#260 Peripheral Artery Disease with Dr. Vlad Lakhter

March 8, 2021 | By Paul Williams

A painless walk through the diagnosis and management

Peripheral artery disease is one of those diagnoses that you know about, but maybe don’t feel comfortable diagnosing and managing.  Listen as our esteemed guest Dr. Vladimir Lakhter @VladLakhter (Temple Health) talks us through its diagnosis and management.  Dr. Lakhter gives us a straightforward framework for categorizing and triaging peripheral artery disease and talks us through the important components of medical management and who benefits from revascularization. 

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Credits

• Written and produced by: Jake Kieserman and Paul Williams MD, FACP
• Infographic: Edison Jyang
• Cover Art: Kate Grant MBChB DipGUMed
• Hosts: Stuart Brigham MD; Matthew Watto MD, FACP; Paul Williams MD, FACP   
• Editor: Emi Okamoto MD (written materials); Clair Morgan of nodderly.com
• Guest: Vladimir Lakhter, DO

CME Partner: VCU Health CE

The Curbsiders are partnering with VCU Health Continuing Education to offer FREE continuing education credits for physicians and other healthcare professionals. Visit curbsiders.vcuhealth.org and search for this episode to claim credit. See info sheet for further directions. Note: A free VCU Health CloudCME account is required in order to seek credit.

Time Stamps*

*Note: Time Stamps refer to ad-free version. 

• Intro, disclaimer, guest bio- 00:33
• Guest one-liner- 3:25
• Dr. Lakhter book recommendations- 5:36
• Case from Kashlak- 8:35
• Definition and background for PAD- 10:25
• Classification schema for PAD- 12:45
• The physical examination- 21:05
• ABIs and PVR in the diagnosis of PAD- 33:50
• Exercise program for PAD-  46:08
• Medication therapy-  52:05
• Revascularization- 1:02:50
• Outro- 1:08:45

Peripheral Artery Disease Pearls

1. The initial step in the identification of peripheral artery disease is to identify whether patients have critical limb ischemia or claudication.
2. Risk factor identification and mitigation are the critical first steps in the management of peripheral artery disease.
3. Ongoing tobacco cessation is mandatory for patients with peripheral artery disease who smoke.
4. A structured exercise program should be offered as an additional therapy for all patients with peripheral artery disease.
5. Aspirin and high-dose statin therapies should be used in all patients with peripheral artery disease.
6. Revascularization should be considered for patients with peripheral artery disease who continue to have lifestyle-limiting symptoms despite exercise and medical therapy.

Peripheral Artery Disease Notes

Definitions and background

• Peripheral artery disease: atherosclerotic involvement of the peripheral arteries that causes flow-limiting blockages in the peripheral arterial circulation
  • Most commonly refers to lower extremities, but also includes carotid and renal arteries as well
• 30-50% of patients with coronary artery disease will have comorbid peripheral artery disease (Poredos, 2007)
• Common risk factors include older age, tobacco use, hypertension, diabetes, hyperlipidemia, obesity, and family history
• The Fontaine and Rutherford classifications are used to classify peripheral artery disease (Hardman, 2014)
  • Both systems include a classification for asymptomatic disease, and both  have progressive grades for worsening claudication
  • Both have specific classifications for critical limb ischemia
• In the initial evaluation, the most important branch points are determining asymptomatic versus symptomatic disease
• If symptomatic disease is found, the next important branch point is determining if this is claudication or critical limb ischemia
  • Claudication is any pain that occurs with exertion and resolves with rest
  • Critical limb ischemia is characterized by rest pain, nocturnal pain, ulceration, or gangrene
• Critical limb ischemia warrants more urgent revascularization, whereas more conservative management is used initially for claudication
• Typical claudication is characterized by exertional symptoms, and this can include the buttock, hip, or thigh (suggesting aortoiliac disease) and calf or foot (suggesting femoral popliteal or tibial disease)
  • The location is determined by the level of disease
• Pseudoclaudication can occur with sciatic disease or structural back disease, but the symptoms are usually not exertional and are classically positional
  • The shopping cart sign, characterized by relief of pain by leaning forward, is suggestive of pseudoclaudication

Physical Examination

• The physical examination often begins with blood pressure taken in both arms
• Pulses assessment can give clues to the vascular level of disease
  • Pulses are graded from 0-3
    • 0 = absent
    • 1 = diminished
    • 2 = normal
    • 3 = bounding
  • Bounding pulses are suggestive of an aneurysm or high pulse pressure like in aortic regurgitation
  • Absent pulses are suggestive of disease at a higher level of the vascular tree
• Arterial ulcers can be seen in the toes
  • “Kissing ulcers” are found on the inner aspects of the toes

Initial Work-up of Peripheral Artery Disease

• Typically starts with testing of the ankle-brachial index (ABI)
  • This is calculated by determining the systolic blood pressure at the brachial artery and at the level of the posterior tibial and dorsalis pedis (Aboyans, 2012)
  • The value given is the posterior tibial or dorsalis pedis blood pressure (whichever is higher) divided by the brachial systolic pressure 
    • A value of 1.0-1.4 is considered normal
    • Anything less than 0.9 is abnormal
  • Exercise ABI can be considered if the index is normal but suspicion remains high
• The level of disease can be determined by increasing the number of levels checked with the ABI or by doing a pulse volume recording
• The pulse volume recording is measured at varying arterial levels, and the waveform is evaluated (for decreased amplitude, absent dicrotic notch) to determine possible level of pathology

Initial Management of Peripheral Artery Disease

• Screen and manage any comorbid risk factors, like hypertension, diabetes, hyperlipidemia, and tobacco use
  • A discussion of tobacco cessation is absolutely requisite for patients who smoke
• An exercise program is critical to the management of claudication
  • The CLEVER trial demonstrated that a supervised exercise program was just as effective as revascularization for patients with claudication from aortoiliac disease
  • Patients can attend an outpatient structured exercise program for up to 3 times per week for 12 weeks
    • This should be offered before revascularization is considered
    • If access is an issue, patients can be instructed to walk for 30-40 minutes, walking until claudication symptoms occur, and then resting until symptoms resolve
  • This likely works by a combination of ischemic preconditioning (conditioning tissues to less blood flow) and the development of collateral circulation
• All patients with peripheral artery disease should be on aspirin 81 mg, if possible (Gerhard-Herman, 2017)
  • This reduces adverse limb events and adverse cardiovascular events such as stroke and heart attack
• Patients with peripheral artery disease should also be prescribed a high dose statin (either 80 mg atorvastatin or 40 mg rosuvastatin)
• Cilostazol has been shown to increase claudication-free walking distance in patients with claudication symptoms from peripheral artery disease (Bedenis, 2014)
  • Contraindicated in patients with heart failure
  • Headache, diarrhea, and palpitations are potential side effects
• Generally, dual antiplatelet therapy is not specifically indicated for most patients with peripheral artery disease of the lower extremities
  • The CHARISMA trial showed some benefit for high-risk patients (e.g. for those with multiple interventions in the past)
  • Dr. Lakhter will place patients on clopidogrel for 30 days following revascularization
  • There is significant practice variation in this realm
• The VOYAGER trial showed that rivaroxaban at a dose of 2.5 mg twice daily plus aspirin in patients who had undergone lower-extremity revascularization was associated with a significantly lower incidence of limb and atherosclerotic events
  • This was at the expense of a significantly increased bleeding risk
  • There has not been broad uptake in the prescription of direct oral anticoagulants at the time of this episode
• The WAVE trial did not show benefit to adding warfarin to antiplatelet therapy

Revascularization for Peripheral Artery Disease

• Revascularization should be considered for patients who have lifestyle–limiting symptoms of claudication despite maximal medical therapy and exercise program
• Determining the specific vascular level is critical in determining the intervention
• CT angiography of the abdomen and pelvis is a good initial modality when planning an intervention
  • This can be limited by calcification and a “blooming artifact”
• Other modalities include MR angiography or interventional angiography
• The determination to pursue endovascular versus surgical intervention is determined by patient preference, risk factors, and location of the anatomical lesion

Links*

1. Mr. Nosey by Roger Hargreaves
2. Alma’s Matters by Ido Weinberg
3. The House of God by Samuel Shem

Goal

Listeners will outline the diagnosis and medical management of peripheral artery disease, as well as identify who will benefit from revascularization

Learning objectives

After listening to this episode listeners will…  

1. Differentiate between claudication and critical limb ischemia
2. Recognize and mitigate important risk factors for peripheral artery disease
3. Perform the appropriate physical examination to identify and stratify peripheral artery disease
4. Order appropriate initial diagnostic tests for peripheral artery disease
5. Identify the importance of an exercise program in the early management of claudication
6. Outline the appropriate medication management of peripheral artery disease
7. Recognize which patients with peripheral artery disease are appropriate for revascularization

Disclosures

Dr. Lakhter reports no relevant financial disclosures. The Curbsiders report no relevant financial disclosures. 

Citation

Kieserman JM, Williams PN, Brigham SK, Watto MF. “#260 Peripheral Artery Disease with Dr. Vlad Lakhter”. The Curbsiders Internal Medicine Podcast. http://thecurbsiders.com/episode-list Final publishing date March 8, 2021.