LDL-cholesterol levels and the risk of ischemic stroke in patients with non-valvular atrial fibrillation treated with new oral anticoagulants

Background: Low-density lipoprotein cholesterol (LDL-C) has been demonstrated as an independent risk factor of ischemic stroke. However, the association of LDL-C with ischemic stroke in patients with non-valvular atrial fibrillation (AF), especially in the new oral anticoagulants (NOACs) era, remains uncertain. Our objective was to evaluate the association between LDL-C and ischemic stroke in patients with AF.

Methods: The study was based on the Clalit Health Services database. Included were patients with non-valvular AF treated with NOACs. Patients were stratified into 3 groups according to the CHA₂DS₂-VASc score (1-2, 3-5, 6≤). Each CHA₂DS₂-VASc score group was further divided into 4 groups according to LDL-C levels (<70, 70-99, 100-130, 130<). The primary endpoint was the occurrence of ischemic stroke.

Results: Included in the study were 22,132 patients with a mean follow-up of 2.9±1.6 years. High CHA₂DS₂-VASc score was associated with increased risk of stroke. However, higher LDL-C levels within each CHA₂DS₂-VASc score group were not associated with increased stroke risk. For patients with low CHA₂DS₂-VASc score, stroke risk was 3.4%. 4.1%, 3.8% and 3.5% (for patients with LDL-C <70, 70-99, 100-130, 130<, respectively, p=NS). In the intermediate CHA₂DS₂-VASc score group stroke risk was 5.1%. 6.1%, 5.4% and 5.6% (for patients with LDL-C <70, 70-99, 100-130, 130<, respectively p=NS). For the high CHA₂DS₂-VASc score group, stroke risk was 14% 12.5%, 14.2% and 14.1% (for patients with LDL-C <70, 70-99, 100-130, 130<, respectively, p=NS)

Conclusions: Among patients with non-valvular AF treated with NOACs, higher LDL-C levels are not associated with increased risk of ischemic stroke regardless to the CHA₂DS₂-VASc score.