Abstract WP46: Blood Pressure, Clinical Improvement And Recanalization Following Acute MCA Occlusion
Background: Blood pressure (BP) drop in the first 24 hours after stroke onset may occur in response to vessel recanalization. Clinical improvement could be due to recanalization or better collateral flow with persistent occlusion. We hypothesize that patients with combination of significant improvement on the NIHSS and a drop in BP at 24hr post tPA is associated with recanalization.
Methods: We included intravenous t-PA patients from the Lesion Evolution of Stroke Ischemia On Neuroimaging (LESION) registry who had pre-treatment and 24 hour MRA scan, NIHSS scores at those times and an M1 MCA occlusion at baseline, but excluded those on pressors, pre tPA SBP<120 and tandem ICA occlusion. We classified recanalization status on the 24 hour MRA as none, partial or complete. We abstracted all BP measurements for the first 24 hours from the chart and calculated BP drop as the difference of the triage pre-tPA BP and the average of the last 3 hour readings preceding the 24 hour MRI. NIHSS improvement was defined as ≥4points improvement on NIHSS or NIHSS of 0 at 24hour. Patients with combination of drop in BP and NIHSS improvement were compared with others for recanalization status on 24hr MRA by Kendall Tau-b test.
Results: Seventeen patients met the study criteria. There were 13 women, the mean age was 76 years and the median baseline NIHSS was 15. On the 24 hour MRA, 3, 8 and 6 patients had none, partial and complete recanalization, respectively. Patients with NIHSS improvement and a SBP drop ≥20 mmHg were more like to have recanalization at 24 hrs (57% Vs 0%, p=0.03). Similar patterns were seen for patients with NIHSS improvement and DBP drop ≥5mmHg (50% Vs 0%, p=0.04) or MAP drop ≥20mmHg (50% Vs 0%, p=0.04). Complete recanalization was only associated with the combination of NIHSS improvement with SBP drop ≥ 20mmHg (66% Vs 0%, p=0.04). A significant association was not found for recanalization with NIHSS improvement alone or drop in BP alone.
Conclusion: There is an association of clinical improvement and BP drop in patients who recanalize. Bedside clinical information may be useful in the management of stroke patients.
- © 2012 by American Heart Association, Inc.