Low-to-moderate dose statins improve the functional outcome of acute ischemic stroke with conventional medication treatment

BACKGROUND: Low-to-moderate dose statins (LMDSs) are more commonly used among Asian acute ischemic stroke (AIS) patients in clinical practice. However, the correlation between the LMDS use and prognosis has not been evaluated in AIS patients with conventional medication treatment alone. This study aimed to investigate the influence of LMDS on the prognosis of AIS patients and how prognosis and potential prognostic factors interact with different statin doses. METHODS: This retrospective cohort study included AIS patients who were admitted within 7 days after symptom onset and received conventional medication treatment alone from November 2019 to November 2020 in the Neurology, Department of West China Hospital, Sichuan University. From a total of 782 initial patients, a final cohort of 327 patients was included in the study. These patients were divided into three groups based on statin doses: non-statin (48 patients), LMDS (152 patients), and high-dose statin (HDS) (127 patients). The follow-up period was 3 months after the onset of stroke and the primary outcome was defined as a modified Rankin scale (mRS) score of 0 to 2 at 3 months, secondary outcomes were hemorrhagic transformation (HT) and death within 3 months. Stratified analysis was also conducted to test the robustness of the relationship between the use of different statin doses and functional outcomes in various subgroups. RESULTS: Compared with non-statin therapy, both LMDS therapy and HDS therapy were associated with good functional outcomes [odds ratio (OR) =3.68, 95% confidence interval (CI): 1.13–12.01, P=0.0309; OR =3.45, 95% CI: 1.06–11.26, P=0.0402, respectively] and a lower risk of HT (OR =0.30, 95% CI: 0.11–0.86, P=0.0253; OR =0.36, 95% CI: 0.13–0.99, P=0.0488, respectively). However, there was no significant difference in all-cause death within 3 months among the three groups (OR =0.84, 95% CI: 0.29–2.46, P=0.7468; OR =0.76, 95% CI: 0.26–2.22, P=0.6104). Additionally, no significant differences were observed between LMDS therapy and HDS therapy regarding good functional outcomes at 3 months (OR =0.94, 95% CI: 0.50–1.77, P=0.8411) and the occurrence of HT (OR =1.19, 95% CI: 0.47–3.02, P=0.7093). The results of the relationship between different statin doses and 3-month good functional outcome were consistent after interaction tests. CONCLUSIONS: Our findings provide evidence for the benefit and safety of LMDS therapy in AIS patients with medication treatment alone. LMDS therapy is associated with favorable impacts on 3-month functional outcomes and a reduced risk of HT compared to non-statin therapy. There were no significant differences in achieving 3-month good functional outcome, the risk of HT or death within 3 months were observed between LMDS and HDS therapy in our study. Further studies with prospective design and larger sample sizes are necessary to validate our results.