This study found that compared with the control group, a higher proportion of patients in the low-dose statin group had improved NIHSS scores at 7 days after admission; a higher proportion of patients also had favourable functional outcomes at 90 days after onset. In the statin group, a lower proportion of patients had cerebral haemorrhage and gastrointestinal haemorrhage during hospitalization, and a lower proportion died within 2 years of onset. The use of low-dose statins was associated with NIHSS score improvement at 7 days after admission and good functional outcome at 90 days after onset but not with cerebral haemorrhage and gastrointestinal haemorrhage during hospitalization. Moreover, low-dose statin use was associated with fewer deaths within 2 years of onset. Subgroup analysis showed that the correlation between statins and outcome events was statistically significant in the noncardiogenic stroke subgroup but not in the cardiogenic stroke subgroup; the correlation between statins and outcome events was statistically significant in the complete recanalization subgroup but not in the incomplete recanalization subgroup. Overall, the location of the thrombus and bridging therapy had no significant effect on the correlation between low-dose statin use and outcome events.
Statin use was related to an improved short-term NIHSS score in this study, and the effect was significant in most subgroups. These results are consistent with study involving ischaemic stroke patients with thrombolysis7,11 and with other studies of ischaemic stroke populations12. The LDL value in the statin group after admission was opposite to that before admission, lower than that in the control group, and the proportion of patients with an LDL level reaching the guideline standard was also higher than that in the control group. According to analysis of whether the LDL level reached the guideline standard, it was found that 7 days after admission, more patients of statins group met the standard. And these patients which their LDL level reached the guideline standard had better prognosis than other patients, but the difference was not statistically significant.
Statin use was also related to a long-term FFO. The statin group had a higher FFO rate than the control group, and the effect was also significant in most subgroups. These results are consistent with those of other studies reporting that statins affect FFOs at 3 months in all acute ischaemic stroke patients13.
The statin group had lower rates of ICH or gastrointestinal haemorrhage than the other groups. In univariate logistic regression analysis, the use of statins, antiplatelet drugs and anticoagulants was inversely related to the rate of ICH; the use of statins and antiplatelet drugs was inversely related to the rate of gastrointestinal haemorrhage. However, the effect was not significant in most subgroups, especially for gastrointestinal haemorrhage. This result suggests weak statistical power for this relationship. Nevertheless, statins might decrease the rate of gastrointestinal haemorrhage, as one study showed that statins can decrease the gastrointestinal haemorrhage rate in myocardial infarction patients14. Regardless, additional studies are needed to draw a conclusion regarding the fewer gastrointestinal haemorrhage events in our study. Overall, the results suggest that statins do not increase the risk of haemorrhage events in patients with intra-arterial thrombectomy.
The statin group had a lower death rate within 2 years than the control group; indeed, statin use was significantly related to decreased death rates within 2 years, and the effect was significant in most subgroups. Statins have a similar effect on mortality in ischaemic stroke patients after stenting15.During the whole follow-up period, the incidence of death in the statin group was significantly lower than that in the control group.
Our study had several limitations. First, this was an observational cohort study, and only correlation results were obtained. Second, we did not compare the specific doses of statins in our study because high-intensity statins are rarely used in Asian clinical practice; thus, it is difficult to obtain relevant data. Accordingly, the correlation between high-intensity statins and prognosis of patients with thrombectomy needs further investigation. Third, the study included patients with thrombectomy and bridging. We conducted subgroup analysis according to different treatment methods, and bridging treatment did not change the correlation between statins and outcomes and prognosis, which is also similar to the results of the latest study17.
In conclusion, the use of low-dose statin was associated with NIHSS score improvement at 7 days after admission and favourable functional outcomes at 90 days in patients with acute ischaemic stroke undergoing intra-arterial thrombectomy. The use of low-dose statins was not associated with cerebral haemorrhage or gastrointestinal haemorrhage during hospitalization. Low-dose statins were associated with fewer deaths within 2 years after onset. The beneficial effect of statins was more significant in patients with noncardiogenic stroke and in those with complete recanalization after thrombectomy.