Asymptomatic Atherosclerosis Common in Lower-risk Individuals
NEW YORK (Reuters Health) – Nearly half of middle-aged adults with a low to intermediate risk of cardiovascular disease have at least one vessel with 50% or more stenosis when examined by whole-body magnetic resonance angiography (MRA), researchers have found.
“This is surprising given that the study was in asymptomatic individuals without diabetes who had low-intermediate risk of future cardiovascular events by standard risk factor assessment,” Dr. J. Graeme Houston of the University of Dundee, Scotland told Reuters Health by email.
Subclinical atherosclerosis is present for some time before clinical symptoms are noticed, and current techniques for early plaque detection are limited to one cardiovascular territory and might miss signs of atherosclerosis elsewhere.
In their study of 1,513 men and women aged 40 or older with no history of atherosclerotic disease, hypertension, diabetes, or statin treatment, Dr. Houston and colleagues used MRA of 31 vessel segments to quantify the burden and distribution of asymptomatic atherosclerosis.
Although 95% of vessels overall were normal, 49% of participants had at least one stenotic vessel (50% or more stenosis). And 27% of participants had stenosis in multiple arterial segments, the researchers report in Radiology, online May 1.
The standardized atheroma score (SAS), based on the percentage of analyzed segments with stenoses, correlated significantly with age, systolic blood pressure, total cholesterol, LDL cholesterol and the Adult Treatment Panel III cardiovascular risk score.
Linear multiple regression modeling identified age, heart rate, systolic blood pressure, Scottish Index of Multiple Deprivation decile, ex-smoking status and smoking status as independent predictors of SAS.
“The results confirm the feasibility for MRA as an imaging method for detecting early atherosclerotic disease in individuals at low-to-intermediate risk of cardiovascular events,” Dr. Houston said. “This approach could stratify individuals for the presence of disease burden which could inform further preventative therapy in the future.”
“It is important for us to determine if the finding of early stenotic arterial disease in such individuals confers a worse outcome in terms of future cardiovascular events at 5-year and 10-year follow-up,” he said. “That is our current research goal.”