Cardiac Associates, P.C.

• What is peripheral arterial disease (PAD)?
• PAD is blockages of arteries other than the arteries of the heart.
• Generally PAD refers to blockages of:
• carotid arteries (carry blood through the neck to the brain)
• arm (subclavian) arteries
• kidney (renal) arteries
• leg arteries (i.e. iliac, femoral, or below knee)
• How much of a problem is PAD?
• PAD is widely prevalent and largely underdiagnosed. 20% of Americans over 65 years old have PAD!
• Only 25% of PAD patients are receiving treatment!
• PAD leads to significant morbidity & mortality, which, if diagnosed earlier, can hopefully be prevented
• Who is at risk for PAD?
• Diabetics and smokers are the 2 strongest risk factors for PAD
• Advanced age is also a risk factor for PAD

Types of Peripheral Arterial Disease

• Carotid Artery Disease
• Carotid arteries carry blood to the front and middle part of the brain
• Patients with coronary artery disease are at risk for carotid disease
• 90% of people with significant carotid artery disease have no symptoms
• Symptoms of carotid disease are those of transient ischemic attack or stroke
• Carotid stenosis is generally diagnosed by carotid ultrasound (a noninvasive test)
• The tighter the blockage in the carotid artery, the higher the risk for strok
• Medical therapy (diet, exercise, avoiding tobacco and BP control) is critical
• With severe blockages, carotid stenting or surgery (endarterectomy) may be recommended
• Vertebrobasilar artery disease
• Left and Right vertebrobasilar arteries come together and become the basilar artery and provide blood to the back part of the brain
• Blockage in the vertebral arteries or the basilar artery can compromise blood flow to the brain, causing symptoms such as dizziness
• Vertebrobasilar disease may be diagnosed by ultrasound
• Subclavian artery stenosis
• Subclavian arteries (left and right) carry blood to the respective arms. An important branch of the subclavian artery is the vertebral artery.
• Symptoms of subclavian artery blockage include:
• arm weakness or fatigue on the affected side
• dizziness (an entity known as subclavian steal syndrom). With subclavian steal, blockage in the beginning portion of the subclavian artery results in decreased flow to the arm beyond the blockage. Thus, to compensate, the blood in the vertebral artery then flows backwards (i.e. away from the brain) in order to provide adequate blood flow to the affected arm. Consequently the brain receives decreased blood flow from the affected vertebral artery and dizziness can result. This blood flow backwards in the vertebral artery may be seen on ultrasound.
• In patients with prior heart bypass surgery, the internal mammary artery (IMA) is often one of the bypass grafts used. The IMA is another branch of the subclavian artery. Blockage in subclavian artery can thus compromise blood flow to the bypass graft (IMA) and result in chest discomfort, shortness of breath or fatigue.
• Ultrasound may diagnose subclavian artery blockages
• Symtomatic subclavian artery blockages can be treated with stents
• Renal artery stenosis
• Renal artery stenosis is blockage of the kidney arteries
• What suggests renal artery stenosis?
• Premature onset ofhypertension (HTN) or abrupt worsening of previously well-controlled HTN
• Difficult to control HTN on multiple medication
• Recurrent episodes of flash pulmonary edema (a medical term for severe, sudden shortness of breath due to water filling in the lungs)
• Renal failure thought secondary to renal artery stenosis
• Blockages in the renal arteries can be assessed by renal artery ultrasound or renal magnetic resonance angiography.
• Renal artery stenosis can be treated by stenting
• Lower extremity (leg) peripheral arterial disease
• Symptoms of blockages in the arteries to the legs include calf or thigh pain, aching or fatigue with walking. These symptoms are typically relieved with rest. This is known as "claudication."
• More severe manifestations of PAD include limb-threatening ischemia i.e. rest pain or non-healing foot/leg ulcerations
• Amputation may sometimes be needed if the leg/foot/toe can not be saved
• If lower extremity PAD is suspected, the ankle-brachial index (ABI) can be assessed.
• The dorslis pedis and the posterior tibial are the two pulses that are present in the feet
• Right leg ABI = (higher of the right dorsalis pedis or right posterior tibial systolic blood pressure/higher of right or left arm systolic blood pressure)
• Left leg ABI = (higher of left dorsalis pedis or left posterior tibial systolic blood pressure/ higher of right or left arm systolic blood pressure)
• ABI 0.9 to 1.3 is within normal limits
• ABI 0.7 to 0.9 is mild PAD
• ABI 0.4 to 0.7 is moderate PAD
• ABI <0.4 is severe PAD
• ABI (ankle-brachial index) <0.9 means one has PAD
• a diagnosis of PAD means one is at higher risk for cardiovascular problems, and thus medical management of cardiovascular risk factors should be intensified
• Arterial ultrasound can help assess the extent of blockage in the legs
• The above tests (ABI and arterial ultrasound) are typically done with the patient at rest. However, some patients may have a very good story for PAD yet their resting ABI may be > 0.9. These patients may still have PAD but may need exercise to bring out the abnormality in ABI. Thus, exercise ABI may be performed in such patients, or lower extremity angiogram may be performed for definitive diagnosis.
• Exercise is the main recommendation for lower extremity PAD.
• A medication, pletal (cilostazol), is sometimes used for leg symptoms, but in general, effectiveness of pletal is limited
• Patients with lower extremity PAD who continue to have significant leg symptoms despite risk factor modification, exercise and possibly pletal should be considered for lower extremity angiogram and possible balloon or stenting
• Bypass surgery of the legs is also a revascularization option

Any patient with established diagnosis of carotid, subclavian, renal or lower extremity PAD, should receive regular follow-up and noninvasive imaging.