Introduction: All eligible patients receive IV tPA prior to thrombectomy, but the effect of IV tPA on recanalization prior to and following thrombectomy remains unclear. The purpose of this analysis was to determine the effect of IV tPA on early recanalization obviating the need for thrombectomy, as well as the effect of tPA on recanalization rates.
Methods: All patients with a CTA-proven LVO in the ICA, M1, proximal M2, or basilar artery in whom thrombectomy was planned over a 24 month period were included. CTA was performed at the first presenting hospital, whether PSC or CSC, and not repeated on arrival for transfer patients. We defined “successful” treatment with IV tPA as TICI 2b or 3 reperfusion, such that thrombectomy was not performed. Time from tPA to start of angiography was divided into 30 minute intervals. We also examined the effect of transfer status and the relationship between tPA and overall recanalization after thrombectomy.
Results: We identified 310 patients, 190 who received tPA prior to planned thrombectomy and 120 who did not. Of all patients, 178 (57%) were transfers, including 111/190 (58%) in the tPA group. The rates of recanalization with IV tPA are summarized in Table below. Overall rates of successful recanalization (TICI 2b or better) before thrombectomy are low, especially when time between IV tPA and start of angiography is minimized. Successful tPA recanalization rates were 11.7% for transfer patients and 6.3% for non-transfer patients, likely due to faster workflow at the comprehensive stroke center. The rates of overall successful recanalization (TICI 2b or better) were 77.4% in the tPA group (23.8% TICI 2b; 53.6% TICI 2c/3) and 83.6% (22.4% TICI 2b; 61.2% TICI 2c/3) in the no tPA group.
Conclusion: Early recanalization rate following IV tPA prior to thrombectomy is low, especially when workflow is optimized to minimize time between tPA bolus and start of angiography. Pre-treatment with IV tPA did not increase recanalization rates after thrombectomy.