Peripheral Artery Disease Therapeutics Flashcards
Define peripheral artery disease
Atherosclerotic obstruction of LARGE arteries
- can affect renal artery, mesenteric artery
- not within the coronary, aortic or brain vessels
When is ACE contraindicated in PAD?
Bilateral renal stenosis
What are possible symptoms of lower extremity PAD
Pain/discomfort
- Intermittent claudication: fatigue/discomfort/cramping/pain/numbness with exercise
- can be limping (typically buttock, thigh, calf)
- resolves with rest
- Leg ulcers
May be asymptomatic
What are risk factors for PAD? (4)
- 70+
- 50-69 with history of smoking and diabetes
- Under 50 with diabetes + (one other risk factor like HTN, dyslipidemia, smoking)
- other atherosclerotic diseases
What does the physical exam of PAD look like?
- Cool skin temp
- shiny skin
- thick toe nails
- lack of hair on legs
- weak peripheral pulses
- stiff muscles with pain
- sores/ulcers are slow to heal
What is the most common indicator of PAD? How is it calculated
Ankle-brachial index=
highest SBP in the leg / highest SBP in the arm
Interpret the ankle-brachial index.. what ABI numbers mean the following
non-compressible calcified vessel
normal
borderline
mild PAD
moderate PAD
Severe PAD
non-compressible calcified vessel: Over 1.4
normal: 1-1.4
borderline: 0.91- 0.99
mild PAD: 0.7 - 0.9
moderate PAD: 0.4-0.7
Severe PAD: under <0.4
When is the ABI test unreliable? (4)
- In patients with arterial calcification
- diabetes
- renal failure
- heavy smokers
What reduces the sensitivity of the ABI?
Falsely elevated ankle pressure
- results in false negatives
- will lead to missed diagnoses of PAD, despite it being there
What walking time to claudication indicate the following
Severe
moderate
mild
Severe: <1/2 city block (50m)
Moderate: 0.5-1 city block (50-100m)
Mild: >1 city block (>100m)
What lab tests are done for PAD
- FBG, SCr, lipid profile
- Hgb, Hct, platelet count
- D-dimer (Special for PAD): to gauge amount of blockage in peripheral arteries
- CRP inflammatory markers
- In severe cases: invasive angiography to prepare for possible angioplasty/surgial revascularization
What is the most effective therapy for PAD
Exercise
What are the benefits of exercise therapy
increases average walking time to 180% and max walking time to 120%
T/F combination between percutaneous transluminal angioplasty (PTA) and exercise is better than either intervention alone
True
What are the benefits of weight loss in PAD
- Longer time to symptoms
- Effort-related calf pain symptoms improve
What is recommended for symptomatic PAD? what ABI score?
Low dose ASA
- regardless of ABI score
When are dual antiplatelets recommended in PAD
Symptomatic PAD who are high CV risk (DM, dyslipidemia, HTN, CKD) and not at increased risk of bleeding
if they have ACS/MI in the last 12-30 months
When are antiplatelets considered in asymptomatic individuals?
ABI LESS than or equal to 0.90
no benefit establish in ABI for 0.90-0.99
What are benefits of statins in PAD? What are there no effects in?
Improves endothelium-mediated vasodilation and anti-inflammatory effetcs
Benefits
- in total walking distance
No benefits in
- overall mortality
- ABI
Benefits of ACE in PAD?
HOPE
- ramipril decreased risk of MI/CVD death
- may reduce symptoms
Which BB should you use for PAD? What is the concern?
Concern (theoretical):
- if alpha-1 receptors are left without blocking -> vasocontricting effects are inhibited -> can risk worsening PAD
Solution: If using BB in PAD, use one with Alpha-blocking activity ( Labetalol)
Are CCB good for PAD? Why?
No, due to “steal phenomenon”
Patient with PAD has poor perfusion to the peripheries, adding in a CCB/direct vasodilator will reduce the blood flow further to arteries with PAD “blood is stolen by earlier arteries”
Cilostazol
class
benefit
CI?
PDE3 inhibitor –> inc cAMP
- favourable effect on platelets
- vasodilation
- modfiication of lipid profile
- reduced chronic inflammation
benefit: Inc in maximal walking distance
CI: in systolic HF
*not available in canada
Pentoxifylline
Benefit?
No consistent data for benefits
No improvement in ABI
