Aspirin resistance and blood biomarkers in predicting ischemic stroke recurrence: An exploratory study

Recurrent strokes cause greater complications and worse outcomes by adding to the existing neurological deficit. There is the paucity of data on serum markers of inflammation as predictors of recurrent stroke. This study was planned to analyze the clinico-etiological profile of recurrent noncardioembolic ischemic stroke, estimate aspirin resistance among regular aspirin users and evaluate blood biomarkers high-sensitivity C-reactive protein (hsCRP), Tumor necrosis factor-alpha (TNF-α), Lipoprotein-associated phospholipase A₂ (Lp-PLA2) as probable predictors of stroke recurrence.

Patients of recurrent noncardioembolic ischemic stroke fulfilling the inclusion criteria were enrolled. Detailed history, clinical examination, and investigations were obtained as per protocol. Aspirin resistance was determined by light transmission aggregometry. Serum hsCRP, TNF-α, and Lp-PLA2 levels were estimated.

This study included 34 males and 16 females. Majority of the patients were > 60 years (n = 30, 60%). Thirty (60%) cases had a repeat stroke after 1 year of primary event. Thirty-nine (78%) study participants had hypertension, while 15 (30%) had diabetes. Middle cerebral artery (n = 40, 80%) was the most common vascular territory. Thirty-one (62%) cases belonged to TOAST subtype 1 (large artery atherosclerosis). Seventy two percent cases were prescribed aspirin after index stroke, but only 36% were compliant. Median (range) hsCRP level was 7.5 (0.3-155) mg/L with 72% of patients having high hsCRP level (>3 mg/L). Median (range) serum PLA2 level was 11.98 (3.31-87.24) ng/ml in patients and 6.96 (0.15-61.42) ng/ml in controls (P = 0.029). Median (range) serum TNF-α level in patients was significantly higher than controls (68.22 [1.3-287] pg/ml versus 0.098 [0.002-36.31] pg/ml, P < 0.001). Aspirin resistance was found in 41.7% patients while 16.7% were semi-resistant. Mean % platelet aggregation was 34.75 ± 21.58 in patients and 64.75 ± 16.98 for controls (P < 0.001).

Majority of patients with recurrent stroke were elderly (>60 years), hypertensive, and non-compliant with aspirin. Aspirin resistance was an important factor in patients with antiplatelet compliance. Inflammatory biomarkers hsCRP, PLA2, and TNF-α were found to be significantly elevated in patients compared to controls.