Background: The pathophysiology and optimal management of blood pressure changes in acute ischemic stroke remain unknown. Blood pressure guidelines do not consider patient-specific or serial data on dynamic blood pressure readings. We investigated continuous blood pressure data during endovascular therapy for acute stroke to discern changes associated with collaterals, recanalization and reperfusion.
Methods: Continuous monitoring blood pressure data was collected in consecutive cases of endovascular therapy for acute ischemic stroke due to ICA or proximal MCA occlusion. Angiography details were independently analyzed to document site of arterial occlusion, baseline collateral grade, time of device deployments, time of recanalization, time of final reperfusion, final AOL recanalization and final TICI reperfusion. Statistical analyses correlated instantaneous and serial blood pressure changes with these angiographic parameters.
Results: 80 patients (median age 73 years; 33 women) were studied. Arterial lesions included 37 ICA and 41 proximal M1 MCA occlusions. Collateral grade prior to intervention included 2 ASITN grade 4, 26 grade 3, 23 grade 2, 6 grade 1 and 0 grade 0. oTICI2C reperfusion scores after thrombectomy included 2 TICI 3 (100%), 22 TICI 2C (90-99%), 25 TICI o2B (67-89%), 9 TICI m2B (50-66%), 19 TICI 2A (<50%) and 3 TICI 0/1. More robust collateral grade was associated with greater reperfusion scores (r=0.32, p=0.028). The change in blood pressure (ΔBP) from earliest BP to time of recanalization was mean 59% of ΔBP during the entire procedure. Better collaterals were associated with lower BP prior to recanalization (r=-0.377, p=0.012). Lower BP prior to recanalization was linked with greater TICI reperfusion (r=-0.242, p=0.050). Higher TICI reperfusion scores were also associated with a greater drop or ΔBP at the time of recanalization (r=0.269, p=0.031). AOL recanalization was not related to ΔBP.
Conclusions: Collaterals and reperfusion, but not recanalization, mediate blood pressure changes in acute ischemic stroke. Prospective, precision medicine stroke studies should leverage patient-specific, real-time data on continuous blood pressure with imaging correlates to define BP goals of future in-hospital management.