NEW ORLEANS—Testing for elevated levels of lipoprotein-associated phospholipase A2 (Lp-PLA2) in patients at moderate to high risk for cardiovascular events can identify those at the greatest risk for ischemic stroke, according to research presented by Mark J. Alberts, MD, and colleagues at the 2008 International Stroke Conference. They asserted that testing of Lp-PLA2 levels would allow for more accurate targeting of therapies for patients.
Stroke Risk Increased With Lp-PLA2 Activity
Dr. Alberts, a Professor of Neurology at Northwestern University and Director of the Stroke Program at Northwestern Memorial Hospital in Chicago, and his coinvestigators reviewed data from five large studies that examined the association between Lp-PLA2 and risk of ischemic stroke: the Atherosclerosis Risk in Communities (ARIC) study, the Rotterdam Study, the Northern Manhattan Study (NOMAS), the Women’s Health Initiative (WHI), and the Malmo Diet and Cancer Study. All of the studies assessed risk of first stroke, except for the NOMAS, which assessed risk of recurrent stroke.
In the Rotterdam Study, ARIC, and the Malmo Diet and Cancer Study, the relative risks for ischemic stroke per 1-SD increase in Lp-PLA2 were 1.24, 1.30, and 1.23, respectively. Hazard or odds ratios of ischemic stroke in the high versus low quintiles of Lp-PLA2 activity ranged between 1.55 (for healthy postmenopausal women not receiving hormone replacement therapy in the WHI) and 2.29 (for healthy subjects in the ARIC). Only postmenopausal women receiving hormone replacement therapy appeared to be at a decreased risk (odds ratio, 0.70).
Cholesterol Goals
Dr. Alberts and colleagues recommended testing of Lp-PLA2 levels among patients at moderate or high cardiovascular risk. If the results indicate increased Lp-PLA2 activity, then the patient’s LDL cholesterol goal should be adjusted accordingly. For example, the researchers advised that patients at moderate cardiovascular risk with normal Lp-PLA2 activity should have an LDL cholesterol goal of less than 130 mg/dL; however, those with Lp-PLA2 levels greater than 200 ng/mL have the same LDL cholesterol goal as those at high cardiovascular risk (
“New markers such as Lp-PLA2 have the ability to differentiate high-risk from low-risk patients before an event occurs,” concluded Dr. Alberts and colleagues. They suggested that intensified treatment of nonlipid risk factors and therapeutic lifestyle changes can help patients reach their LDL cholesterol goal and reduce the risk of vascular events.
—Jessica Dziedzic