Society for Vascular Surgery practice guidelines for atherosclerotic occlusive disease of the lower extremities: Management of asymptomatic disease and claudication

Peripheral arterial disease (PAD) continues to grow in global prevalence and consumes an increasing amount of resources in the United States health care system. Overall rates of intervention for PAD have been rising steadily in recent years. Changing demographics, evolution of technologies, and an expanding database of outcomes studies are primary forces influencing clinical decision making in PAD. The management of PAD is multidisciplinary, involving primary care physicians and vascular specialists with varying expertise in diagnostic and treatment modalities. PAD represents a broad spectrum of disease from asymptomatic through severe limb ischemia. The Society for Vascular Surgery Lower Extremity Practice Guidelines committee reviewed the evidence supporting clinical care in the treatment of asymptomatic PAD and intermittent claudication (IC). The committee made specific practice recommendations using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) system. There are limited Level I data available for many of the critical questions in the field, demonstrating the urgent need for comparative effectiveness research in PAD. Emphasis is placed on risk factor modification, medical therapies, and broader use of exercise programs to improve cardiovascular health and functional performance. Screening for PAD appears of unproven benefit at present. Revascularization for IC is an appropriate therapy for selected patients with disabling symptoms, after a careful risk-benefit analysis. Treatment should be individualized based on comorbid conditions, degree of functional impairment, and anatomic factors. Invasive treatments for IC should provide predictable functional improvements with reasonable durability. A minimum threshold of a >50% likelihood of sustained efficacy for at least 2 years is suggested as a benchmark. Anatomic patency (freedom from restenosis) is considered a prerequisite for sustained efficacy of revascularization in IC. Endovascular approaches are favored for most candidates with aortoiliac disease and for selected patients with femoropopliteal disease in whom anatomic durability is expected to meet this minimum threshold. Conversely, caution is warranted in the use of interventions for IC in anatomic settings where durability is limited (extensive calcification, small-caliber arteries, diffuse infrainguinal disease, poor runoff). Surgical bypass may be a preferred strategy in good-risk patients with these disease patterns or in those with prior endovascular failures. Common femoral artery disease should be treated surgically, and saphenous vein is the preferred conduit for infrainguinal bypass grafting. Patients who undergo invasive treatments for IC should be monitored regularly in a surveillance program to record subjective improvements, assess risk factors, optimize compliance with cardioprotective medications, and monitor hemodynamic and patency status. Peripheral arterial disease (PAD) continues to grow in global prevalence and consumes an increasing amount of resources in the United States health care system. Overall rates of intervention for PAD have been rising steadily in recent years. Changing demographics, evolution of technologies, and an expanding database of outcomes studies are primary forces influencing clinical decision making in PAD. The management of PAD is multidisciplinary, involving primary care physicians and vascular specialists with varying expertise in diagnostic and treatment modalities. PAD represents a broad spectrum of disease from asymptomatic through severe limb ischemia. The Society for Vascular Surgery Lower Extremity Practice Guidelines committee reviewed the evidence supporting clinical care in the treatment of asymptomatic PAD and intermittent claudication (IC). The committee made specific practice recommendations using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) system. There are limited Level I data available for many of the critical questions in the field, demonstrating the urgent need for comparative effectiveness research in PAD. Emphasis is placed on risk factor modification, medical therapies, and broader use of exercise programs to improve cardiovascular health and functional performance. Screening for PAD appears of unproven benefit at present. Revascularization for IC is an appropriate therapy for selected patients with disabling symptoms, after a careful risk-benefit analysis. Treatment should be individualized based on comorbid conditions, degree of functional impairment, and anatomic factors. Invasive treatments for IC should provide predictable functional improvements with reasonable durability. A minimum threshold of a >50% likelihood of sustained efficacy for at least 2 years is suggested as a benchmark. Anatomic patency (freedom from restenosis) is considered a prerequisite for sustained efficacy of revascularization in IC. Endovascular approaches are favored for most candidates with aortoiliac disease and for selected patients with femoropopliteal disease in whom anatomic durability is expected to meet this minimum threshold. Conversely, caution is warranted in the use of interventions for IC in anatomic settings where durability is limited (extensive calcification, small-caliber arteries, diffuse infrainguinal disease, poor runoff). Surgical bypass may be a preferred strategy in good-risk patients with these disease patterns or in those with prior endovascular failures. Common femoral artery disease should be treated surgically, and saphenous vein is the preferred conduit for infrainguinal bypass grafting. Patients who undergo invasive treatments for IC should be monitored regularly in a surveillance program to record subjective improvements, assess risk factors, optimize compliance with cardioprotective medications, and monitor hemodynamic and patency status. The Society for Vascular Surgery (SVS) Lower Extremity Guidelines Committee began the process by developing a detailed outline of the diagnostic and management choices for peripheral arterial disease (PAD) by stage of disease. Given the broad scope of the field, the committee determined that this document should focus on the evaluation and management of asymptomatic disease and intermittent claudication (IC). Separate practice guidelines for critical limb ischemia (CLI) will be established in a future document. The committee developed sets of key questions and, with the input of a methodologist, condensed these into topics that framed systematic evidence reviews. The quantity and quality of evidence available was also an important factor in determining the rationale for the systematic review topics. De novo evidence reviews were undertaken to examine the rationale for screening in asymptomatic PAD and the comparative effectiveness of current treatments for IC. These systematic reviews are published jointly with this guideline document.1Alahdab F. Wang A.T. Elraiyah T.A. Malgor R.D. Rizvi A.Z. Lane M.A. et al.A systematic review for the screening for peripheral arterial disease in asymptomatic patients.J Vasc Surg. 2015; 61: 42S-53SAbstract Full Text Full Text PDF PubMed Scopus (2) Google Scholar, 2Malgor R.D. Alalahdab F. Elraiyah T.A. Rizvi A.Z. Lane M.A. Prokop L.J. et al.A systematic review of treatment of intermittent claudication in the lower extremities.J Vasc Surg. 2015; 61: 54S-73SAbstract Full Text Full Text PDF PubMed Scopus (2) Google Scholar The committee developed the practice guideline by assigning two or three members to create primary drafts of each section of the document, highlighting specific questions where recommendations were needed and appropriate. Each section was then reviewed and revised by the remainder of the writing group and the two co-chairs. All guideline recommendations were reviewed by the full committee and finalized via an iterative, consensus process. In considering available treatment modalities, we focused on options currently available to patients and physicians in the United States (U.S.). The Grades of Recommendation Assessment, Development and Evaluation (GRADE) framework was used for determining the strength of recommendation and the quality of evidence, as previously reported.3Gloviczki P. Comerota A.J. Dalsing M.C. Eklof B.G. Gillespie D.L. Gloviczki M.L. et al.The care of patients with varicose veins and associated chronic venous diseases: clinical practice guidelines of the Society for Vascular Surgery and the American Venous Forum.J Vasc Surg. 2011; 53: 2S-48SAbstract Full Text Full Text PDF PubMed Scopus (234) Google Scholar The quality of evidence is rated as high (A), moderate (B), or low (C). This rating is based on the risk of bias, precision, directness, consistency, and the size of the effect. The strength of recommendation is graded based on the quality of evidence, balance between benefits and harms, patients' values, preferences, and clinical context. Recommendations are graded as strong (1) or weak/conditional (2). The term “we recommend” is used with strong recommendations, and the term “we suggest” is used with conditional recommendations. The methodologist assisted the committee in incorporating the evidence into the recommendations and helped in rating the quality of evidence and the strength of recommendations. Finally, this guideline was reviewed by the SVS Documents Oversight Committee that peer reviewed the document and provided content and methodology expertise. All members of the committee provided updated disclosures on potential conflicts of interest (COI), in accordance with SVS policies.4Elliott B.M. Society for Vascular Surgery. Conflict of interest and the Society for Vascular Surgery.J Vasc Surg. 2011; 54: 3-11SAbstract Full Text Full Text PDF Scopus (1) Google Scholar The final roster of the Lower Extremity Guidelines Committee is in accordance with the current SVS COI policy, which is summarized elsewhere (http://www.vascularweb.org/about/policies/Pages/Conflict-of-Interest-Policy.aspx). COI disclosures for each of the writing group authors are listed at the end of the document in the Appendix. Although the worldwide prevalence of lower extremity PAD is uncertain,5Fowkes F.G. Rudan D. Rudan I. Aboyans V. Denenberg J.O. McDermott M.M. et al.Comparison of global estimates of prevalence and risk factors for peripheral artery disease in 2000 and 2010: a systematic review and analysis.Lancet. 2013; 382: 1329-1340Abstract Full Text Full Text PDF PubMed Scopus (148) Google Scholar an estimated 8 to 12 million Americans are affected by PAD.6Criqui M.H. Langer R.D. Fronek A. Feigelson H.S. Klauber M.R. McCann T.J. et al.Mortality over a period of 10 years in patients with peripheral arterial disease.N Engl J Med. 1992; 326: 381-386Crossref PubMed Google Scholar, 7Hirsch A.T. Hartman L. Town R.J. Virnig B.A. National health care costs of peripheral arterial disease in the Medicare population.Vasc Med. 2008; 13: 209-215Crossref PubMed Scopus (80) Google Scholar A clear association between the prevalence of PAD and increased age has been established.8Selvin E. Erlinger T.P. Prevalence of and risk factors for peripheral arterial disease in the United States: results from the National Health and Nutrition Examination Survey, 1999-2000.Circulation. 2004; 110: 738-743Crossref PubMed Scopus (887) Google Scholar, 9Norgren L. Hiatt W.R. Dormandy J.A. Nehler M.R. Harris K.A. Fowkes F.G. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II).J Vasc Surg. 2007; 45: S5-67Abstract Full Text Full Text PDF PubMed Scopus (1802) Google Scholar In an analysis of 2381 patients participating in the U.S. National Health and Nutrition Examination Survey, the prevalence of PAD was 4.3% overall, with a prevalence of 0.9% in patients aged between 40 and 49 years, 2.5% in patients aged between 50 and 59 years, 4.7% in patients aged between 60 and 69 years, and 14.5% in patients aged >69 years.8Selvin E. Erlinger T.P. Prevalence of and risk factors for peripheral arterial disease in the United States: results from the National Health and Nutrition Examination Survey, 1999-2000.Circulation. 2004; 110: 738-743Crossref PubMed Scopus (887) Google Scholar The prevalence of PAD is expected to increase in the United States and worldwide as the population ages, cigarette smoking persists, and the epidemics of diabetes mellitus, hypertension, and obesity grow.7Hirsch A.T. Hartman L. Town R.J. Virnig B.A. National health care costs of peripheral arterial disease in the Medicare population.Vasc Med. 2008; 13: 209-215Crossref PubMed Scopus (80) Google Scholar A recent meta-analysis of 34 studies that examined the prevalence and risk factors of PAD worldwide shattered some preconceived notions related to this disease.5Fowkes F.G. Rudan D. Rudan I. Aboyans V. Denenberg J.O. McDermott M.M. et al.Comparison of global estimates of prevalence and risk factors for peripheral artery disease in 2000 and 2010: a systematic review and analysis.Lancet. 2013; 382: 1329-1340Abstract Full Text Full Text PDF PubMed Scopus (148) Google Scholar With a conservative estimate of >202 million afflicted with this disease globally, this analysis showed a relative increase in PAD prevalence of 23.5% during the first decade of the new millennium. The most striking increases in prevalence were seen in low-income and middle-income countries (28.7%), although significant growth was also evident in high-income countries (13.1%). In high-income countries, PAD prevalence is equal between women and men, whereas in low-income and middle-income countries, PAD prevalence is higher in women, especially at younger ages. Increased longevity (age), smoking, and diabetes are the most strongly associated risk factors across all nations. The economic effect of this growing burden of PAD is being experienced acutely in the United States and in many other industrialized nations. In 2001, the U.S. Medicare program spent an estimated >$4.3 billion on PAD-related treatment.7Hirsch A.T. Hartman L. Town R.J. Virnig B.A. National health care costs of peripheral arterial disease in the Medicare population.Vasc Med. 2008; 13: 209-215Crossref PubMed Scopus (80) Google Scholar PAD-related treatment accounted for ∼13% of all Medicare Part A and B expenditures for patients undergoing treatment for PAD and for 2.3% of total Medicare Part A and B expenditures during that year. These Medicare costs have continued to increase markedly. Analysis of data from the Reduction of Atherothrombosis for Continued Health (REACH) Registry estimated total costs of vascular-related hospitalizations was $21 billion in the United States in 2004, with most costs associated with revascularization procedures.10Mahoney E.M. Wang K. Keo H.H. Duval S. Smolderen K.G. Cohen D.J. et al.Vascular hospitalization rates and costs in patients with peripheral artery disease in the United States.Circ Cardiovasc Qual Outcomes. 2010; 3: 642-651Crossref PubMed Scopus (58) Google Scholar Given the ongoing dramatic increases in the use of invasive treatments, these figures are likely underestimates of the current costs for PAD care in the United States. Evidence of underlying PAD may be present in the absence of symptoms. For the purpose of this document, this is referred to as asymptomatic disease. Symptomatic PAD may present as IC, or with signs or symptoms consistent with limb-threatening ischemia, often referred to as critical limb ischemia (CLI). In this guidelines document, we will only consider IC within the spectrum of symptomatic PAD. IC is defined as a reproducible discomfort in a specific muscle group that is induced by exercise and then relieved with rest. Although the calf muscles are most often affected, any leg muscle group, such as those in the thigh or buttock, may be affected. This condition is caused by arterial obstruction proximal to the affected muscle bed, thereby attenuating exercise-induced augmentation of blood flow leading to transient muscle ischemia. IC is often the first clinical symptom associated with PAD and the most common. It is also well documented that many PAD patients experience “atypical” leg symptoms that may reflect other pathophysiologic mechanisms (eg, myopathy) or the overlay of concomitant conditions, such as neuropathy, arthritis, and lumbar spine disease, that influence lower extremity function. Numerous population-based studies have attempted to ascertain the relative proportion of symptomatic patients amongst all those with PAD; taken in aggregate, these studies indicate that the ratio of symptomatic to asymptomatic PAD is on the order of 1:3.9Norgren L. Hiatt W.R. Dormandy J.A. Nehler M.R. 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Creager M.A. Halperin J.L. et al.ACC/AHA 2005 Practice Guidelines for the management of patients with peripheral arterial disease (lower extremity, renal, mesenteric, and abdominal aortic): a collaborative report from the American Association for Vascular Surgery/Society for Vascular Surgery, Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology, Society of Interventional Radiology, and the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Peripheral Arterial Disease): endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation; National Heart, Lung, and Blood Institute; Society for Vascular Nursing; TransAtlantic Inter-Society Consensus; and Vascular Disease Foundation.Circulation. 2006; 113: e463-654Crossref PubMed Google ScholarView Large Image Figure ViewerDownload Hi-res image Download (PPT) Measurement of the ankle-brachial index (ABI) is the primary method for establishing the diagnosis of PAD. An ABI of ≤0.90 has been demonstrated to have high sensitivity and specificity for the identification of PAD compared with the gold standard of invasive arteriography.9Norgren L. Hiatt W.R. Dormandy J.A. Nehler M.R. Harris K.A. Fowkes F.G. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II).J Vasc Surg. 2007; 45: S5-67Abstract Full Text Full Text PDF PubMed Scopus (1802) Google Scholar Additional tests, such as carotid intima-media thickness33Robertson C.M. Gerry F. Fowkes R. Price J.F. Carotid intima-media thickness and the prediction of vascular events.Vasc Med. 2012; 17: 239-248Crossref PubMed Scopus (19) Google Scholar, 34Lorenz M.W. Markus H.S. Bots M.L. Rosvall M. Sitzer M. Prediction of clinical cardiovascular events with carotid intima-media thickness: a systematic review and meta-analysis.Circulation. 2007; 115: 459-467Crossref PubMed Scopus (1315) Google Scholar and brachial artery flow-mediated dilation,35Vita J.A. Keaney Jr., J.F. 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The incremental value of ABI beyond standard risk scores (eg, Framingham) in predicting future death and cardiovascular events has been established by epidemiologic studies.38Aboyans V. Criqui M.H. Abraham P. Allison M.A. Creager M.A. Diehm C. et al.Measurement and interpretation of the ankle-brachial index: a scientific statement from the American Heart Association.Circulation. 2012; 126: 2890-2909Crossref PubMed Scopus (141) Google Scholar An ABI <0.9 or >1.4 portends an increased risk of major cardiovascular events. The question of whether screening for PAD by ABI would yield public health benefit has been examined by several groups and remains an area of controversy. A recent review by the U.S. Preventive Services Task Force gave ABI screening an indeterminate rating, stating that there was insufficient evidence to assess the balance of benefits and harms.39Lin J.S. Olson C.M. Johnson E.S. Whitlock E.P. 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