Endovascular Stroke Treatment Shows Sustained Response Up to 2 Years

The response to endovascular treatment for acute ischemic stroke after 2 years was as good as in the first 90 days, according to the extended results of the MR CLEAN trial, reported in a recent issue of The New England Journal of Medicine.¹

The MR CLEAN study (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) compared outcomes of conventional care (control group, n=267) with conventional care plus endovascular treatment within 6 hours after stroke onset (intervention group, n=233) in 500 patients with acute ischemic stroke due to proximal intracranial occlusion of the anterior circulation.^2-8 Conventional care was defined according to national and international guidelines and in some cases included intravenous (IV) administration of alteplase. The original trial results showed improved functional recovery in the intervention group compared with the control group at 90 days.⁸

There was some reassignment during the trial: 7 of the patients scheduled for endovascular treatment did not receive it and one assigned only to conventional treatment also received endovascular therapy. At the end of 2 years, outcomes data was available for only 391 of the original patients.

The odds ratio (OR) for functional independence (measured as 0-2 on the modified Rankin scale) was 1.67 at 90 days and 1.68 at 2 years. In addition, 32.6% of patients were functionally independent at 90 days and 37.1% were functionally independent at 2 years.

Although primary outcomes were essentially the same at 2 years compared with 90 days, the investigators reported some notable differences in secondary outcomes measuring mortality and quality of life scores, and in the number of patients who had better outcomes after 2 years. Risk of mortality at 90 days was similar in the intervention and the control group. The between-group difference was greater at 2 years; however, this difference did not achieve statistical significance. 

The researchers suggested this contradicted previous studies indicating a sustained effect to intravenous (IV) alteplase and endovascular therapies.^9-13 They attributed the MR CLEAN result to the impact of rehabilitation therapy in the first months after a stroke, which may have prevented patients from recognizing the full limitations to their daily routines until months later when rehabilitation ended.

The results of the extended follow-up to the MR CLEAN trial were similar to the results reported at 90 days, and showed sustained effects from early intervention with endovascular therapy that continued up to 2 years.

References

1. van den Berg LA, Dijkgraaf MGW, Berkhemer OA, et al. Two-year outcome after endovascular treatment for acute ischemic stroke. N Engl J Med. 2017;376:1341-1349.
2. Berkhemer OA, Fransen PSS, Beumer D, et al. A randomized trial of intraarterial treatment for acute
3. Goyal M, Demchuk AM, Menon BK, et al. Randomized assessment of rapid endovascular treatment of ischemic stroke. N Engl J Med. 2015;372:1019-30.
4. Saver JL, Goyal M, Bonafe A, et al. Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke. N Engl J Med. 2015;372:2285-2295.
5. Campbell BCV, Mitchell PJ, Kleinig TJ, et al. Endovascular therapy for ischemic stroke with perfusion-imaging selection. N Engl J Med. 2015;372:1009-1018.
6. Jovin TG, Chamorro A, Cobo E, et al. Thrombectomy within 8 hours after symptom onset in ischemic stroke. N Engl J Med. 2015; 372: 2296-306.
7. Goyal M, Menon BK, van Zwam WH, et al. Endovascular thrombectomy after large-vessel ischaemic stroke: a metaanalysis of individual patient data from five randomised trials. Lancet. 2016;387:1723-1731.
8. Fransen PSS, Beumer D, Berkhemer OA, et al. MR CLEAN, a multicenter randomized clinical trial of endovascular treatment for acute ischemic stroke in the Netherlands: study protocol for a randomized controlled trial. Trials. 2014;15:343.
9. Schmitz ML, Simonsen CZ, Hundborg H, et al. Acute ischemic stroke and long-term outcome after thrombolysis: nationwide propensity score-matched follow-up study. Stroke. 2014;45:3070-3072.
10. Kwiatkowski TG, Libman RB, Frankel M, et al. Effects of tissue plasminogen activator for acute ischemic stroke at one year. N Engl J Med. 1999;340:1781-1787.
11. Broderick JP, Palesch YY, Demchuk AM, et al. Endovascular therapy after intravenous t-PA versus t-PA alone for stroke. N Engl J Med. 2013;368:893-903.
12. Palesch YY, Yeatts SD, Tomsick TA, et al. Twelve-month clinical and quality-of-life outcomes in the Interventional Management of Stroke III Trial. Stroke. 2015;46:1321-1327.
13. Davalos A, Cobo E, Chamorro A, et al. Randomized trial of revascularization with Solitaire FR device versus best medical therapy in the treatment of acute stroke due to anterior circulation large vessel occlusion presenting within eight hours of symptom onset (REVASCAT Trial) — final results at 12 months. Presented at: International Stroke Conference 2016. February 17-19, 2016; Los Angeles, Calif.