Dustin K. Smith, DO; Michael J. Arnold, MD; Job Larson, MD How to refine your approach Jacksonville Family Medicine Residency Program, Naval Hospital Jacksonville, FL (Dr. to peripheral arterial disease Smith); Uniformed Services University of the Health Sciences, Bethesda, MD Early recognition, management of comorbid conditions, (Dr. Arnold); Naval Hospital Naples, Italy (Dr. Larson) and appropriate treatment of peripheral arterial disease dustinksmith@yahoo. can help you improve your patient’s outcome. com The authors reported no potential conflict of interest relevant to this article. eripheral arterial disease (PAD), the progressive disor- The views expressed in this PRACTICE der that results in ischemia to distal vascular territories article are those of the authors RECOMMENDATIONS and do not necessarily reflect as a result of atherosclerosis, spans a wide range of pre- the official policy or position of ❯ Use the ankle-brachial P the Department of the Navy, sentations, from minimally symptomatic disease to limb isch- index for diagnosis in Uniformed Services University of emia secondary to acute or chronic occlusion. the Health Sciences, Department patients with history/ of Defense, or the United States The prevalence of PAD is variable, due to differing diag- government. physical exam findings suggestive of peripheral nostic criteria used in studies, but PAD appears to affect 1 in doi: 10.12788/jfp.0115 1 arterial disease (PAD). A every 22 people older than age 40. However, since PAD inci- ❯ dence increases with age, it is increasing in prevalence as the Strongly encourage smoking 1-3 cessation in patients with US population ages. PAD as doing so reduces PAD is associated with increased hospitalizations and de- 4 5-year mortality and creased quality of life. Patients with PAD have an estimated amputation rates. B 30% 5-year risk for myocardial infarction, stroke, or death from a vascular cause.3 ❯ Use structured exercise ❚ programs for patients with Screening. Although PAD is underdiagnosed and ap- 3 intermittent claudication pears to be undertreated, population-based screening for PAD prior to consideration of in asymptomatic patients is not recommended. A Cochrane re- revascularization; doing view found no studies evaluating the benefit of asymptomatic so offers similar benefit population-based screening.5 Similarly, in 2018, the USPSTF and lower risks. A performed a comprehensive review and found no studies to ❯ Recommend support routine screening and determined there was insuffi- revascularization for cient evidence to recommend it.6,7 patients who have limb ischemia or lifestyle-limiting claudication despite medical Risk factors and and exercise therapy. B associated comorbidities Strength of recommendation (SOR) PAD risk factors, like the ones detailed below, have a poten- A Good-quality patient-oriented tiating effect. The presence of 2 risk factors doubles PAD risk, evidence while 3 or more risk factors increase PAD risk by a factor B Inconsistent or limited-quality 1 patient-oriented evidence of 10. ❚ C Consensus, usual practice, Increasing age is the greatest single risk factor for opinion, disease-oriented PAD.1,2,8,9 Researchers using data from the National Health and evidence, case series Nutrition Examination Survey (NHANES) found that the prev- alence of PAD increased from 1.4% in individuals ages 40 to 1 49 years to almost 17% in those age 70 or older. 500 THE JOURNAL OF FAMILY PRACTICE | DECEMBER 2020 | VOL 69, NO 10 Patients with PAD have an estimated 30% 5-year risk for myocardial infarction, stroke, or death from a vascular cause. ❚ Demographic characteristics. Most smokers.1 Risk increases linearly with cumu- studies demonstrate a higher risk for PAD lative years of smoking.1,2,9,10 in men.1-3,10 African-American patients have ❚ Diabetes is another significant modi- more than twice the risk for PAD, compared fiable risk factor, increasing PAD risk by 2.5 with Whites, even after adjustment for the times.2 Diabetes is also associated with in- increased prevalence of associated diseases creases in functional limitation from claudi- such as hypertension and diabetes in this cation, risk for acute coronary syndrome, and population.1-3,10 progression to amputation.1 ❚ Genetics. A study performed by the ❚ Hypertension nearly doubles the risk National Heart Lung and Blood Institute for PAD, and poor control further increases suggested that genetic correlations between this risk.2,9,10 twins were more important than environ- ❚ Chronic kidney disease (CKD). Patients mental factors in the development of PAD.11 with CKD have a progressively higher preva- IMAGE: ©KOSTUDIOS ❚ Smoking. Most population studies lence of PAD with worsening renal function.1 show smoking to be the greatest modifi- There is also an association between CKD able risk factor for PAD. An analysis of the and increased morbidity, revascularization NHANES data yielded an odds ratio (OR) of failure, and increased mortality.1 4.1 for current smokers and of 1.8 for former ❚ Two additional risk factors that are MDEDGE.COM/FAMILYMEDICINE VOL 69, NO 10 | DECEMBER 2020 | THE JOURNAL OF FAMILY PRACTICE 501 less well understood are dyslipidemia and Diagnostic testing chronic inflammation. There is conflicting An ankle-brachial index (ABI) test should be data regarding the role of individual compo- performed in patients with history or physi- nents of cholesterol and their effect on PAD, cal exam findings suggestive of PAD. A resting although lipoprotein (a) has been shown to ABI is performed with the patient in the su- be an independent risk factor for both the pine position, with measurement of systolic development and progression of PAD.12 Simi- blood pressure in both arms and ankles using larly, chronic inflammation has been shown a Doppler ultrasound device. TABLE 213 out- to play a role in the initiation and progression lines ABI scoring and interpretation. of the disease, although the role of inflamma- An ABI > 1.4 is an invalid measurement, tory markers in evaluation and treatment is indicating that the arteries are too calcified unclear and assessment for these purposes is to be compressed. These highly elevated ABI not currently recommended.12,13 measurements are common in patients with diabetes and/or advanced CKD. In these pa- tients, a toe-brachial index (TBI) test should Diagnosis be performed, because the digital arteries are Clinical presentation almost always compressible.13 Lower extremity pain is the hallmark symp- Patients with symptomatic PAD who are tom of PAD, but presentation varies. The clas- under consideration for revascularization African- sic presentation is claudication, pain within may benefit from radiologic imaging of the American a defined muscle group that occurs with ex- lower extremities with duplex ultrasound, patients have ertion and is relieved by rest. Claudication is computed tomography angiography, or more than twice most common in the calf but also occurs in magnetic resonance angiography to deter- the risk for PAD, the buttock/thigh and the foot. mine the anatomic location and severity of compared with However, most patients with PAD present stenosis.13 Whites, even with pain that does not fit the definition of clau- after adjustment dication. Patients with comorbidities, physical for the increased inactivity, and neuropathy are more likely to Management of PAD prevalence present with atypical pain.14 These patients may Lifestyle interventions of associated demonstrate critical or acute limb ischemia, For patients with PAD, lifestyle modifications diseases in this characterized by pain at rest and most often are an essential—but challenging—compo- population. localized to the forefoot and toes. Patients with nent of disease management. critical limb ischemia may also present with ❚ Smoking cessation. As with other nonhealing wounds/ulcers or gangrene.15 atherosclerotic diseases, PAD progression ❚ Physical exam findings can support is strongly correlated with smoking. A tri- the diagnosis of PAD, but none are reliable al involving 204 active smokers with PAD enough to rule the diagnosis in or out. Find- showed that 5-year mortality and amputa- ings suggestive of PAD include cool skin, tion rates dropped by more than half in those presence of a bruit (iliac, femoral, or poplite- who quit smoking within a year, with num- al), and palpable pulse abnormality. Multiple bers needed to treat (NNT) of 6 for mortal- abnormal physical exam findings increase ity and 5 for amputation.19 Because of this the likelihood of PAD, while the absence of dramatic effect, American College of Cardi- a bruit or palpable pulse abnormality makes ology/American Heart Association (ACC/ PAD less likely.16 In patients with PAD, an as- AHA) guidelines encourage providers to ad- sociated wound/ulcer is most often distal in dress smoking at every visit and use cessation the foot and usually appears dry.17 programs and medication to increase quit ❚ The differential diagnosis for intermit- rates.13 tent leg pain is broad and includes neurolog- ❚ Exercise may be the most important in- ic, musculoskeletal, and venous etiologies. tervention for PAD. A 2017 Cochrane review TABLE 118 lists some common alternate diag- found that supervised, structured exercise noses for patients presenting with leg pain or programs increase pain-free and maximal claudication. walking distances by at least 20% and also im- 502 THE JOURNAL OF FAMILY PRACTICE | DECEMBER 2020 | VOL 69, NO 10 PERIPHERAL ARTERIAL DISEASE TABLE 1 Differential diagnosis for leg pain