The association between lipid profiles and the neurologic outcome in patients with out-of-hospital cardiac arrest

Abstract

Background

Lipid profiles are known to be a risk factor for development of cardiovascular disease. However, the relationship between lipid profiles and outcome in out-of-hospital cardiac arrest (OHCA) survivors remains unclear. We aimed to examine the association between lipid profiles and neurologic outcome in OHCA survivors.

Methods

This retrospective observational study included adult (≥18 years) OHCA survivors between January 2016 and December 2018. We measured patients’ lipid profiles after return of spontaneous circulation (ROSC) including total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglyceride. The primary outcome was neurologic outcome at hospital discharge. Good neurologic outcome was defined cerebral performance categories 1 and 2.

Results

A total of 182 patients were included. Of them, 57 (31.3%) were discharged with good neurologic outcomes. Median serum levels of total cholesterol (178.0 vs. 123.0 mg/dL), HDL (44.0 vs. 31.0 mg/dL), and LDL (104.0 vs. 75.0 mg/dL) were significantly higher in patients with good neurologic outcome. The area under the curves of total cholesterol, HDL, LDL, and triglyceride were 0.742 (95% confidence interval [CI], 0.672–0.803), 0.729 (95% CI, 0.658–0.792), 0.683 (95% CI, 0.610–0.750), and 0.572 (95% CI, 0.497–0.645), respectively. Total cholesterol (odds ratio [OR], 1.013; 95% CI, 1.000–1.025; p = 0.043) and HDL (OR, 1.071; 95% CI, 1.021–1.123; p = 0.005) levels were associated with good neurologic outcomes.

Conclusions

The levels of total cholesterol and HDL after ROSC were associated with good neurologic outcomes in patients with OHCA, without considering the effect of other lipid profiles simultaneously.

Introduction

The lipid profiles usually include total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides. The lipid profile is known as a risk factor for atherosclerotic disease such as acute coronary syndrome.¹ Since sudden cardiac death (SCD) accounts for one-half of all coronary heart disease-related deaths, several studies have reported on the association between lipid profile and risk of SCD.2, 3, 4 In a study including 139 out-of-hospital cardiac arrest (OHCA) patients, cholesterol, LDL, and non-HDL levels were lower in the SCD group than in the geographic control group.² Jouven et al. reported that that high cholesterol level is associated with incidence of SCD.³

The association between lipid profiles and various pathologic conditions has also been investigated in several studies.5, 6, 7, 8, 9 Interestingly, in contrast to “the lower, the better” cholesterol hypothesis that has been generally accepted by many health care professionals, low cholesterol level was associated with poor prognosis in cancer,⁵ sepsis,⁶ and ischemic stroke.⁷ Additionally, in large cohort population-based study, high cholesterol level was associated with reduced all-cause mortality.⁸ This may be a clue that cholesterol contributes positively to the healing or recovery from pathologic conditions, apart from the characteristics of atherogenicity and contribution of coronary artery disease development. However, the relationship between lipid level and outcomes in OHCA survivors have been investigated only in a few studies.⁹

We hypothesized that dyslipidemia is associated with neurologic outcomes in OHCA survivors. Hence, in the present study, we aimed to investigate the association between serum lipid profiles and neurologic outcome in OHCA survivors. Furthermore, we aimed to examine the prognostic performance of lipid profile for neurologic outcome.