CHAPTER 96: DIAGNOSIS AND MANAGEMENT OF DISEASES OF THE PERIPHERAL ARTERIES

INTRODUCTION

Peripheral vascular diseases are a diverse collection of disorders that affect all organ systems. Peripheral artery disease (PAD) is the vascular disease most commonly encountered by the cardiologist; however, disease of the lymphatics and veins is equally common globally. For the cardiologist or internist with an interest in vascular disorders, a systematic and comprehensive approach is required. This chapter will cover commonly encountered areas of vascular disease, specifically the diagnosis and management of PAD. Accompanying chapters on lymphedema, venous disease, and aortic and cerebrovascular disease will address these topics in more detail.

PERIPHERAL ARTERY DISEASE

PAD caused by atherosclerosis is the most common cause of lowerextremity ischemic syndromes in Western societies.¹ PAD is a major cause of lifestyle changes, poor quality of life, loss of work, disability, and significant morbidity and mortality in the United States.^2,3 Symptoms of PAD are variable and, unfortunately, frequently lead to incorrect diagnoses.⁴ Risk factors for PAD are the same as those for coronary artery disease (CAD), with tobacco and diabetes having an even greater effect (Table 96–1).^5,6 Tobacco use, current and past, is associated with a two- to fourfold increase in relative risk for PAD.^7,8 Diabetes mellitus has a similar increase in relative risk.⁷ Other modifiable risk factors include hyperhomocysteinemia, hyperlipidemia, and hypertension.⁹ Even when asymptomatic, PAD has been shown to be a strong predictor of cardiovascular disease, nonfatal cardiovascular events (eg, myocardial infarction and stroke), and lower-extremity ulcerations and amputations.⁵ PAD has significant impact on mortality; individuals with PAD have a two- to sixfold higher relative risk of death over a 10-year period of time versus the general population.^10,11,12

Prevalence

PAD affects a large and increasing number of individuals worldwide.¹ Exact numbers for prevalence and incidence are confounded by varying methods for assessment and criteria for diagnosis.¹³ Expert and consensus statements estimate that 8 to 12 million people in the United States and 200 million people worldwide are affected by PAD.^14,15,16 It is estimated that 10 million people have symptomatic PAD and another 20 to 30 million have asymptomatic disease. Based on published US statistics, each year 413,000 patients with PAD are hospitalized, 88,000 lower-extremity angiograms are performed, and 30,000 patients undergo embolectomy or thrombectomy.¹⁷ Ten percent of individuals over 60 years of age have PAD, and the prevalence continues to increase with age.^5,18 It is estimated that nearly two-thirds of those affected by PAD ...