Study Shows Operator-Adjudicated mTICI Scores Tend to Overestimate Reperfusion After Endovascular Stroke Treatment
August 29, 2018—Operators tend to overestimate the degree of reperfusion compared with the core lab adjudication after endovascular treatment of acute ischemic stroke; however, this does not affect the accuracy of outcome prediction, concluded Guang Zhang, MD, et al for the MR CLEAN registry investigators in a study published online in Stroke.
The study compared operators' modified Treatment In Cerebral Ischemia (mTICI) scores with core lab mTICI scores in patients in the in the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) registry. The mTICI score is commonly assessed by local operators after the procedure, but in clinical trials and registries, it is evaluated in by an imaging core lab, noted the investigators.
As summarized in Stroke, the analysis included all patients with an intracranial carotid or middle cerebral artery occlusion with anteroposterior and lateral digital subtraction angiography runs. Operators determined the mTICI score immediately after endovascular treatment. Core lab neuroradiologists were blinded to clinical characteristics and assessed mTICI scores based on pre- and postintervention digital subtraction angiography.
In a study population of 1,130 patients, the investigators determined the agreement between operator and core lab mTICI scores and their value in the prediction of outcome (score on modified Rankin Scale [mRS] at 90 days). The proportion of agreement between operator and core lab mTICI score was 56% (95% confidence interval [CI], 54%–59%). In 33% (95% CI, 31%–36%), mTICI was overestimated by operators.
Operators reported a higher rate of successful reperfusion than the core lab (77% vs 67%; difference 10% [95% CI, 6%–14%]; P < .001). There were 252 of 763 patients (33%) who were determined to show incomplete reperfusion by the core lab (mTICI < 3) score in whom the local read was mTICI 3.
Multivariable logistic regression models containing either core lab–scored or operator-scored successful reperfusion predicted outcome on the full (C-statistic of both models: 0.76) or dichotomized mRS (mRS, 0–2; C-statistic of both models, 0.83) equally well, reported the investigators in Stroke.