Abstract Body: Background:
Lipoprotein(a) (lp(a)) concentrations is an independent risk factor of atherosclerotic cardiovascular disease (ASCVD). The association between lp(a) and prognosis of ischemic stroke patients is uncertain.
Hypothesis:
The study is aimed to investigate the shape and the association of the risk of short-term and long-term stroke recurrence across the distribution of lp(a) concentrations, and explore whether combining ASCVD risk has an influence on the association.
Method:
Patients with acute ischemic stroke within 7 days in the Third China National Stroke Registry (CNSR-III) having lp(a) measurements were included in the study. The outcomes were stroke recurrence within one year and two years. ASCVD risk included diabetes mellitus, stroke history and early onset. Based on ASCVD risk and lp(a) concentrations, there were four groups: lp(a)<30 mg/dL, lp(a) 30-70 mg/dL without ASCVD risk, lp(a) 30-70 mg/dL with ASCVD risk, and lp(a) >70 mg/dL without ASCVD risk. To display the shape of the relationship between lp(a) and stroke recurrence within two years, lp(a) concentrations were modeled using natural cubic splines with median concentration serving as the reference adjusted by confounders. And the association was assessed using Cox proportional hazards models and Kaplan-Meier curves.
Result:
Among 9952 included patients with the mean age of 63 years and 69% of male, the median lp(a) concentrations was 18.06 (inter-quartile range, 8.85-35.66) mg/dL. The relationship between lipoprotein(a) and stroke recurrence appeared linear across the distribution. Compared to patients with lp(a)<50 mg/dL, lp(a)>=50 mg/dL was associated with a higher risk of stroke recurrence (adjusted HR for one-year outcome:1.19, 95%CI: 1.01-1.41, p =0.04; adjusted HR for two-year outcome:1.21, 95%CI: 1.04-1.40, p =0.01). Compared to patients with lp(a)<30 mg/dL, lp(a) 30-70 mg/dL combined with ASCVD risk was associated with a higher risk of stroke recurrence (HR:1.21, 95%CI: 1.04-1.42, p =0.03), but no increased risk was found in patients with lp(a) >70 mg/dL without ASCVD risk (HR:0.90, 95%CI: 0.65-1.26, p =0.55).
Conclusion:
Lipoprotein(a) concentrations was associated with short-term and long-term prognosis of ischemic stroke, with a linear risk gradient across the distribution. Baseline ASCVD risk may influence the association between lp(a) and stroke recurrence.