Plasma free fatty acids (FFAs) are related to lipid metabolism, and elevated levels of FFA have been associated with risk factors for atherosclerosis, such as abdominal obesity, arterial hypertension, and insulin resistance. The potential link between FFAs and ischemic stroke has been previously suggested, but no causal relationship has been established. A new study set out to investigate whether elevated FFAs constitute a risk factor for recurrent events in patients with cardioembolic stroke (Choi JY, et al. Neurology. 2014;82:1142-1148).
Using a hospital-based stroke registry in Korea, the investigators recruited patients between January 2008 and May 2010. The patients were enrolled in the study within 7 days of the onset of an acute ischemic stroke. Of the 864 patients with acute ischemic stroke who met the study inclusion criteria, 20 died during the initial hospitalization, 79 did not have baseline FFA level measurements (which disqualified them for the study), and 96 were lost to follow-up. A total of 669 patients were included in the study analysis.
Of the 669 patients, 429 were male, and the average age was 65.13 years. The patients were divided into 2 groups—those with noncardioembolic stroke (N = 564), who served as the control group, and patients with cardiometabolic stroke (N = 105). Of those with cardioembolic stroke, 79 patients had atrial fibrillation, 13 had patent foramen ovale or atrial septal defects, 10 had valvular heart disease, 9 had acute or recent myocardial infarction, and 1 had congestive heart failure.
The results showed that plasma FFA concentration was approximately 1.5-fold higher in patients with cardioembolic stroke than in those with ischemic stroke unrelated to cardioembolic disease (hazard ratio [HR], 2.1; 95% confidence interval [CI], 1.4-3; P <.001). During the 25.4-month follow-up period, 56 (8.4%) of all the patients had recurrent stroke, but the recurrence rate was not significantly different between the 2 groups—10.5% among patients with cardioembolic stroke and 8% in those with noncardioembolic stroke (P = .396).
However, a significant difference between the 2 groups was found in the association between stroke recurrence and plasma FFA concentration: in the patients with cardioembolic stroke, an elevated baseline FFA concentration was independently linked to stroke recurrence (HR, 2.7; CI, 1-6.9). By contrast, no such association was found in the patients with noncardioembolic stroke.
These results indicate that an elevated FFA level is a marker for stroke in patients with cardioembolism. Furthermore, an elevated FFA concentration may predict stroke recurrence in patients with stroke caused by cardioembolic disease. “Although FFA could be involved in CE [cardioembolic] stroke by several mechanisms, each mechanism may play some part in common pathophysiologic cascades,” the investigators concluded.