Low density lipoprotein cholesterol values and outcome of stroke patients: influence of previous aspirin therapy

Background: The link between low-density lipoprotein cholesterol (LDL-C) and stroke risk remains controversial and few studies have evaluated the effect of LDL-C after stroke survival. Aims: We assessed the hypothesis proposing the effect of LDL-C on the outcome of stroke patients under the influence of previous Aspirin Therapy. Methods: Associations between LDL-C and outcomes. The effect of LDL cholesterol on stoke outcome was evaluated using Kaplan-Meier methodology, log-rank test, Cox proportional hazard models and Bootstrap Analysis. Results: In a cohort of 342 cases, we observed that among stroke patients with no record of previous aspirin therapy LDL-C levels within recommended range (nLDL-C) are associated to a poor overall survival on (p < 0.001, log-rank test) leading to a 4-fold increased mortality risk in both timeframes of 12 (HR 4.45, 95% CI 1.55-12.71; p = 0.004) or 24 months (HR 4.13, 95%CI 1.62-10.50;p = 0.003) after the first event of stroke. Moreover, modelling the risk of a second event after the first stroke in the timeframe of 24 months demonstrated a predictive capacity for nLDL-C plasmatic levels (HR 3.94, 95%CI 1.55-10.05; p = 0.004) confirmed by Bootstrap analysis (p = 0.003; 1000 replications). In a further step, the inclusion of LDL-C in simulating models equations to predict the risk of a second event in the timeframe of 12 months increased nearly 20% the predictive ability (c-index from 0.763 to 0.956). Conclusion: A worse outcome was seen in stroke patients with normal levels of LDLC, but this finding was restricted to patients not under previous aspirin therapy.