Novel peripheral blood cell ratios: Effective 3-month post-mechanical thrombectomy prognostic biomarkers for acute ischemic stroke patients

Background Red blood cell distribution width to platelet ratio (RPR), Monocyte to high-density lipoprotein ratio (MHR), and Neutrophil to lymphocyte ratio (NLR) are novel inflammatory biomarkers in laboratory tests, which are associated with clinical outcomes in malignancy, cardiovascular and cerebrovascular diseases. This study aimed to determine their predictive value for the prognosis of acute ischemic stroke after mechanical thrombectomy (MT). Methods A total of 286 patients with acute ischemic stroke (AIS) admitted to a tertiary stroke center in China between January 2018 and February 2020 were treated by MT. Demographic characteristics, risk factors, clinical data, laboratory parameters, and clinical outcomes were recorded. The clinical outcome was disability or death at discharge or 90 days (defined as a modified Rankin Scale score of 3–6). The relationship between RPR, MHR, and NLR and functional outcomes was investigated by binary Logistic regression analysis, and further assessed by receiver operating characteristic curve (ROC). The Kaplan-Meier method was used to analyze the survival rate of prognosis factors. Results A total of 286 patients with AIS underwent MT (median age, 70.00; Interquartile range [IQR], 63.00–77.00; 41.6% female). Patients with unfavorable outcome showed higher RPR, MHR, and NLR than those with favorable outcome (RPR, [8.63; IQR, 6.30–10.78] vs [6.17; IQR, 5.11–7.35], P < 0.001; MHR, [0.40; IQR, 0.31–0.53] vs [0.34; IQR, 0.27–0.47], P = 0.005; NLR, [5.28; IQR, 3.63–8.02] vs [3.44; IQR, 2.63–4.63], P < 0.001). In multivariate and ROC curve analysis, higher RPR (>8.565) (odds ratio [OR], 1.671; 95% confidence interval [CI], 1.127–2.479; P = 0.011) and higher MHR (>0.368) (OR, 9.374; 95% CI, 1.160–75.767; P = 0.036), higher NLR (>4.030) (OR, 1.957; 95% CI, 1.382–2.770; P < 0.001) were independently associated with unfavorable outcome. The combined predictive value of the three indexes was higher than that of a single index. Kaplan-Meier survival curve analysis showed that the 90-day survival rate (82.1% vs 66.2%) was significantly different between the low RPR group and the high RPR group (χ2 = 4.960, P = 0.026). Conclusion Higher RPR, MHR, and NLR might be independent risk factors for predicting 3-month poor prognosis in patients with AIS who underwent MT.