehabilitation include significantly increased walking distance and enhanced quality of life. Platelet inhibition has been shown to reduce the risk of ischemic stroke, myocardial infarction, and vascular death and should be prescribed for all but those in whom it is medically contraindicated. Symptom-specific pharmacotherapy with a broad range of medications has yielded disappointing results in the past. However, recent studies have demonstrated that patients receiving the novel agent cilostazol experienced increases in walking distance and improvements in quality of life.