3D imaging may predict stroke risk

This study examined whether identification of changes in plaque composition in the carotid may be related to subsequent vascular events in a high risk population.

The carotid arteries are the main suppliers of blood to the brain. Carotid atherosclerosis is the most common of carotid artery diseases. In this disease there is a slow progressive accumulation of plaque (fatty deposit on the inside of the arterial wall) in the carotid arteries, decreasing blood flow to the brain and increasing the risk of stroke.

Due to the danger of carotid disruption there is an urgent need for rapid, reliable, and cost-effective methods to monitor patients who are at high risk for adverse vascular events. Ultrasound is a relatively inexpensive and widely available imaging method enabling imaging measurements of the carotid artery wall (such as plaque burden). Ultrasound also provides a way to measure plaque texture. Plaque texture takes into account the composition of the plaque deposit, analysing fatty cores and intraplaque hemorrhage (blood vessels leaking within the plaque), both of which destabilize the plaque, and calcification, which stabilizes the plaque.

This study examined if changes in both parameters may predict future vascular events.

In this study 298 patients were enrolled. All patients had a history of risk factors such as high blood pressure, high values of lipids (fats) in the blood, diabetic or with a history of a vascular event. All patients suffered from carotid atherosclerosis. 3D ultrasound scans of both carotid arteries were performed on each patient at the beginning of the study and after 1 year. Researchers compared both scans for changes in plaque volume and texture.

The average follow-up was 3.1 years. Any report of stroke, transient ischemic attack (inadequate blood supply to an organ or area) or heart attack was recorded as a vascular event.  By the end of the study 27 patients experienced a vascular event.

Following analysis researchers concluded that both total plaque volume changes and texture changes were significant predictors for vascular events. Changes in plaque texture were associated with a 40% increased risk of vascular events while changes in plaque volume were associated with a 50% increased risk of vascular events. Combining changes in texture and total plaque volume provided the best predictor of vascular events.

This study concluded that changes in both plaque texture and volume (examined with 3D carotid ultrasound) in the carotid are strongly predictive of vascular events in a high risk population.

It should be noted that these results hold only for subjects with identified carotid atherosclerosis.