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7 Outcomes of medically-treated patients with M2-segment middle cerebral artery occlusion. Results from the prospective multicentral international cohort study INTERRSeCT
  1. B Menon1,
  2. M Najm1,
  3. F Al-Ajlan2,
  4. M Almekhlafi3,
  5. J Puig4,
  6. M Castellanos5,
  7. D Dowlatshahi6,
  8. A Calleja7,
  9. S Sohn8,
  10. S Ahn8,
  11. A Poppe9,
  12. R Mikulik10,
  13. N Asdaghi11,
  14. T Field12,
  15. A Jin13,
  16. T Asil14,
  17. J Boulanger15,
  18. E Smith1,
  19. S Coutts1,
  20. P Barber1,
  21. S Bal1,
  22. S Subramanian1,
  23. S Mishra16,
  24. A Trivedi17,
  25. S Dey1,
  26. M Eesa1,
  27. T Sajobi1,
  28. M Goyal1,
  29. M Hill1,
  30. A Demchuk1
  1. 1University of Calgary, calgary, AB, Canada
  2. 2King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
  3. 3University of Calgary, Calgary, AB, Canada
  4. 4University Hospital Dr Josep Trueta, Girona, Spain
  5. 5University Hospital Dr Josep Trueta address, Girona, Spain
  6. 6University of Ottawa, Ottawa, ON, Canada
  7. 7Univ de Valladolid, Valladolid, Spain
  8. 8Keimyung Univ., Daegu, Korea, Republic of
  9. 9University of Montreal, Montreal, QC, Canada
  10. 10St. Ann’s Univ Hosp and Masaryk University, Brno, Czech Republic
  11. 11University of Miami, Miami, FL
  12. 12University of British Columbia, Vancouver, BC, Canada
  13. 13Queen’s University, Kingston, ON, Canada
  14. 14Bezmialem Vakif Üniversitesi Tip Fakültesi Hastanesi, Istanbul, Turkey
  15. 15Greenfield Park, QC, Canada
  16. 16Gold Coast University Hospital, Gold Coast, Australia
  17. 17University of Manitoba, Winnipeg, MB, Canada


Background Patients with proximal arterial M2-segment of the Middle Cerebral Artery (M2-MCA) occlusions were largely excluded from endovascular stroke trials. Current American Stroke guidelines are conservative in recommending thrombectomy for such patients. We sought to assess the natural history of medically- treated M2-MCA occlusion patients.

Methods This is a prospective multi-central international cohort study of all acute ischemic stroke patients with intracranial occlusions on baseline imaging. Patients with M2-MCA occlusions were identified on baseline CT angiography and non-endovascular-treated patients were included. The M2-MCA segment was defined as the first-order branch of the proximal MCA, excluding the anterior temporal artery. The M2-MCA was further classified according to its visually-assessed diameter relative to the M1-MCA into: M1-equivalent (>90% of the diameter of the M1-MCA), Major (50%–90%), Minor (<50%). Follow-up CTA 4 hours from baseline imaging was used to assess recanalization using the revised arterial occlusive lesion (rAOL).

Results Out of 575 patients in the entire study, there were a total of 184 M2-MCA occlusions seen. Of those, 104 patients were NOT treated with endovascular therapy: 90 patients (86.5%) received IV TPA and 14 (23.5%) patients conservative management. Among those, 23.1% (24/104) M1-equivalent, 66.4% (69/104) major, and 9.6% (10/104) minor M2-MCA. The median age was 76 years (interquartile range 19 years). The median (IQR) baseline NIHSS score of the cohort was 9 (9): M1-equivalent 12(10), major 9 (9), minor 7 (8). The median baseline ASPECTS was 9 overall and in all M2 groups. Successful recanalization was observed in 44.2% (46/104) of the medical M2 occlusion cohort overall. TPA group was 47.8% (43/90) and conservative group 21.4% (3/14). With IV TPA successful recanalization occurred in 30% (6/20) of M1-equivalent, 50% (31/62) of major, and 75% (6/8) of minor M2-MCA occlusions. In conservative management group successful recanalization occurred in 25% (1/4) of M1-equivalent, 14.3% (1/7) of major, and 50% (1/2) of minor M2-MCA occlusions. Good functional outcome (mRS 0–2) at 90 day was observed in 62.1% (64/104) of the cohort overall. Among those with successful recanalization, 76.1% (35/46) achieved good outcome. With IV TPA, the proportion of patients achieving independent functional outcome was 45% (9/20) with M1-equivalent, 70.5% (43/61) of major, and 62.5% (5/8) of minor M2-MCA occlusions. In the conservative management group, the proportion of patients achieving independent functional outcome at 90 day was 25% (1/4) with M1-equivalent, 71.4% (5/7) of major, and 50% (1/2) of minor M2-MCA occlusions. In logistic regression analyses, successful recanalization predicted independent functional outcome (OR 2.9, 95% CI 1.02 to 8.1, p 0.046). Age (OR 0.89, 95% CI 0.84 to 0.94, p<0.001) and baseline NIHSS (OR 0.90, 95% CI 0.83 to 0.97, p 0.009) were negative predictors of good outcomes.

Conclusion While over one half of medically-treated patients with M2-MCA segment occlusions achieve independent outcome, a subset of patients suffers poor functional outcomes at 90 days. Successful recanalization are associated with higher odds of independent functional outcome.

Disclosures B. Menon: None. M. Najm: None. F. Al-Ajlan: None. M. Almekhlafi: None. J. Puig: None. M. Castellanos: None. D. Dowlatshahi: None. A. Calleja: None. S. Sohn: None. S. Ahn: None. A. Poppe: None. R. Mikulik: None. N. Asdaghi: None. T. Field: None. A. Jin: None. T. Asil:None. J. Boulanger: None. E. Smith: None. S. Coutts: None. P. Barber: None. S. Bal: None. S. Subramanian: None. S. Mishra: None. A. Trivedi: None. S. Dey: None. M. Eesa: None. T. Sajobi: None. M. Goyal: None. M. Hill: None. A. Demchuk: None.

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