Abstract TP110: Apolipoprotein B as a Biomarker for Stroke Etiology and Atherosclerotic Risk

Despite achieving guideline-recommended LDL-C levels, 22.7% of patients experience major cardiovascular events, highlighting the need for sensitive biomarkers of atherosclerotic risk. Apolipoprotein B (ApoB), present in atherogenic lipoproteins including LDL, may better reflect atherogenic burden, particularly in patients with LDL discordance due to metabolic syndrome or hypertriglyceridemia. While ApoB measurement is included in several cardiology guidelines, its role in ischemic stroke remains underexplored. We hypothesized that ApoB levels correlate with LDL levels in ischemic stroke, are elevated in patients with atherosclerotic etiology, and reveal lipid-related risk in stroke despite LDL at goal. The study enrolled 56 patients with image-confirmed ischemic strokes. ApoB testing was added to the standard lipid panel. Clinical and demographic data, including comorbidities, lipid-lowering therapy, imaging, and stroke etiology was collected by chart review. LDL and ApoB were compared across stroke etiologies and target thresholds. Pearson correlation and t-tests were used for statistical analysis. ApoB and LDL showed moderate correlation (R = 0.659). The median levels across all patients were an ApoB of 85.9 mg/dL and LDL of 111 mg/dL. Average ApoB levels per stroke etiology were 97.55 mg/dl for small vessel, 87.25 mg/dl for cryptogenic, 84.42 mg/dl for large vessel, and 78.43 mg/dl for cardioembolic. Average LDL levels were 125.45 mg/dl for small vessel, 115.75 mg/dl for cryptogenic, 101.83 mg/dl for large vessel, and 108.48 mg/dl for cardioembolic. Of the 51 patients with complete ApoB testing, 31 exceeded the LDL target of <100 mg/dL in patients without prior ischemic stroke or <70 mg/dL in patients with prior ischemic stroke, and 16 exceeded ApoB targets of <80 mg/dL in patients with prior ischemic stroke or <90 mg/dL in patients without prior ischemic stroke (p = 0.0029). Discordance with elevated ApoB despite LDL at goal was uncommon (n=2), however the selected targets showed a higher sensitivity of LDL compared to ApoB, suggesting that more studies are needed to select target values for this emerging biomarker. Stroke subtype analysis yielded higher, non-significant median ApoB and LDL levels in small vessel compared to large vessel disease (ApoB p = 0.325, LDL p = 0.225). While preliminary findings suggest a trend toward elevated ApoB in small vessel disease, further enrollment is needed to investigate ApoB’s role in stroke prevention.