Hyperlipidemia is associated with lower risk of poststroke mortality independent of statin use: A population-based study

Abstract

Background Although statin therapy is associated with reduced stroke and mortality risk, some studies report that higher lipid levels are associated with improved outcomes following ischemic stroke. Aims We examined the association of hyperlipidemia (HLD) combined with statin therapy on all-cause mortality in stroke patients. Methods All stroke patients in the Greater Cincinnati Northern Kentucky region of ∼1.3 million were identified using ICD-9 discharge codes in 2005 and 2010. Stroke patients with and without HLD were categorized based on their reported statin use at baseline or discharge into three groups: no-HLD/no-statins, HLD/no-statins, and HLD/on-statins. Cox proportional hazards model was used to estimate the risk of mortality at 30 days, 1 year, and 3 years poststroke. Results Overall, 77% (2953) of the 3813 ischemic stroke patients were diagnosed with HLD and 72% ( n = 2123) of those patients were on statin medications. The mean age was 70.0 ± 14.6 years, 56% were women, and 21% were black. In adjusted analyses, the HLD/no-statins group showed 35% (adjusted hazard ratio (aHR) = 0.65, 95% CI: 0.46-0.92), 27% (aHR = 0.73, 95% CI: 0.59-0.90), and 17% (aHR = 0.83, 95% CI: 0.70-0.97) reduced risk of mortality at 30 days, 1 year, and 3 years, respectively, poststroke, compared with no-HLD/no-statins group. The HLD/on-statins group showed an additional 17% significant survival benefit at 3 years poststroke compared with HLD/no-statins group. Conclusions A diagnosis of HLD in ischemic stroke patients is associated with reduced short- and long-term mortality, irrespective of statin use. Statin therapy is associated with significant, additional long-term survival benefit.

Keywords: Cerebral infarction; LDL; cholesterol; obesity; outcomes; survival.

Figure 1

Survival probability of ischemic stroke patients over time by HLD statin use status—multivariable analysis.