Prehospital delay and thrombolysis rates in posterior circulation stroke: a multicenter Latin American study

We aimed to evaluate the delay to emergency arrival in adults with acute Posterior circulation ischemic strokes (PCS) and the likelihood of receiving intravenous thrombolysis compared to anterior circulation ischemic strokes (ACS) across six different hospitals in Latin America.

This multicenter study in Latin America hospitals including three hospitals in Peru (Cusco, Arequipa, and Lima City), one in Colombia (Bogotá), one in Chile (Valdivia), and one in Mexico City. We analyzed adult patients treated between 2018 and 2023 with a confirmed diagnosis of ischemic stroke (IS). We evaluated demographic characteristics, initial NIHSS score, onset-to-door time (ODT), rate of intravenous thrombolysis (IVT), and other stroke-related characteristics. Medians with interquartile ranges (IQR) were calculated. IVT (yes/no) was evaluated using Firth penalized logistic regression including stroke circulation, age, sex, admission NIHSS, ODT, previous stroke, and previous evaluation at another hospital as covariates. Continuous predictors were modeled per year, NIHSS point, and ODT hour, respectively. Adjusted odds ratios (aOR) with 95% CI were reported, with p < 0.05 considered statistically significant.

A total of 1,460 patients were included, 501 (34.3%) of whom had PCS, with a median age of 70 years (IQR 59-80). We found significant differences in median ODT between PCS and ACS (13 h, IQR 5-46 vs. 8.5 h, IQR 4-20; p < 0.001) and in IVT rates. In the adjusted analysis, each additional hour of ODT was associated with lower odds of IVT (aOR 0.88, 95% CI 0.85-0.92), whereas stroke circulation was not independently associated with IVT (PCS vs. ACS: aOR 0.66, 95% CI 0.39-1.11). Higher admission NIHSS was associated with higher odds of IVT (aOR 1.06 per point, 95% CI 1.03-1.09).

Patients with posterior circulation stroke had longer prehospital delays and lower observed rates of intravenous thrombolysis than those with anterior circulation stroke. However, stroke circulation was not independently associated with IVT after adjustment for ODT and other clinically relevant covariates. These findings highlight early recognition and reduction of prehospital delay as potential targets for improving access to reperfusion therapy in Latin America.