10/10/2015
1
Peripheral Vascular Disease
Ganesh Muthappan, MD, FACC
Disclosures
• I work for St. Charles Heart and Lung
Center
• I am trying to build a practice in central
Oregon
• I do own a small amount of St. Jude stock
as part of a retirement portfolia
– I use what I consider the best product
available for my patients (including a Volcano
corporation product where St. Jude and
Volcano compete)
What is Peripheral Vascular
Disease?• Any vascular disease that isn’t in the heart
• Areas of special concern include cerebral
arteries, mesenteric arteries, renal
arteries, and leg arteries
• Usually due to atherosclerosis, but may be
due to other disease as well (trauma,
autoimmune)
• Don’t pay as much attention to veins:
bypassess are generally easier to form
(with exceptions)
10/10/2015
2
Epidemiology
• Risk factors include diabetes, tobacco use,
renal disease, age
• Up to 30% prevalence in patients with
concomitant diabetes and tobacco use
• Incidence increasing over time
• Incidence increases with age; appx 15-
20% of persons older than 70 have LE
PAD
Natural History
• Poor prognosis: diagnosis can lead to
disease course modification
• 5 year mortality rate for patients with
intermittent lower extremity claudication is
30%
• 5 year amputation rate is 4%
• Continued smoking and poor diabetes
control portends very severe prognosis
Weitz et al. Circulation 1996; 94: 3026-49
Natural History
McDermott et alJ Gen Intern Med. 1994;9:445-44
Severity of peripheral arterial
disease, as measured by ABI, has a
strong correlation with mortality, as
well as hard cardiovascular
endpoints (stroke, heart attack)
10/10/2015
3
Lower Extremity Arterial
Disease
Symptoms of Lower Extremity
Claudication (Intermittent)
• Lower extremity claudication: crampy, achey
pain that comes on (or worsens) with exertion
and gets better with rest. Often unilateral
• Pseudoclaudication (spinal stenosis):
paresthetic pain that occurs both with standing
and with walking, relieved by sitting and/or
leaning forward. Almost always bilateral.
Climbing steps will often not bring on the
pain.
Classification of Claudication
10/10/2015
4
Diagnosis of Lower Extremity
Peripheral Arterial Disease
• Ankle Brachial Index
• Toe Brachial Index
• Walking ABI
• Lower Extremity Arterial Duplex
• CT/MR angiography
• The gold standard is invasive angiography
Ankle Brachial Index
• The higher of the DP or PT pressure for
each leg divided by the higher arm
pressure (brachial)
Normal 1.00 – 1.40
Borderline 0.91 – 0.99
PAD ≤ 0.90
Pain/Ulceration ≤ 0.60
Non-Compressible ≥ 1.40
ACC/AHA 2011 PAD Management Guidelines
Diagnostic Methods: Ankle-Brachial Index (ABI)
• The resting ABI should be used to establish the diagnosis of patients at high risk for PAD, defined as patients
- with exertional leg symptoms,
- with nonhealing wounds,
- who are 65 years and older,
- or who are 50 years and older with a history of smoking or diabetes.
10/10/2015
5
What does a Normal ABI Mean?
So what to do?
• In a patient with exertional angina,
treadmill stress test is much more
revealing than resting ECG/echo
• In a patient with exertional claudication,
treadmill ABI is much more revealing than
resting ABI
• Treadmill ABI: patient walks at 1-2 MPH at
10% incline for 5 minutes; if ankle
pressure decreases by 15 mmHg, then
positive
Duplex Ultrasonography
• Most common secondary test for LE PAD
at St. Charles
• 5-7.5 MHx transducer
• Painless
• >90% sensitivity and specificity
• Can be used to estimate severity of
disease
• May overestimate stenosis (especially
following interventions)
10/10/2015
6
CTA and MRA
• Highly sensitive and specific
• CTA uses iodinated contrast
• MRA may be limited by the presence of
clips, pacemakers/defibrillators
• I will often order prior to diagnostic
angiography/intervention learn the lay of
the land
• However, selective angiography is the
gold standard
Catheter Based Angiography
• Access is gained to the leg contralateral to
the one where intervention is planned
• A 5F or 6F sheath (2mm) is inserted into
the common femoral artery
• Pigtail catheter is advanced to the aortic
bifurcation and digital subtraction
angiography is performed
• Catheter is then worked over the
bifurcation and selective angiography is
performed
10/10/2015
7
How to Treat Lower Extremity PAD
• Lifestyle changes
• Prevent cardiac/cerebral
morbidity/mortality (aspirin, statin, ace
inhibitor)
• Decrease symptoms (exercise therapy,
cilostazole, endovascular intervention)
• Limb salvage (endovascular intervention,
open revascularization)
Exercise Therapy Works
• Monitored exercise program (treadmill walking)
• Control patients had a 60% decrease in walking
distance over the course of 6 months
• Exercise therapy patients had a 80%
improvement in walking distance over 6 months
• Insurance generally does not pay
Gardner AW, Poehlman ET. JAMA. 1995;274:975-
980.
Cilostazole
• Phosphodiesterase 3 inhibitor
• Has both antiplatelet as well as vasodilating
properties
• Increases walking distance by approximately
80% over placebo
• Often limited by side effects (nausea, diarrhea,
headaches). CONTRAINDICATED WITH LOW
EF
• 100 mg BID
• Approximately $120 for a month’s supply
10/10/2015
8
Endovascular Intervention
• CLASS IA indication for endovascular
intervention for lifestyle limiting claudication
when the patient has failed conservative
measures and/or there is a very favorable
risk/benefit ratio for endovascular intervention
(e.g focal aorto-iliac occlusive disease)
• Technology and technique continues to improve:
superficial femoral arterial disease is now just as
safe (or safer) than aorto-iliac disease
Aortoiliac Disease
• Symptoms in hips, buttocks, thighs
• Can occur in younger patients
– In patients in their 50s with claudication, I
think of aortoiliac disease first
– Often healthier than patients with PAD
involving more peripheral arteries
Open vs. Endovascular Approach
for Aorto-iliac disease
• Surgery is the gold standard. Excellent
success rate (80-90% at 5 years), but
carries 1-3% mortality in major trials (these
are sick patients!)
• Endovascular approach: good patency
(70%) at 5 years, similar morbidity and
mortality
• Endovascular technology improves every
year
10/10/2015
9
Procedural Considerations
• Usually ipsilateral access (if femoral artery
is patent)
• Retrograde wire
• Balloon angioplasty
• Stenting with either self expanding or
balloon expandable stents is often
preferred
• If truly aortoiliac disease, “kissing” stents
are often used
Sample Case
• Left external iliac lesion
• Left CFA approach
• Cross lesion with wire
• Angioplasty/stent
Femoropopliteal Disease
• This anatomical location is more prone to scarring/thrombosis
• Surgery has appx. 70% 5 year patency for reverse vein grafts, appx. 40% 5 year patency for PTFE grafts
• Endovascular approach: 70% 2 year patency for drug coated stent, 50% 2 year patency for angioplasty alone.
• Current generation of drug coated stents are being improved, and atherectomy/drug coated balloon success rates are still being tabulated (80% 2 year success rates)
• Endovascular approach carries less morbidity/mortality than open approach
10/10/2015
10
Procedural Considerations
• Usually contralateral access
• Crossover and place a sheath just
proximal to area of disease
• Cross disease with wire
• Deliver equipment
• Angioplasty alone is preferred, but stenting
often used as well
• Self expanding stents have greater
resiliency in this location
Sample Case 1
• 67 year old man with poorly controlled
diabetes, CAD s/p CABG, prior tobacco
use and ongoing marijuana (smoked) use.
• Referred for nonhealing ulcer x 3 months
with noxious smell.
• No palpable pulses on either foot
10/10/2015
11
Sample Case 1
Sample Case 1
Sample Case 1
• Post procedure had
booming dorsalis pedis
pulse
• Wound did heal several
months post procedure
(sugars in 200s)
• Angiogram 3 months later
of LLE did not show
significant popliteal
disease
10/10/2015
12
Sample Case 2
• 68 year old man with longstanding history of
tobacco use (ongoing), dyslipidemia, well
controlled diabetes, coronary artery disease s/p
CABG with EF 35%
• 6 months of left calf aching, initially >50 yards
but now 10 yards (can’t walk around his house
without having to stop and rest his calf)
• Had bilateral iliac stenting in March, but still with
left calf symptoms and now nonhealing ulcer
Sample Case 2
10/10/2015
13
• Patient with barely dopplerable pulse
before procedure, now had palpable pulse
after procedure
• Able to walk around house, but still limited
by pain with >100 yards of walking
So my patient has had a LE procedure
for claudication: what should I do?
• Aspirin 81 mg daily indefinitely
• Clopidogrel 75 mg daily for at least one month
(depending on intervention, complexity of stent
left behind)
– Bigger vessels with more flow are less likely to
thrombose
• Refer to PAD rehab if possible (the magic
unicorn)
• Encourage patient to walk
• Follow up exam/imaging at 1 month, 3-6 months,
then yearly
Critical Limb Ischemia
• Limb threatening ischemia seen in 1-2% of
patients with PAD >50 years old Circulation.
2006;113(11):e463.
• At 1 year, 25% of these patients are dead
and 25% have had an amputation
• Most of these patients have significant
comorbidities
10/10/2015
14
Chronic Limb Ischemia
• Amputation portends an especially poor
prognosis
• 40-50% 2 year mortality (Risk factors as
well as co-existent vascular disease in
cardiac/cerebral beds)
• Also the after effects of amputation:
depression, decreased mobility,
institutionalization
Get these patients a cardiovascular
evaluation!
• 40-60% of these patients don’t have a
vascular referral
• Amputations are preventable
• Even if not preventable, they are healable.
BASIL trial: endovascular therapy vs.
open revascularization for critical limb
ischemia
Survival benefit seen for
surgery at 2 years.
For patients expected to
have <2 year life expectancy,
endovascular approach might
be better than open
revascularization
10/10/2015
15
Treat inflow first
Inflow disease (aorta, iliac) has 80%
success rates
SFA-Popliteal disease has 30-70%
success rates
Tibioperoneal disease has 30-75%
success rates
Wound healing vs. long term
success
Angiosome guided therapy
• Below the knee
interventions have
lower technical
success rates, but
inline flow to an
ulcer will improve
healing
10/10/2015
16
Other LE PAD conditions to
know about• Buerger’s disease: inflammatory vasculitis of
small and medium sized arteries, veins and
sometimes nerves. Strongly associated with
tobacco use, and cannot be treated without
tobacco cessation.
• Peripheral Aneurysm: Atherosclerosis mediated
weakness in the arterial wall causes dilation.
Associated with pain, mass effect on nearby
structures (e.g. veins) and embolic disease.
Treatment is primarily surgical.
Renal Artery Stenosis
www.radblazer.com
When to Consider Renal Artery
Stenosis• Unstable cardiac syndromes
– Recurrent flash pulmonary edema
– Refractory heart failure
– Refractory unstable angina
• HTN (RAS is the second most common cause)
– Accelerated hypertension
– Resistant hypertension (unable to controle with 3 or more
agents)
– Onset at a young age (<30 years old)
• Renal Dysfunction (especially if worsened by ACE
inhibitor or ARB)
• Asymmetric atrophic kidney
10/10/2015
17
Pathophysiology of
Renovascular Hypertension• With unilateral renal artery stenosis, decreased
blood flow to the affected kidney is sensed as
decreased plasma volume
• The kidney then produces more renin, which
makes more angiotensin II
• Angiotensin II is a direct vasconstrictor
• Angiotensin II also increases aldosterone
secretion: sodium and fluid are retained
• The healthy kidney can at least partly
compensate for this process
Bilateral Renal Artery Stenosis
• Decreased blood flow to both kidneys
results in increased renin->angiotensin->
aldosterone
• Volume expansion occurs, somewhat
compensating for the stenosis
• If ACE-inhibitors or angiotensin receptor
blockers are administered, volume
expansion is blocked and the kidneys see
MUCH less flowacute renal insufficiency
How to Make the Diagnosis?
• Duplex US
• CT Angiography
• MR Angiography
• Catheter angiography is recommended if
other tests are inconclusive
10/10/2015
18
Renal Artery Interventions
• 90% of disease is atherosclerotic
• Usually ostial or proximal disease;
progression to complete occlusion over
time is common (10% of ESRD is caused
by RAS)
• Technical Success Rate: 95%
• Clinical Response rates much lower
– Patient selection
– Is RAS the cause of hypertension or renal
insufficiency?
Renal Artery Intervention:
Procedural Considerations• Femoral Access is commonly used, but can also use radial or
brachial access (require longer catheters)
• 6F sheath (2 mm)
• Renal Artery is engaged with a guide catheter
• 0.014” wire is used to cross the lesion
• Angioplasty is performed to facilitate stent delivery
– If patient has flank pain, the angioplasty is too aggressive
• A stent is delivered to cover the lesion and deployed
– Normal size of renal artery is 5-6 mm
– For ostial/proximal disease, the stent should extent 1-2 mm into the
aorta to allow full strength of stent to cover atherosclerosis
• Some evidence suggests that drug eluting stents have better long
term outcomes than bare metal stents, especially for smaller vessels
(up to 30% restenosis rate for vessels <4 mm, appx. 10% for 5 and
6 mm vessels)
Sample Case (not mine)
Circulation: November 10, 2009 vol.
120 no. 19e157-e158
10/10/2015
19
Fibromuscular Dysplasia
• 10% of renal artery stenosis
• Commonly affects young
women; cause unknown
• Typically involves the mid or
distal portion of the renal
artery
• Rarely leads to vessel
occlusion or ischemic
nephropathy (but can lead to
hypertension)
• Responds well to balloon
angioplasty (if necessary)
Renal Artery Denervation
• The adventitia of the renal arteries has a
high concentration of sympathetic nerves
• Surgical denervation used to be a
treatment for resistant hypertension
• Catheter based radioablation might afford
similar results
Simplicity 2 Trial
• Renal Artery denervation vs. medical therapy:
sustained improvement in BP (2032 mmHg in
denervation patients)
10/10/2015
20
Simplicity 3 Trial
• 535 patients 18-80 years old, randomized
2:1 fashion to denervation vs. sham
procedure (renal angiography)
• Patients had to have 3 office SBP
measurements >160 mmHg
• Patients had to be taking maximally
tolerated doses of at least 3 different
classes of blood pressure drugs, including
diuretic
Bhatt DL et al. N Engl J Med 2014;370:1393-1401.
Home BP Monitoring
Bhatt DL et al. N Engl J Med 2014;370:1393-1401.
Ambulatory BP monitoring
10/10/2015
21
The Future of Renal
Denervation
• Boston Scientific is currently conducting a 100 patient trial with their own
catheter, which they claim has better technology (circumferential rather than
point ablation)
• May have a role in certain patients with sympathetic overload (how to
diagnose?)
• Hypertension, in large part, is a disease controllable with medications and
lifestyle
• ADHERENCE to medications may be the key
• Diuretics should be used in all patients with “resistant” hypertension
• If the diuretic isn’t making your patient urinate, then increase the dose
Chronic Mesenteric Ischemia
• Intestines are supplied
by 3 main arteries:
celiac, superior
mesenteric and inferior
mesenteric
• Robust collateral
formation can occur,
from these branches as
well as branches of
hepatic, renal or
mammary arteries
Chronic Mesenteric Ischemia
• Suspect in postprandial abdominal pain,
especially in patients with atherosclerosis
in other beds
• Patients will often avoid eating and lose
weight
– A lot of patients will have undergone a
malignancy workup
• Anatomically, generally need to have 2 our
of 3 vessels with significant disease
• Can be treated endovascularly
10/10/2015
22
Carotid Artery Stenosis
The Carotid artery branches off the aorta (left)
and off the innominate (right), and divides into
the internal (supplies brain) and external
(supplies face and eye) branches
Stenosis can be anywhere, but commonly in
the bulb or at a branch point.
Unlike coronary disease or lower extremity
disease, cerebrovascular disease often
seems to be an embolic phenomenon rather
than a fixed perfusion deficit phenomenon.
Crumbly plaques are bad!
Symptomatic Carotid stenosis
• Symptomatic defined as TIA or stroke in
the last 6 months
– Amaurosis Fugax should also be a warning
sign
• >70% stenosis: 26% stroke risk over 2.5
years
• 50-69% stenosis: 18% stroke risk over 5
years
Asymptomatic Carotid Stenosis
• Stroke risk is relatively low
• Risk of ipsilateral stroke 3.2%/year for
asymptomatic stenosis 60-99% (North
American Symptomatic Carotid
Endarterectomy Trial, NEJM 2000)
– This was in an era before high prevalence
statin/antiplatelet use
10/10/2015
23
Should I listen for a bruit?
• Detection of a carotid bruit has less than
20% correlation with carotid stenosis
(Stroke 1998; 29:750-753)
• Referred murmurs commonly mistaken for
bruits
• Not all atherosclerosis results in
auscultatable bruit, especially if severely
stenosis
• However, I still do it
How to treat medically?
• Aspirin or Plavix
• High dose statin (Atorvastatin 40-80mg,
Rosuvastatin 20-40 mg)
• Aggressive BP control
• Diabetes control
• Lifestyle changes
• If stenosis >60%, regular screening to
monitor for progression
When to intervene?
• Trials of intervention were done when medical
therapy meant aspirin alone
• If patient has >5 year life expectancy and has
asymptomatic stenosis >70%, worth discussing.
• If patient has >5 year life expectancy and
symptomatic carotid stenosis >50%, worth
discussing
• If patient has >5 year life expectancy and has
symptomatic carotid stenosis >70%, benefits
usually outweigh the risks
10/10/2015
24
Carotid Endarterectomy vs.
Stenting• Carotid endarterectomy carries a higher
risk of MI (2.3% vs. 1.1%)
• Carotid stenting carries a higher risk of
stroke (4.1% vs 2.3%)
• Combined endpoint and quality of life
measures were no different at 1 year
• Medicare doesn’t pay for carotid artery
stenting outside of clinical trials unless
endarterectomy is contraindicated.
Take Home Lessons
• PAD is a very common entity
• Guidelines recommend screening for PAD
in any patient over 65, and in patients >50
with tobacco history or diabetes
• Patients with abnormal ABI should get
aggressive lifestyle and medical therapy to
prevent stroke, heart attack and death
• If amputation crosses your mind, the
question of whether revascularization can
help should also cross your mind
Take Home Lessons
• Consider Renal Artery Stenosis with
unstable cardiac sydromes, accelerated
HTN, or unexplained renal insufficiency
• Treat resistant hypertension with drugs
and counselling for adherence/lifestyle.
• Adequately dosed diuretics are the key
10/10/2015
25
Take Home Lessons
• Asymptomatic carotid artery stenosis has
a low to moderate risk of stroke with
current therapy. Consider endarterectomy
if stenosis >70%.
• Symptomatic carotid artery stenosis had a
high risk of stroke depending on plaque
burden, and endarterectomy is the
treatment of choice.
PAD physicians in Central
Oregon• You can contact me at
• My office phone is (541) 388-4333
• My personal cell phone is (734) 883-3004
• Feel free to call me even if you just want to run a
patient by me
• My partner, Allen Rafael, also seed PAD
patients. Central Oregon also has an excellent
interventional radiologist (Garret Schroeder) and
two excellent vascular surgeons (Wayne Nelson
and Jason Jundt)