Tempus vincit omnia--analyzing the effect of time on angiographic results after mechanical thrombectomy

Purpose: Procedural times and angiographic results are relevant predictors of outcome after EVT. How time influences the patients' chance of achieving a favorable outcome with a distinct angiographic result is unknown. This study is the first to investigate the effect of time on different TICI scores. Methods: Retrospective analysis of 164 patients who were successfully treated for an LVO of the anterior circulation. Clinical and angiographic data were taken from our prospective data base. Angiographic results were re-graded according the novel expanded TICI (eTICI) score[1]. Multiple logistic regression analysis were performed calculating the effect of groin to recanalization times for different TICI scores and odds ratios as well as changes in the odds for achieving a favorable outcome per minute were calculated. Results: For the multiple logistic regression model to predict a favorable outcome at 90d eTICI results were significant contributors (p < 0.001). Additionally there was a significant difference between eTICI2b67 and eTICI3 and eTICI2c and eTICI3 respectively with p < 0.001 (OR:0.038) and p = 0.0297 (OR:0.417). The change of odds over time in our model can be expressed as a formula. For example let the initial odds of achieving a favourable outcome for patients with mean age, and eTICI2b67 after 40 treatment minutes be 2.25. To see how the Probabilities would shift if the same patient got his eTICI2b67 after 80 minutes we either look into our model or calculate the new odd. Conclusion: Achieving certain angiographic results at different time points is associated with different probabilities of favorable outcome. Understanding the correlation of time and angiographic success may help to refine endovascular treatment.