LDL Cholesterol Predicts Ischemic Stroke in Atrial Fibrillation

Low-density lipoprotein cholesterol (LDL-C) may be an independent predictor of ischemic stroke in patients with atrial fibrillation (AF), according to results from a study conducted in Shanghai, China, and published in the American Journal of Cardiology.¹

Vascular disease has been identified as a risk factor for ischemic stroke in patients with AF, and it has been incorporated into the CHA₂DS₂-VASc (congestive heart failure, hypertension, age ≥75 [doubled], diabetes mellitus, stroke [doubled]-vascular disease, and sex category [female]) score as such.^2,3 Increased stroke risk has also been linked to carotid intima-media thickness and carotid plaque in patients with AF.⁴

 

Taken together, these findings suggest atherosclerosis is an important factor in predicting ischemic stroke risk in this patient group.

LDL “participates in the promotion, development, and progression of atherosclerosis through a pathway that involves endothelial cell dysfunction, lipoprotein oxidation, foam cell formation, and inflammatory responses,” the researchers wrote.⁵ “However, the role of [LDL-C] in predicting ischemic stroke in AF patients has not been explored.”

They examined this relationship in a sample of 424 patients with nonvalvular AF who presented to the emergency department with acute ischemic stroke. Patients with AF without ischemic stroke (n = 391) served as controls. None of the patients had received treatment with antithrombotic agents.

The findings revealed that LDL-C independently predicted ischemic stroke in patients with AF (adjusted odds ratio [OR], 2.004; 95% CI, 1.624-2.473; P <.001). The best LDL-C cutoff value to predict this outcome was 2.48 mmol/L, with 56.3% sensitivity and 66.3% specificity (area under the curve, 0.651; P <.001). Results of a subgroup analysis based on different CHA₂DS₂-VASc scores, which adjusted for the various components that comprise the score, showed that the predictive value of LDL-C remained significant in patients who had a CHA₂DS₂-VASc score of 5 or less, but not in those whose score was 6 or higher.

“In conclusion, LDL-C was an independent predictor of ischemic stroke, which could potentially refine stroke stratification in AF patients,” the researchers wrote.

“The addition of LDL-C information could provide incremental predictive value for risk of ischemic stroke, over the CHA₂DS₂-VASc risk score, which is solely based on clinical variables.”

To validate these findings, future research should include a prospective design and a larger sample.

References

1. Zhiyong Qi, Hua Chen, Zhichao Wen, et al. Relation of low-density lipoprotein cholesterol to ischemic stroke in patients with nonvalvular atrial fibrillation [published online January 25, 2017]. Am J Cardiol. doi: 10.1016/j.amjcard.2016.12.031
2. Anandasundaram B, Lane DA, Apostolakis S, Lip GY. The impact of atherosclerotic vascular disease in predicting a stroke, thromboembolism and mortality in atrial fibrillation patients: a systematic review. J Thromb Haemost. 2013;11(5):975-987. doi: 10.1111/jth.12177
3. Camm AJ, Lip GY, De Caterina R, et al; ESC Committee for Practice Guidelines (CPG). 2012 focused update of the ESC guidelines for the management of atrial fibrillation: an update of the 2010 ESC Guidelines for the management of atrial fibrillation. Developed with the special contribution of the European Heart Rhythm Association. Eur Heart J. 2012;33(21):2719-2747. doi: 10.1093/eurheartj/ehs253
4. Bekwelem W, Jensen PN, Norby FL, et al. Carotid atherosclerosis and stroke in atrial fibrillation: The Atherosclerosis Risk in Communities Study. Stroke. 2016;47(6):1643-1646. doi: 10.1161/STROKEAHA.116.013133
5. Berliner JA, Navab M, Fogelman AM, et al. Atherosclerosis: basic mechanisms. Oxidation, inflammation, and genetics. Circulation. 1995;91(9):2488-2496. doi: 10.1161/01.CIR.91.9.2488