DIMR Score: A Tool for Determining the Destination of LVO Patients After Thrombolysis

BackgroundStroke patients with large vessel occlusion (LVO) benefit from thrombolysis (tPA) and mechanical thrombectomy (MT). We aim to characterize triaging patterns in these patients, specifically those who go to perfusion-based imaging first or direct to angio in the drip-and-ship model. Furthermore, we propose that select patients may benefit from CTP prior to MT. MethodsA total of 270 patients with acute ischemic stroke secondary to LVO/MeVO were retrospectively evaluated from January 2018 to June 2022. These patients received intravenous tPA from the outside hospital and were transferred for the intention of MT. We compared baseline characteristics between those who received CTP upon arrival and those who went either directly to the angiography suite (DTA) along with logistic regression and functional outcomes. ResultsPredictors of CTP utilization over DTA was the presence of an M3 occlusion (11.3% vs. 1.7%, p=0.005) and PCA occlusion (12.9% vs. 3.4%, p=0.015). The DTA approach was higher in M1 MCA occlusions (43.2% vs. 27.4%, p=0.038) and basilar occlusions (7.6% vs. 0, p=0.026). DTA patients had a higher NIHSS at the spoke (median NIHSS 15 [9-21] vs. 9 [4.75-14], p<0.001) and the hub (14 [7-20] vs. 7 [3-15.75], p<0.001). There was no significant difference between the DTA and CTP groups in regards to mRS at 90 days (39% vs. 48.4%, p=0.101). ConclusionIn the drip-and-ship model, NIHSS and location of an occlusion on initial CTA guide CTP utilization in LVO/ MeVO patients. Long term functional outcomes are not significantly affected by arrival at CTP over DTA. Patients whose transfer is delayed, improve after thrombolysis, present with a MeVO, or are limited by resources at the CSC may benefit from transfer to CT over a DTA approach. We propose this DIMR score may help guide triaging of patients who have an intracranial occlusion and receive thrombolysis.