Association between computed tomography perfusion and the effect of intravenous alteplase prior to endovascular treatment in acute ischemic stroke

Abstract

Purpose: Intravenous alteplase (IVT) prior to endovascular treatment (EVT) is neither superior nor noninferior to EVT alone in acute ischemic stroke patients. We aim to assess whether the effect of IVT prior to EVT differs according to CT perfusion (CTP)-based imaging parameters.

Methods: In this retrospective post hoc analysis, we included patients from the MR CLEAN-NO IV with available CTP data. CTP data were processed using syngo.via (version VB40). We performed multivariable logistic regression to obtain the effect size estimates (adjusted common odds ratio a[c]OR) on 90-day functional outcome (modified Rankin Scale [mRS]) and functional independence (mRS 0-2) for CTP parameters with two-way multiplicative interaction terms between IVT administration and the studied parameters.

Results: In 227 patients, median CTP-estimated core volume was 13 (IQR 5-35) mL. The treatment effect of IVT prior to EVT on outcome was not altered by CTP-estimated ischemic core volume, penumbral volume, mismatch ratio, and presence of a target mismatch profile. None of the CTP parameters was significantly associated with functional outcome after adjusting for confounders.

Conclusion: In directly admitted patients with limited CTP-estimated ischemic core volumes who presented within 4.5 h after symptom onset, CTP parameters did not statistically significantly alter the treatment effect of IVT prior to EVT. Further studies are needed to confirm these results in patients with larger core volumes and more unfavorable baseline perfusion profiles on CTP imaging.

Keywords: Alteplase; CT perfusion; Ischemic core; Stroke; Thrombectomy.

Fig. 1

Flowchart of patient selection. CTP, CT perfusion; EVT, endovascular treatment; IVT, intravenous alteplase

Fig. 2

Probability of functional independence for CTP-estimated ischemic core volume adjusted for potential confounders. Associations are shown for patients who received IVT prior to EVT (blue) and who underwent EVT alone (red). The horizontal bars above and below the graph represent the CTP-estimated ischemic core volumes for patients who did achieve or did not achieve functional independence at 90 days, respectively. Each vertical line represents one patient. Patients with IVT prior to EVT are shown in blue and patients who underwent EVT alone are shown in red. CTP, computed tomography perfusion; EVT, endovascular treatment; IVT, intravenous alteplase; mRS, modified Rankin Scale score

Fig. 3

Distribution of scores on the Modified Rankin Scale score at 90 days in the MR CLEAN-NO IV CTP subgroup for patients with (n=196) and without (n=26) a target mismatch (TMM) profile on CTP imaging who underwent IVT and EVT vs. EVT alone. CTP, computed tomography perfusion; mRS, modified Rankin Scale score at 90 days