Predicting hemorrhagic transformation in posterior circulation stroke patients not treated with reperfusion therapies.

Introduction: Posterior Circulation (PC) stroke represents one-fifth of all ischemic strokes, with peculiar physiological characteristics. Hemorrhagic Transformation (HT) is a dreaded complication among stroke patients. Many predictive scores of this complication have been proposed, but none is designed specifically for PC stroke patients - therefore, patients who are not eligible for reperfusion therapies (RT) represent about 80% of hospitalized cases. We propose a scoring system to assess the HT risk in PC stroke patients not submitted to RT.

Methods: We retrospectively evaluated data of patients diagnosed with PC stroke not treated with RT from 5 Comprehensive Stroke Centers (four in Brazil, 1 in the US) from 2015 to 2018. All patients underwent CT scan or MRI at admission and a follow-up neuroimaging within seven days. Independent variables identified in a logistic regression analysis were used to produce a predictive grading score.

Results: We included 952 patients in the final analysis. The overall incidence of HT was 8.7%. Male gender (1 point), NIH Stroke Scale at admission ≥ 5 points (1), blood glucose at admission ≥ 160 mg/dL (1), and cardioembolism (2) were independently associated with HT. The AUC of the grading score (0 to 5 points) was 0.713 (95% CI 0.65-0.78). Subjects with a score ≥ 3 points had an OR of 4.8 (95% CI 2.9-7.9, p < 0.001) for HT.

Conclusions: Our score has good accuracy in identifying patients at higher risk of HT. This score may be useful for evaluating secondary prevention and stratifying patients in the context of even clinical trials.