Carotid: Stroke Prevention

A recent page one Wall Street Journal article highlighted the nationwide underutilization of carotid duplex scanning and ankle-brachial index measurements for patients at risk for carotid and peripheral vascular disease. The well recognized association between peripheral vascular disease with subsequent neurologic or cardiac disability and mortality were graphically depicted.

In a September 24, 2004 article titled “Two Simple Tests Can Prevent Stroke, But Few Get Them” the authors featured several previously active and fully functional people who are “among a vast fraternity resulting from a great failure of modern American medical care: all suffered massive strokes when seemingly in good health”.

“Stroke is the third largest cause of death after heart attacks and cancer. Stroke is the leading U.S. cause of disability. Approximately 700,000 people experienced a stroke in 2002 and more than 1.1 million are impaired, many requiring nursing home care. The estimated cost of stroke is $53.6 billion this year alone”. One commentator estimated that roughly one-half of all stroke related deaths and permanent disability could be prevented with carotid ultrasound screening.

ABI’s are a significant marker for systemic vascular disease including coronary stenosis. An ABI score of 0.6 or less indicates a worse prognosis than from any other disease, even cancer. An ABI of 0.78 portends an approximately 30% five-year risk of heart attack, stroke, and vascular death. In a recent study from Minneapolis, patients over age 50 were screened if they had a history of diabetes or smoking. Peripheral arterial disease was found in 29%, the majority of whom were asymptomatic. The importance of obtaining ultrasound studies in a vascular lab with experienced ultrasound technicians was emphasized.

Who should be screened? Many vascular experts say everyone over age 60 should be considered for screening. Even for people under 60 these tests are imperative in the presence of risk factors such as diabetes, elevated lipids, a family history of stroke, obesity with a BMI of more than 30, abdominal obesity, and an elevated fasting blood glucose. When people over 55 years were screened, 10% had an abnormal ABI and 7% had a carotid stenosis measuring more than 50%. These findings were enough to warrant placing these patients on risk factor modifying medications such as aspirin, statins, ACE inhibitors, or Plavix. Surgical treatment of significant carotid stenosis decreased the stroke and death rate by 50% compared to medically treated patients.  

Clearly the need for screening for these “silent” diseases is great. The disability and death produced by untreated carotid and peripheral vascular disease is an immense burden for patients and their families. Careful attention to risk factor modification, appropriate drug therapies as well as the use of interventional modalities to treat these diseases will significantly impact the overall health and these patients and their families.

Such at-risk patients can be screened in our vascular laboratory (VUE LAB - Vascular Ultrasound Evaluation).