Chapter 105 - Lower extremity arterial disease - medical management and decisions Flashcards
PAD prevalence overall and age distributed
4.3% 40-49 years: 0.9% 50-59 years: 2.5% 60-69 years: 4.7% >69 years: 14.5%
5 years course of intermittent claudication
amputation 1-7% deterioration 25%
CLTI cardiovascular mortality in 1, 5 and 10 years
1 year: 12% 5 years: 42% 10 years: 65%
Chronic subclinical LE ischemia definition
ABI < 0.9 without IC or CLTI usually due to limitation of other comorbidity
Ambulation rate of decline in I.C.
8.4 m/yr
Structured exercise survival benefit in 5 years
80.5% vs 56.7%
ACC/AHA recommendation on exercise
30-45 min x 3-4/week for 12 weeks
Percentage of patients with I.C. where exercise therapy can be completed
1/3
Two FDA approved drugs for PAD
1) Pentoxifylline (Trental) 2) Cilostazol (Pletal)
Cilostazol MOA
Phosphodiesterase III inhibitor –> increase cAMP 1) SMC relaxation 2) inhibit platelet aggregation 3) decrease SMC proliferation 4) decrease TG, increase HDL 5) increase VEGF
Effect of cilostazol
1) increase walking distance by 50% 2) increase quality of life
Side effects of cilastazol
1) headache 2) diarrhea and other GI symptoms 3) CHF exacerbation 4) interact with cytochrome p450 system
Contraindication of cilastazol
CHF
Dose of Cilostazol
100 mg po BID start slow titrate up
Cilostazol vs pentoxifylline
Cilostazol better at increasing walking distance
TASC definition
Trans Atlantic Inter Society Consensus
TASC purpose
1) gauge extent of angiographic disease 2) aid in decision making
What % of CLTI post-op bypass does not show clinical improvement despite graft patency
10%
Specific names of QOL PAD surveys
1) SF36 2) Nottingham Health Profile
Endpoint in I.C. treatment
Quality of life
Endpoint for CLTI based on Taylor et al in Rutherford class 5/6 bypass success
1) Patent until wound heal 2) Limb salvage 1 year 3) ambulatory 1 year 4) survival 6 months Total probability 44%
TASC and TASC II years
TASC 2000 TASC II 2007
Run off score
0 < 20% stenosis 1: 20-50% stenosis 2: 50-99% stenosis 2.5: < half occluded 3: > half occluded
Calcium score in PAD anatomy
0: none 1: < 25% 2: 25-50% 3:> 50% circumference
Lesion length category
Short < 6cm Intermediate 7-10cm Long > 10cm
I.C. risk of amputation per year and cardiac death
Amputation 1% Cardiac death 3-5%/year
Smoking cessation in I.C.
1) unclear if increases walking distance 2) reduces cardiovascular events
Cilostazol cannot be used in this % of population and why
15% CHF
ACC/AHA guideline for treatment of PAD
1) antiplatelet 2) cilostazol Class I evidence
CLEVER study on PAD
Claudication: exercise vs endoluminal revascularization 6 month: walking time best in exercise > stent > drugs QOL: best in stent > exercise > drugs
Amputation in I.C. patients post-op from revasc attempt
1.6% in 1 year
Medical therapy only in PAD effectiveness
30%
Johnson characteristics most ammenable to perc endo treatment
1) focal lesion 2) large diameter 3) adequate outflow
CIA angioplasty patency in 5 year
70%
% of IC that progress to CLTI
< 5%
Typical CLTI symptom duration and pressure measurement for diagnosis
2 weeks of symptoms Ankle pressure < 50 toe pressure < 30
CLTI outcomes in amputation and death 1 year
25% amp 25% death
Medical treatment only in CLTI amp rate
40% amputation at 6 months
Decision in CLTI
1) medical vs intervention 2) amputation vs revasc 3) endo vs open
Rate of primary amputation in CLTI
10-40%
Unreconstructable CLTI rate
60%
Factors that increase BKA healing
1) well-controlled comorbidities 2) palpable femoral 3) warm calf 4) no infection
Immediate post-op prosthesis benefits
1) reduce revision (5.4 vs 27.6%) 2) 86% independent amublation rate 3) time to ambulation 15.2 days
BASIL trial on 1 year amputation-free survival in bypass vs endo then bypass
Endo then bypass 40% Primary bypass 70%
Situational perfusion enhancement
For healing wounds temporarily
BASIL key points
1) 450 patients randomized to bypass vs POBA 2) 6 months AFS 21 vs 26% 3) 2 year surgery is better in AFS and survival
BASIL 2
vein bypass vs best endo 600 patients primary outcome: amputation free survival
BEST CLI
best endo vs best surgery 2100 patients primary outcome: MALE
Mortality following LE bypass
1.8%
Cardiac complication following LE bypass
7.2%
Angiogenesis for CLTI possibilities
1) VEGF 2) HGF 3) stem cell
Other research in CLTI
1) Hypoxia inducible factor pathway stimulation (prolyl-4-hydroxylase inhibitor, thioredoxin system, peroxome proliferator activated receptor gamma coactivator 1 alpha protein, micro RNA, oligonucleotide) 2) therapeutic ultrasound 3) immune modulation 4) viral gene transfer 5) antibiotic therapy 6) cell-free oxygen delivery vectors
Decision tree analysis in revascularization of CLTI
1) revascularization vs primary amputation gives 1.1 QALYs 2) revascularization vs medical only gives 1.2 QALYs gain 3) revascularization least costly per QALY if 1 month patency > 11%
TASC C lesion decision tree
Stent if 1) primary patency > 32% in 5 years 2) age > 80 3) mortality periop of bypass > 6%
Pharmacologic treatment of claudication part 1
Pharmacologic treatment of claudication part 2
CLTI endpoints different types and definitions
Taylor’s probability of failure after bypass when clinical condition is present
2 factors: 33% success
3 factors: 10% success
all 4 factors: 5% success
hyperlipidemia doesn’t count
TASC II aorto-iliac lesions
TASC II femoropopliteal lesions
Morbidity after bypass surgery
Comparison of different risk stratification scores in cardiovascular disease and PAD
