Lipoprotein(a) and functional outcome of acute ischemic stroke when discordant with low-density lipoprotein cholesterol

Abstract

Background: Several studies have indicated that residual cardiovascular risk might be associated with elevated lipoprotein(a) [Lp(a)] even in the setting of controlled low-density lipoprotein cholesterol (LDL-C). We aimed to prospectively examine the association between Lp(a) and unfavorable functional outcome among patients with acute ischemic stroke when Lp(a) and LDL-C were discordant.

Methods: Based on samples from the Infectious Factors, Inflammatory Markers and Prognosis of Acute Ischemic Stroke study, 973 patients with baseline plasma Lp(a) levels were included. The primary outcome was the composite outcome of death or major disability (modified Rankin Scale score of 3-6) at 6 months. Logistic regression models were used to estimate the risk for the primary outcome. Discordance analyses were performed, using difference in percentile units (>10 units), to detect the relative risk when Lp(a) and LDL-C were discordant.

Results: In total, 201 (20.7%) participants experienced major disability or death at 6 months. The multivariable-adjusted odds ratio (OR) for the highest quartile was 1.88 [95% confidence interval (CI): 1.16-3.04] compared with the lowest quartile. Each 1-SD higher log-Lp(a) was associated with a 23% increased risk (95% CI: 2%-47%) for the primary outcome. Compared with the concordant group, the high Lp(a)/low LDL-C discordant group was associated with increased risk for the primary outcome (adjusted OR: 1.59, 95% CI: 1.01-2.52).

Conclusions: Elevated plasma Lp(a) levels were associated with increased risk of major disability and death at 6 months. Discordantly high Lp(a)/low LDL-C was associated with an unfavorable functional outcome, supporting the predictive potential of plasma Lp(a) after ischemic stroke, especially when discordant with LDL-C. Key messages What is already known on this topic Previous studies have indicated that a positive association between increased lipoprotein(a) [Lp(a)] and cardiovascular disease risk remained even in patients who achieved controlled low-density lipoprotein cholesterol (LDL-C) levels. The findings of studies exploring the association between Lp(a) and unfavorable clinical outcomes of stroke were inconsistent, and whether Lp(a) can predict the risk of unfavorable functional outcome in stroke patients when Lp(a) and LDL-C levels are discordant remains unknown. What this study adds Elevated plasma Lp(a) levels were associated with increased risk of major disability and death at 6 months beyond LDL-C levels in acute ischemic stroke patients. How this study might affect research, practice, or policy The combination of LDL-C-lowering therapies and Lp(a)-lowering therapies may have better clinical efficacy for patients with ischemic stroke, and it is of great clinical interest to further explore this possibility in dedicated randomized trials.

Keywords: discordance analysis; ischemic stroke; lipoprotein(a); low-density lipoprotein cholesterol.