Diagnosis
2.2. History and Physical Examination to Assess for PAD
- In patients at increased risk of PAD (Table 5), a comprehensive medical history and review of symptoms to assess for exertional leg symptoms, lower extremity rest pain, and lower extremity wounds or other ischemic skin changes should be performed.
( 1, B-NR )
- In patients at increased risk of PAD (Table 5), a comprehensive vascular examination and inspection of the legs and feet should be performed regularly (Table 6).
( 1, B-NR )
3.1. Resting ABI and Additional Physiological Testing
Resting ABI
- In patients with history or physical examination findings suggestive of PAD (Table 6), the resting ABI, with or without ankle pulse volume recordings (PVR) and/or Doppler waveforms, is recommended to establish the diagnosis.
( 1, B-NR )
- The resting ABI should be reported as abnormal (ABI, ≤0.90), borderline (ABI, 0.91–0.99), normal (ABI, 1.00–1.40), or noncompressible (ABI, >1.40).
( 1, B-NR )
- In patients at increased risk of PAD (Table 5), screening for PAD with the resting ABI, with or without ankle PVR and/ or Doppler waveforms, is reasonable.
( 2a, B-NR )
- In patients not at increased risk of PAD (Table 5) and without history or physical examination findings suggestive of PAD (Table 6), screening for PAD with the ABI is not recommended.
( 3 - No Benefit, B-NR )
Exercise ABI and Additional Physiological Testing
- In patients with suspected PAD, toe pressure/toe-brachial index (TBI) with waveforms should be performed when the resting ABI is >1.40 (noncompressible).
( 1, B-NR )
- Patients with suspected chronic symptomatic PAD (ie, exertional nonjoint-related leg symptoms) and normal or borderline resting ABI (>0.90 and ≤1.40, respectively) should undergo exercise treadmill ABI testing to evaluate for PAD.
( 1, B-NR )
- In patients with PAD and an abnormal resting ABI (≤0.90), the exercise treadmill ABI test can be useful to objectively assess, the functional status and walking performance.
( 2a, B-NR )
- In patients with chronic symptomatic PAD, it is reasonable to perform segmental leg pressures with PVR and/or Doppler waveforms in addition to the resting ABI to help delineate the anatomic level of PAD.
( 2a, C-LD )
- In patients with suspected CLTI, it is reasonable to use toe pressure/TBI with waveforms, transcutaneous oxygen pressure (TcPO2), and/or or skin perfusion pressure (SPP) in addition to ABI for assessment of arterial perfusion and to establish the diagnosis of CLTI.
( 2a, B-NR )
- In patients with CLTI with nonhealing wounds or gangrene, it can be useful to use toe pressure/TBI with waveforms, TcPO2, SPP, and/or other local perfusion measures to determine the likelihood of wound healing without or after revascularization.
( 2a, B-NR )
3.2. Imaging for PAD
- In patients with functionally limiting claudication with inadequate response to GDMT (including structured exercise) for whom revascularization is being considered, duplex ultrasound, computed tomography angiography (CTA), magnetic resonance angiography (MRA), or catheter angiography of the lower extremities is useful for assessment of anatomy and severity of disease and to determine potential revascularization strategy.
( 1, B-NR )
- In patients with CLTI, duplex ultrasound, CTA, MRA, or catheter angiography is useful to determine revascularization strategy.
( 1, B-NR )
- In patients with suspected PAD (ie, potential signs and/or symptoms) with inconclusive ABI and physiological testing, noninvasive imaging with duplex ultrasound, CTA, or MRA may be considered to establish the diagnosis of PAD.
( 2b, C-EO )
- In patients with a confirmed diagnosis of PAD in whom revascularization is not being considered, CTA, MRA, or catheter angiography should not be performed solely for anatomic assessment.
( 3 - Harm, B-NR )
4. Special Considerations in PAD: Risk Amplifiers, Health Disparities, and PAD in Older Patients
4.1. Amplifiers of Cardiovascular and Limb-Related Risk in Patients With PAD
- In the evaluation of patients with PAD, clinicians should assess for and incorporate the presence of PAD-related risk amplifiers (Table 9) when developing patient-focused treatment recommendations.
( 1, C-EO )
4.2. Health Disparities in PAD
- Clinicians and health care systems should actively pursue evidence of health disparities in diagnosis, treatment, and outcomes for patients with PAD and use efforts to limit the impact of these disparities on clinical outcomes.
( 1, C-EO )
4.3. Considerations in Management of PAD in Older Patients
- In older patients (ie, ≥75 years of age) with PAD, assessment for geriatric syndromes (Table 10), such as frailty, sarcopenia, malnutrition, and mobility impairment, can be useful to identify high-risk patients, including before revascularization, and to provide safe and goal-concordant care.
( 2a, B-NR )
Treatment
5. Medical Therapy and Preventive Footcare for Patients With PAD
5.1.1. Antiplatelet and Antithrombotic Therapy for PAD
- In patients with symptomatic PAD, single antiplatelet therapy is recommended to reduce the risk of MACE.
( 1, A )
- In patients with symptomatic PAD, single antiplatelet therapy with clopidogrel alone (75 mg daily) is recommended to reduce the risk of MACE.
( 1, B-R )
- In patients with symptomatic PAD, single antiplatelet therapy with aspirin alone (range, 75–325 mg daily) is recommended to reduce the risk of MACE.
( 1, C-LD )
- In patients with symptomatic PAD, low-dose rivaroxaban (2.5 mg twice daily) combined with low-dose aspirin is effective to reduce the risk of MACE and MALE.
( 1, A )
- After endovascular or surgical revascularization for PAD, antiplatelet therapy is recommended.
( 1, B-R )
- After endovascular or surgical revascularization for PAD, low-dose rivaroxaban (2.5 mg twice daily) combined with low-dose aspirin is recommended to reduce the risk of MACE and MALE.
( 1, A )
- After endovascular revascularization for PAD, dual antiplatelet therapy with a P2Y12 antagonist and low-dose aspirin is reasonable for at least 1 to 6 months.
( 2a, C-LD )
- After endovascular or surgical revascularization in patients with PAD who require full-intensity anticoagulation for another indication and are not at high risk of bleeding, adding single antiplatelet therapy is reasonable.
( 2a, C-LD )
- In patients with asymptomatic PAD single antiplatelet therapy is reasonable to reduce the risk of MACE.
( 2a, C-EO )
- In patients with symptomatic PAD without recent revascularization, the benefit of dual antiplatelet therapy is uncertain.
( 2b, B-R )
- In patients with symptomatic PAD, the benefit of vorapaxar added to existing antiplatelet therapy is uncertain.
( 2b, B-R )
- After surgical revascularization for PAD with a prosthetic graft, dual antiplatelet therapy with a P2Y12 antagonist and low-dose aspirin may be reasonable for at least 1 month.
( 2b, B-R )
- In patients with PAD without another indication (eg, atrial fibrillation), full-intensity oral anticoagulation should not be used to reduce the risk of MACE and MALE.
( 3 - Harm, A )
5.2. Lipid-Lowering Therapy for PAD
- In patients with PAD, treatment with high-intensity statin therapy is indicated, with an aim of achieving a ≥50% reduction in low-density lipoprotein cholesterol (LDL-C) level.
( 1, A )
- In patients with PAD who are on maximally tolerated statin therapy and have an LDL-C level of ≥70 mg/dL, it is reasonable to add PCSK9 inhibitor therapy.
( 2a, B-R )
- In patients with PAD who are on maximally tolerated statin therapy and have an LDL-C level of ≥70 mg/dL, it is reasonable to add ezetimibe therapy.
( 2a, B-R )
5.3. Antihypertensive Therapy for PAD
- In patients with PAD and hypertension, antihypertensive therapy should be administered to reduce the risk of MACE.
( 1, A )
- In patients with PAD and hypertension, a systolic blood pressure (SBP) goal of <130 mm Hg and a diastolic blood pressure target of <80 mm Hg is recommended.
( 1, B-R )
- In patients with PAD and hypertension, the selective use of angiotensin-converting enzyme (ACE) inhibitors or angiotensin-receptor blockers is recommended to reduce the risk of MACE.
( 1, B-R )
5.4. Smoking Cessation for PAD
- Patients with PAD who smoke cigarettes or use any other forms of tobacco should be advised at every visit to quit or encouraged to maintain cessation.
( 1, A )
- Patients with PAD who smoke cigarettes or use any other forms of tobacco should be assisted in developing a plan for quitting that includes pharmacotherapy (ie, varenicline, bupropion, and/or nicotine replacement therapies) combined with counseling, and/or referral to a smoking cessation program.
( 1, A )
- Patients with PAD should be advised to avoid exposure to secondhand tobacco smoke in all indoor or enclosed spaces, including work, home, transportation vehicles, and public places.
( 1, B-NR )
5.5. Diabetes Management for PAD
- In patients with PAD, management of diabetes should be coordinated among members of the health care team.
( 1, C-EO )
- In patients with PAD and diabetes, glycemic control may be beneficial to improve limb outcomes.
( 2b, B-NR )
5.6. Other Medical Therapies for Cardiovascular Risk Reduction in PAD
- Patients with PAD should receive an annual influenza vaccination.
( 1, C-LD )
- Patients with PAD should receive the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination sequence, including the booster(s).
( 1, C-EO )
- In patients at high cardiovascular risk, a diet emphasizing intake of vegetables, fruits, legumes, nuts, whole grains, and fish can be beneficial for reducing the risk of developing PAD and the risk of MACE.
( 2a, B-R )
- In patients with PAD, B-complex vitamin supplementation to lower homocysteine levels is not beneficial for prevention of MACE.
( 3 - No Benefit, B-R )
- In patients with PAD, chelation therapy (eg, EDTA) is not beneficial for prevention of MACE.
( 3 - No Benefit, B-R )
- In patients with PAD, vitamin D supplementation is not beneficial for prevention of MACE.
( 3 - No Benefit, B-R )
5.7. Medications for Leg Symptoms in Chronic Symptomatic PAD
Cilostazol
- In patients with claudication, cilostazol is recommended to improve leg symptoms and increase walking distance.
( 1, A )
- In patients with PAD, cilostazol may be useful to reduce restenosis after endovascular therapy for femoropopliteal disease.
( 2b, B-R )
- In patients with PAD and congestive heart failure of any severity, cilostazol should not be administered.
( 3 - Harm, C-LD )
Pentoxifylline
- In patients with chronic symptomatic PAD, pentoxifylline is not recommended for treatment of claudication.
( 3 - No Benefit, B-R )
Chelation Therapy
- In patients with chronic symptomatic PAD, chelation therapy is not recommended for treatment of claudication.
( 3 - No Benefit, B-R )
5.8. Preventive Foot Care for PAD
- In patients with PAD, providing general preventive foot self-care education to patients and their family members and support persons is recommended.
( 1, C-LD )
- In patients with PAD, foot inspection by a clinician at every visit is recommended.
( 1, C-EO )
- In patients with PAD at high risk for ulcers and amputation (Table 12), therapeutic footwear is recommended.
( 1, C-LD )
- In patients with PAD, a comprehensive foot evaluation (Table 13) should be performed at least annually to identify risk factors for ulcers and amputation.
( 1, C-EO )
- In patients with PAD, referral to a foot care specialist, when available, is reasonable for ongoing preventive care and longitudinal surveillance.
( 2a, B-NR )
6.1. Exercise Therapy for PAD
- In patients with chronic symptomatic PAD, SET is recommended to improve walking performance, functional status, and QOL.
( 1, A )
- In patients with chronic symptomatic PAD, a structured community-based exercise program with behavioral change techniques is effective to improve walking performance, functional status, and QOL.
( 1, A )
- In patients who have undergone revascularization for chronic symptomatic PAD, SET after revascularization is effective to improve walking performance, functional status, and QOL.
( 1, A )
- In patients with functionally limiting claudication, SET or a structured community-based exercise program should be offered as an initial treatment option.
( 1, B-R )
- In patients with chronic symptomatic PAD, alternative programs of nonwalking structured exercise therapy (eg, arm ergometry, recumbent stepping) can be beneficial to improve walking performance, functional status, and QOL.
( 2a, A )
- In patients with chronic symptomatic PAD, the usefulness of structured walking exercise therapy that avoids moderate to severe ischemic symptoms is uncertain.
( 2b, B-R )
- In patients with chronic symptomatic PAD, the usefulness of unstructured exercise to improve walking performance, functional status, and QOL is uncertain.
( 2b, B-R )
7.1. Revascularization for Asymptomatic PAD
- In patients with asymptomatic PAD, it is reasonable to perform revascularization procedures (endovascular or surgical) to reconstruct diseased arteries if needed for the safety, feasibility, or effectiveness of other procedures (eg, transfemoral aortic valve replacement, mechanical circulatory support, endovascular aortic aneurysm repair).
( 2a, B-NR )
- In patients with asymptomatic PAD, revascularization procedures (endovascular or surgical) should not be performed solely to prevent progression of disease.
( 3 - Harm, B-NR )
9.1. Revascularization for Claudication
Revascularization for Claudication: Initial Decision-Making
- In patients with functionally limiting claudication who are being considered for revascularization, potential benefits with respect to QOL, walking performance, and overall functional status should be weighed against the risks and durability of intervention and possible need for repeated procedures.
( 1, B-NR )
- In patients with functionally limiting claudication and an inadequate response to GDMT (including structured exercise), revascularization is a reasonable treatment option to improve walking function and QOL.
( 2a, B-R )
- In patients with claudication who have had an adequate clinical response to GDMT (including structured exercise), revascularization is not recommended.
( 3 - No Benefit, C-EO )
Revascularization for Claudication: Aortoiliac Disease and Femoropopliteal Disease (Excluding Common Femoral Artery Disease)
- In patients with functionally limiting claudication and hemodynamically significant aortoiliac or femoropopliteal disease with inadequate response to GDMT (including structured exercise), endovascular revascularization is effective to improve walking performance and QOL.
( 1, A )
- In patients with functionally limiting claudication and hemodynamically significant aortoiliac or femoropopliteal disease with inadequate response to GDMT (including structured exercise), surgical revascularization is reasonable if perioperative risk is acceptable and technical factors suggest advantages over endovascular approaches.
( 2a, B-NR )
Revascularization for Claudication: Common Femoral Artery Disease
- In patients with functionally limiting claudication and hemodynamically significant common femoral artery disease with inadequate response to GDMT (including structured exercise), surgical endarterectomy is reasonable, especially if endovascular approaches adversely affect profunda femoris artery pathways.
( 2a, B-R )
- In patients with functionally limiting claudication and hemodynamically significant common femoral artery disease with inadequate response to GDMT (including structured exercise), endovascular approaches may be considered in those at high risk for surgical revascularization and/or if anatomical factors are favorable (ie, no adverse effect on profunda femoris artery pathways).
( 2a, B-R )
Revascularization for Claudication: Infrapopliteal Disease
- In patients with functionally limiting claudication and isolated hemodynamically significant infrapopliteal disease with inadequate response to GDMT (including structured exercise), the effectiveness of endovascular revascularization is unknown.
( 2b, C-LD )
- In patients with functionally limiting claudication and isolated hemodynamically significant infrapopliteal disease with inadequate response to GDMT (including structured exercise), the effectiveness of surgical revascularization is unknown.
( 2b, C-LD )
9.2. Conduit for Surgical Revascularization for Femoropopliteal Disease
- In patients who are undergoing surgical revascularization for functionally limiting claudication and hemodynamically significant femoropopliteal disease, bypass to the popliteal artery with autogenous vein is recommended in preference to prosthetic graft material.
( 1, A )
10.1. Team-Based Care for CLTI
- In patients with CLTI, a multispecialty care team should evaluate and provide comprehensive care with goals of complete wound healing, minimizing tissue loss, and preservation of ambulatory status.
( 1, B-NR )
10.2. Revascularization for CLTI
Revascularization Goals for CLTI
- In patients with CLTI, surgical, endovascular, or hybrid revascularization techniques are recommended, when feasible, to minimize tissue loss, heal wounds, relieve pain, and preserve a functional limb.
( 1, B-R )
- In patients with CLTI, an evaluation for revascularization options by a multispecialty care team is recommended before amputation (Table 15).
( 1, C-EO )
Revascularization Strategy for CLTI
- In patients undergoing surgical revascularization for CLTI, bypass to the popliteal or infrapopliteal arteries (ie, tibial, pedal) should be constructed with autogenous vein if available.
( 1, A )
- In patients with CLTI due to infrainguinal disease, anatomy, available conduit, patient comorbidities, and patient preferences should be considered in selecting the optimal first revascularization strategy (surgical bypass or endovascular revascularization) (Table 16).
( 1, B-R )
- In patients with CLTI who are candidates for surgical bypass and endovascular revascularization, ultrasound mapping of the great saphenous vein is recommended.
( 1, B-R )
- In patients with CLTI for whom a surgical approach is selected and a suitable autogenous vein is unavailable, alternative conduits such as prosthetic or cadaveric grafts can be effective for bypass to the popliteal and tibial arteries.
( 2a, B-NR )
- In patients with CLTI and nonhealing wounds or gangrene, revascularization in a manner that achieves in-line blood flow or maximizes perfusion to the wound bed can be beneficial.
( 2a, B-NR )
- In patients with CLTI with ischemic rest pain (ie, without nonhealing wounds or gangrene) attributable to multilevel arterial disease, a revascularization strategy addressing inflow disease first is reasonable.
( 2a, C-LD )
10.3. Minimizing Tissue Loss for CLTI
10.3.1. Pressure Offloading for CLTI
- Patients with CLTI and diabetic foot ulcers should receive pressure offloading, when possible, to promote tissue growth and wound healing.
( 1, A )
- Patients with PAD and previous diabetic foot ulcers should be referred for customized footwear that accommodates, protects, and fits the shape of their feet.
( 1, B-R )
- Patients with CLTI and foot ulcers who do not have diabetes may be considered for pressure offloading to promote tissue growth and wound healing.
( 2b, C-EO )
10.3.2. Wound Care and Management of Infection for CLTI
- In patients with CLTI, prompt management of foot infection with antibiotics, debridement, and other surgical management is recommended.
( 1, B-NR )
- In patients with CLTI with nonhealing wounds, wound care should be provided to optimize the wound-healing environment after revascularization with the goal of complete wound healing.
( 1, C-LD )
- In patients with CLTI with nonhealing diabetic foot ulcers, hyperbaric oxygen therapy may be considered to assist in wound healing after revascularization.
( 2b, B-NR )
10.3.3. Approach to the “No Option” Patient With CLTI
- In patients with CLTI for whom revascularization is not an option and a lack of outflow to the foot is observed, the usefulness of prostanoids is uncertain.
( 2b, B-R )
- In patients with CLTI for whom revascularization is not an option, arterial intermittent pneumatic compression devices may be considered to augment wound healing or ameliorate ischemic rest pain.
( 2b, B-NR )
- In patients with CLTI for whom arterial revascularization is not an option and a lack of outflow to the foot is observed, venous arterialization may be considered for limb preservation.
( 2b, B-NR )
10.3.4. Amputation for CLTI
- In patients with CLTI who require amputation, evaluation should be performed by a multispecialty care team (Table 15) to assess for the most distal level of amputation that facilitates healing and provides maximal functional ability.
( 1, B-NR )
- In patients with CLTI, primary amputation is indicated when life over limb is the prevailing consideration and clinical factors suggest the threatened limb to be the cause of the patient’s instability (eg, ischemia, metabolic derangement, or advanced infection).
( 1, C-EO )
- In patients with CLTI, a patient-centered approach using objective classification of the threatened limb, patient risk, and anatomic pattern of disease combined with patient and family goals is recommended to identify those patients in whom primary amputation or palliative management is appropriate.
( 1, C-EO )
- In patients with CLTI undergoing minor amputation (ie, inframalleolar level), a customized program of follow-up care that can include local wound care, pressure offloading, serial evaluation of foot biomechanics, and use of therapeutic footwear is recommended to prevent wound recurrence.
( 1, C-EO )
- For patients with CLTI, retrospective assessment of institutional outcomes (including amputation) with objective limb threat classification tools can be useful for quality improvement.
( 2a, C-EO )
11. Acute Limb Ischemia
11.1. Initial Clinical Evaluation and Diagnostic Approach to ALI
- Patients with ALI should be evaluated on an emergency basis by a clinical with sufficient experience to assess limb viability and implement appropriate therapy.
( 1, C-EO )
- In patients with suspected ALI, the initial clinical evaluation should rapidly assess limb viability and potential for salvage and can be achieved without noninvasive imaging (ie, duplex ultrasound, CTA, or MRA).
( 1, C-LD )
- In patients with ALI who have a complicated history of revascularization procedures, it may be reasonable to obtain noninvasive imaging (ie, duplex ultrasound, CTA, or MRA) before deciding to proceed with revascularization.
( 2b, C-EO )
11.2. Management of ALI
11.2.1. Revascularization for ALI
- In patients with ALI and a salvageable limb, revascularization (endovascular or surgical, including catheter-directed thrombolysis) is indicated to prevent amputation.
( 1, A )
- In patients with ALI and a salvageable limb who are treated with catheter-directed thrombolysis, adjunctive revascularization (ie, endovascular, or surgical) procedures can be useful.
( 2a, C-EO )
- In patients presenting with ALI from chemotherapeutic or prothrombotic viral states, it may be reasonable to take a more deliberate planning strategy before engaging in a definitive revascularization or medical treatment plan.
( 2b, C-LD )
- In patients with ALI with a nonsalvageable limb, revascularization of nonviable tissue should not be performed.
( 3 - Harm, C-EO )
11.2.2. Adjunctive Therapies to Minimize Tissue Loss in ALI
- Patients with ALI should be monitored and treated for compartment syndrome with fasciotomy after revascularization (endovascular or surgical, including catheter-directed thrombolysis) to prevent the sequelae of reperfusion injury and need for amputation.
( 1, C-EO )
- In patients with ALI with a threatened but salvageable limb (ie, category IIa or IIb), prophylactic fasciotomy is reasonable based on the clinical findings.
( 2a, B-NR )
- In patients with ALI and prolonged ischemia in whom revascularization (endovascular or surgical, including catheter-directed thrombolysis) is performed, concurrent and early amputation can be beneficial to avoid the morbidity of reperfusion.
( 2a, C-EO )
11.2.3. Anticoagulation for ALI
- In patients with ALI, regardless of cause or anatomic level of occlusion, systemic anticoagulation with unfractionated heparin should be administered on diagnosis unless contraindicated.
( 1, C-EO )
11.3. Diagnostic Evaluation for the Cause of ALI
- In patients with ALI, a comprehensive medical history and physical examination should be performed to determine the cause of thrombosis or embolization.
( 1, C-EO )
- In patients with ALI, testing for a cardiovascular cause of thromboembolism can be useful.
( 2a, C-LD )
12. Longitudinal Follow-Up of PAD
General Principles
- In patients with PAD, with or without revascularization, longitudinal follow-up with routine clinical evaluation, including assessment of limb symptoms and functional status, lower extremity pulse and foot assessment, and progress of risk factor management is recommended.
( 1, C-EO )
- In patients with PAD, coordination of care among clinicians to improve the management of PAD and comorbid conditions and to optimize patient outcomes is recommended.
( 1, C-EO )
Functional Status and QOL
- In patients with PAD, with or without revascularization, periodic assessment of functional status as well as overall health-related QOL as a component of longitudinal follow-up is recommended.
( 1, B-NR )
Medical Therapy
- In patients with PAD, long-term use of GDMT to prevent MACE and MALE is recommended.
( 1, A )
Postrevascularization Follow-Up
- In patients with PAD who have undergone lower extremity revascularization (ie, surgical and/or endovascular), longitudinal follow-up that includes periodic clinical evaluation of lower extremity symptoms and pulse and foot assessment is recommended.
( 1, C-LD )
- In patients with PAD who have undergone lower extremity revascularization (ie, surgical, endovascular, or both) with new lower extremity signs or symptoms, ABI and arterial duplex ultrasound is recommended.
( 1, C-LD )
- In patients with PAD who have undergone infrainguinal, autogenous vein bypass graft(s) without new lower extremity signs or symptoms, it is reasonable to perform ABI and arterial duplex ultrasound surveillance within the first 1 to 3 months postprocedure, then repeat at 6 and 12 months, and then annually.
( 2a, B-R )
- In patients with PAD who have undergone endovascular procedures without new lower extremity signs or symptoms, it is reasonable to perform ABI and arterial duplex ultrasound surveillance within the first 1 to 3 months postprocedure, then repeat at 6 and 12 months, and then annually.
( 2a, C-LD )
- In patients with PAD who have undergone infrainguinal, prosthetic bypass graft(s) without new lower extremity signs or symptoms, the effectiveness of ABI and arterial duplex ultrasound surveillance is uncertain.
( 2b, B-NR )
Telehealth
- For patients with PAD, telehealth can be an alternative mode for vascular evaluation and management and longitudinal follow-up, but the use of these visits should be consistent with the urgency of presenting symptoms.
( 2a, C-LD ) Class of Recommendations and Level of Evidence
COR and LOE are determined independently (any COR may be paired with any LOE).
A recommendation with LOE C does not imply that the recommendation is weak. Many important clinical questions addressed in guidelines do not lend themselves to clinical trials. Although RCTs are unavailable, there may be a very clear clinical consensus that a particular test or therapy is useful or effective.
* The outcome or result of the intervention should be specified (an improved clinical outcome or increased diagnostic accuracy or incremental prognostic information).
† For comparative-effectiveness recommendations (COR I and IIa; LOE A and B only), studies that support the use of comparator verbs should involve direct comparisons of the treatments or strategies being evaluated.
‡ The method of assessing quality is evolving, including the application of standardized, widely used, and preferably validated evidence grading tools; and for systematic reviews, the incorporation of an Evidence Review Committee.
COR indicates Class of Recommendation; EO, expert opinion; LD, limited data; LOE, Level of Evidence; NR, nonrandomized; R, randomized; RCT, randomized controlled trial.