International team under supervision of Yvo Roos reports on Two-Year Outcome after Endovascular Treatment for Acute Ischemic Stroke (Mr Clean study) in New England Journal of Medicine

Several trials involving patients with acute ischemic stroke have shown better functional outcomes with endovascular treatment than with conventional treatment at 90 days after initiation of treatment. However, results on long-term clinical outcomes are lacking.

We assessed clinical outcomes 2 years after patients were randomly assigned to receive either endovascular treatment (intervention group) or conventional treatment (control group) for acute ischemic stroke. The primary outcome was the score on the modified Rankin scale at 2 years; this scale measures functional outcome, with scores ranging from 0 (no symptoms) to 6 (death). Secondary outcomes included all-cause mortality and the quality of life at 2 years, as measured by means of a health utility index that is based on the European Quality of Life–5 Dimensions questionnaire (scores range from −0.329 to 1, with higher scores indicating better health).

Of the 500 patients who underwent randomization in the original trial, 2-year data for this extended follow-up trial were available for 391 patients (78.2%) and information on death was available for 459 patients (91.8%). The distribution of outcomes on the modified Rankin scale favored endovascular treatment over conventional treatment (adjusted common odds ratio, 1.68; 95% confidence interval [CI], 1.15 to 2.45; P = 0.007). The mean quality-of-life score was 0.48 among patients randomly assigned to endovascular treatment as compared with 0.38 among patients randomly assigned to conventional treatment (mean difference, 0.10; 95% CI, 0.03 to 0.16; P = 0.006). The cumulative 2-year mortality rate was 26.0% in the intervention group and 31.0% in the control group (adjusted hazard ratio, 0.9; 95% CI, 0.6 to 1.2; P = 0.46).

In this extended follow-up trial, the beneficial effect of endovascular treatment on functional outcome at 2 years in patients with acute ischemic stroke was similar to that reported at 90 days in the original trial. (Funded by the Netherlands Organisation for Health Research and Development and others; MR CLEAN Current Controlled Trials number, ISRCTN10888758, and Netherlands Trial Register number, NTR1804, and MR CLEAN extended follow-up trial Netherlands Trial Register number, NTR5073.)

Original article: Lucie A. van den Berg et al. Two-Year Outcome after Endovascular Treatment for Acute Ischemic Stroke (2017). N Engl J Med 2017; 376:1341-1349 (