B P5 C43 Peripheral Artery Diseases Flashcards
________________ generally refers to acute or chronic obstruction of the arteries supplying the lower or upper extremities that, when severe, results in downstream ischemia and potentially tissue loss.
Peripheral artery disease
Most often caused by atherosclerosis, PAD may also result from thrombosis, embolism, vasculitis, fibromuscular dysplasia (FMD), or entrapment.
__________________, _______________, __________________ account for about 75% of the risk of developing PAD
Smoking, type 2 diabetes mellitus (DM), hypertension, and hypercholesterolemia
________________ results from an oxygen (O2) supply mismatch analogous to angina in patients with stable angina
Intermittent claudication
Patients with intermittent claudication may have single or multiple occlusive lesions in the arteries supplying the limb.
Blood flow and leg O2 consumption are normal at ______ , but the obstructive lesions limit blood flow and O2 delivery during exercise such that the metabolic needs of the exercising muscle outstrip the available supply of O2 and nutrients
Rest
There is considerable heterogeneity in patterns of occlusive disease including medial artery calcification and a predominance of below knee disease particularly in patients with _____________ and ___________
Diabetes and/or CKD
The cardinal symptoms of PAD include limb pain either with exercise (_______________________) or at rest
Intermittent claudication
________________refers to a pain, ache, sense of fatigue, or other discomfort that occurs in the affected muscle group with exercise, particularly walking, and resolves with rest.
Intermittent claudication
Symptoms or tissue loss occur at ______ in patients with CLI.
Rest
Typically, patients complain of pain or paresthesias in the foot or toes of the affected extremity. This discomfort worsens with leg elevation and improves with leg dependency, as might be anticipated by the effect of gravity on perfusion pressure. The pain can be particularly severe at sites of skin fissuring, ulceration, or necrosis.
Characteristic of a venous ulcer
Localizes near the medial malleolus Irregular border
Pink base with granulation tissue
Produce milder pain
Characteristic of a neuropathic ulcer
Occur at sites of pressure or trauma, usually on the sole of the foot
Ulcers are deep
Frequently infected,
Mot generally painful because of the loss of sensation
Physical findings of ____________ and _________ increase the likelihood of PAD
Pulse abnormalities and bruits
_____________ are often a sign of accelerated blood flow velocity and flow disturbance at sites of stenosis. A
Bruits
Signs of chronic low grade ischemia vs severe lim ischemia
Chronic low-grade ischemia - hair loss, dystrophic, thickened and brittle toenails, smooth and shiny skin, and atrophy of the subcutaneous fat of the digital pads
Severe limb ischemia - cool skin and may also have petechiae, persistent cyanosis or pallor, dependent rubor, pedal edema resulting from prolonged dependency, skin fissures, ulceration, or gangrene.
Charcteristics of arterial ulcers
Pale base
Irregular borders
Involve the tips of the toes or the heel of the foot or develop at sites of pressure
Vary in size and may be as small as 3 to 5 mm.
Give the Fontaine classification
Presence of rest and nocturnal pain
Fontaine III
Give the Rutherford classification
Ischemic rest pain
Rutherford Grade II Category 4
_____________________ advanced PAD with rest pain, gangrene, or ulceration of greater than 2 weeks.
Chronic limb threatening ischemia
__________ acknowledges and evaluates the m tifactorial nature of wounds in patients with PAD including wound characteristics, infection, and ischemia
WIFI (Wound, Ischemia, and Foot Infection)
Measurement of SBP along sequential segments of each extremity is one of the simplest noninvasive measures for ascertaining the presence and severity of stenoses in the peripheral arteries.
Segmental pressure measurement
SBP may be higher in the more distal vessels than in the aorta and proximal vessels because of _____________________________
A mplification and reflection of BP waves.
Approximately _______ of the cross-sectional area of the aorta must be narrowed before a pressure gradient develops.
In smaller vessels, such as the iliac and femoral arteries, a _____________ decrease in cross-sectional area will cause a resting pressure gradient sufficient to decrease SBP distal to the stenosis.
Aorta - 90%
Iliac and Femoral, smaller vessels - 70% to 90%
A BP gradient in excess of _____________ between successive cuffs is generally used as evidence of arterial stenosis in the LE
20 mm Hg
A gradient of _________ indicates a stenosis between sequential cuffs in the upper extremity.
10 mm Hg
SBP in the toes and fingers is approximately _______ of SBP at the ankle and wrist, respectively, because pressure diminishes further in the smaller distal vessels.
60%
Identify the location of the stenosis
A pressure gradient is present between the left upper and lower thigh cuffs, lower thigh and calf cuffs, and calf and ankle cuffs, consistent with multisegmental disease affecting the femoral-popliteal and tibial arteries.
__________ ratio of SBP measured at the ankle to SBP measured at the b chial artery.
Ankle-Brachial Index
Classification of ABI
Normal - 1.00 - 1.40
Borderline - 0.91 - 0.99
Abnormal 0.9 or less
An ABI of 0.90 or lower has a specificity of 83% to 99% and a sensitivity of 69% to 73% in detecting stenoses greater than 50%
Patients with symptoms of leg claudication often have an ABI ranging from _____________, and patients with CLI usually have an ABI _____________
0.5 to 0.8
0.4 and lower
An ankle SBP less than _____________ predicts poor ulcer healing.
55 mm Hg
An ABI higher than _______ indicates a noncompressible artery, and the test is not informative for either confirming or excluding PAD
1.40
In case of noncompressibel arteries, _____________ should be used
Ratio of _________ or higher reflects normal perfusion pressure
Toe-brachial index
Ratio of 0.70 or higher reflecting normal perfusion pressure
________________ can be used to evaluate the clinical s icance of peripheral artery stenoses and provide objective evidence of the patient’s walking capacity.
Treadmill Exercise Testing
This provocative test should be considered in patients with risk factors and symptoms suggestive of vascular claudication but with normal resting ABI, as may occur in those with proximal disease.
The ___________________ is when symptoms of claudication first develop, and the ________________ occurs when the patient can no longer continue walking because of severe leg discomfort.
Claudication onset time
Peak walking time
A ______________________ in the ABI after exercise in a patient whose walking capacity is limited by claudication is considered diagnostic and implicates PAD as a cause of the patient’s symptoms.
25% or greater decrease
BP increase that occurs during exercise should be the same in both the upper and the lower extremities, with a constant ABI of 1.0 or greater being maintained. In the presence of peripheral artery stenoses, however, the ABI decreases because the BP increase observed in the arm is not matched by a comparable increase in ankle BP.
_____________ graphically illustrates the volumetric change in a segment of the limb that occurs with each pulse.
Pulse Volume Recording
Normal pulse volume contour
Sharp systolic upstroke rising rapidly to a peak, a dicrotic notch, and a concave downslope that drops off gradually toward the baseline
Stenotic pulse contour
Loss of the dicrotic notch, a slower rate of rise, a more rounded peak, and a slower descent.
The amplitude becomes lower with increasing severity of disease, and the pulse wave may not be recordable at all in a critically ischemic limb.
Normal doppler waveform
Rapid forward-flow component during systole
Transient flow reversal during early diastole
Slow anterograde component during late diastole
Stenotic doppler flow
Deceleration of systolic flow, loss of the early diastolic reversal, and diminished peak frequencies
Arteries in a limb with critical ischemia may not show any Doppler frequency shift.
provides a direct, noninvasive means of assessing both the anatomic characteristics of peripheral arteries and the functional significance of arterial stenoses
Duplex Ultrasound Imaging
A ___________________ in peak systolic velocity at the site of an atherosclerotic plaque indicates a 50% or greater stenosis
Twofold or greater increase
A threefold increase in velocity suggests a ______________ stenosis
75% or greater
______________ has its greatest usefulness in the evaluation of s tomatic patients to assist in decision making before endovascular and surgical intervention or in patients at risk for renal, allergic, or other complications during conventional angiography.
Magnetic Resonance Angiography
permits imaging of peripheral arteries with excellent spatial resolution during a relatively short time and with limited amounts of radiocontrast material
Computed tomography
Those with the most severe symptoms of PAD, notably those with _______, have the worst prognosis with high rates of amputation and mortality.
CLI
Class I recommendations in the medical tx for PAD
Treatment with a statin medication is indicated for all patients with PAD.
Antihypertensive therapy should be administered to patients with hypertension and PAD to reduce the risk of MI, stroke, heart failure, and cardiovascular death.
Patients with PAD who smoke cigarettes or use other forms of tobacco should be advised at every visit to quit.
Patients with PAD should have an annual influenza vaccination
Management of diabetes mellitus in the patient with PAD should be coordinated between members of the health care team
Class 1 recommendation regarding antiplatelet tx in PAD
Antiplatelet therapy with aspirin alone (range, 75–325 mg/day) or clopidogrel alone (75 mg/day) is recommended to reduce MI, stroke, and vascular death in patients with symptomatic PAD.
The _____________ trial compared clopidogrel with aspirin in reducing ischemic events in patients with recent myocardial infarction, recent ischemic stroke, or PAD. Overall, clopidogrel reduced vascular death, myocardial infarction, or stroke by 8.7% versus aspirin. 84 Notably, among the 6452 patients in the PAD subgroup, clopidogrel treatment appeared to be associated with a greater 23.8% relative risk reduction.
CAPRIE trial (Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events)
Data demonstrate that antiplatelet monotherapy reduces CV risk in patients with _______________, but it is of uncertain benefit in those with a marginally low ABI and no symptoms.
Symptomatic PAD
The most common application of DAPT in patients with PAD is in the _____________________ where benefits after endovascular intervention have been largely extrapolated from the coronary setting
Postintervention setting
The only randomized trial of DAPT after revascularization was the ___________ trial; DAPT versus aspirin did not reduce the primary composite endpoint of graft occlusion, revascularization, amputation, or death in patients undergoing belowknee bypass surgery for PAD and moderate or severe bleeding was increased.
CASPAR (Clopidogrel and Acetylsalicylic Acid in Bypass Surgery for Peripheral Artery Disease)
Overall, there are data to support antiplatelet monotherapy for MACE reduction in PAD, but data for MALE benefit are mixed. The efficacy of DAPT is supported for the reduction of MACEs and MALEs in patients with both PAD and CAD (polyvascular disease), although there is increased bleeding risk.
Medical tx for symptomatic PAD with prior revascularization
Smoking cessation, diet, exercise
ASA + Rivarixaban (if low bleeding risk)
High intensity statin +/- Eze and/or PCSK9i
ACEi for HPN
GLP 1 or SGLT2 for DM
Exercise
Cilostazol
Arteriographic findings in TAO
Segmental occlusion of small and medium arteries, absence of atherosclerosis, and corkscrew collateral vessels circumventing the occlusion
These same findings, however, can occur in patients with scleroderma, SLE, mixed connective tissue disease, and antiphospholipid antibody syndrome.
Appears as a tubular stenosis, is less common, and is pathologically associated with medial hyperplasia and periarterial hyperplasia
Focal FMD
Classify ALI
Sensory loss ankle and above, moderate weakness, absence of pulses
IIB - Immediately Threatened
Initial treatment option for patients with either category I or II ALI if they have no contraindication to thrombolysis.
Catheter-directed intra-arterial thrombolysis plus thrombectomy
The most notable clinical features of atheroembolism involving the extremities include painful cyanotic toes, called _________________
“blue toe syndrome”
