1. Long-term clinical outcome following emergency MR-based reperfusion therapy for acute middle cerebral artery occlusion Department of Stroke Treatment, Shonan Kamakura General Hospital Stroke Center, Kamakura City, Japan Mori T, Nakazaki M, Tajiri H, Iwata T, Uesugi T, Soga N SNR2010, Bologna

2. Background and purpose Long-term clinical outcome following emergency MR-based reperfusion therapy for acute ischemic stroke patients remains uncertain. The aim of our retrospective study was to investigate long-term clinical outcome following emergency MR-based reperfusion therapy for acute middle cerebral artery (MCA) occlusion

3. Patients Included for retrospective analysis were acute stroke patients 1)who were admitted to our institution between Oct 10, 2005 and Sep 10, 2009, 2)who were admitted within 6 hours from stroke onset, 3)who underwent emergency MR study, which showed no visualization of the MCA 4)who presented neurological symptoms of NIHSS score of 5 or more due to acute MCA 5)who underwent emergency reperfusion therapy

4. Emergency Reperfusion Therapy Intravenous rt-PA was performed in patients within 3 hours of stroke onset. Endovascular treatment was performed in patients where intravenous t-PA was not appropriate to or in whom intravenous rt-PA could not be injected within 3 hours from onset.

5. Evaluation Baseline features: age, sex, onset-to-arrival time (OTA), onset-to-needle time(OTN), NIHSS score on admission (NIHSS adm), Clinical outcome modified Rankin scale at 3 months Long-term survival

6. Results Overall: 601 ischemic stroke patients OAT< 6hrs MR-based reperfusion therapy for the MCA occlusion: 42 patients Intravenous t-PA 22 patients (group R) Endovascular treatment 20 patients (group E) Emergency MR imaging

7. DWI, T2WI, T2*, MRA, PWI DWIPWIMRA

8. Emergency Endovascular Treatment Intra-arterial thrombolysis Balloon angioplasty Thrombectomy

9. Features of the 42 patients Age （ mean±SE ）： 75.3±1.5 years old Sex (man) ： 25 （ 60 ％） OTA （ median ）： 0.93 hours OTN (median) ： 2.75 hours NIHSS adm (median) ： 12 NIHSS at discharge (median) ： 9 Hospitalization period （ median ）： 9.5 days DWI-ASPECT score (median) ： 8

10. Long-term Clinical Outcome of the 42 patients Follow-up duration （ median ）： 113days （ 3.8 months) Alive ： 34 pts(81 %) Dead ： 8 pts(19 %) ｍ RS at 3 months 0-2 ： 14 pts （ 33.3 ％） 3-5 ： 20 pts （ 47. 7 ％） 6 ： 8 pts （ 19 ％）

11. Multiple linear regression analysis for 3-month mRS in the 42 patients ｍ RS= 0,1,2,3,4,5,6, emergency Reperfusion Therapy (eRT) ： 1 ＝ group E, 2=group R, Sex: 0=woman 1=man, adm : admission, Af (atrial fibrillation) ： 0=no, 1=yes non-standardized regression coefficient 95% CI p -3.434 -8.406 - 1.538 0.170 eRT (1 ， 2) 1.329 0.080 - 2.578 0.038 Age 0.041 -0.015 - 0.096 0.148 SEX(0 ， 1) 0.284 -0.915 - 1.483 0.634 NIHSS adm 0.133 0.075 - 0.191 0.000 Af (0 ， 1) -0.488 -1.678 - 0.702 0.411

12. Cumulative survival probability (n=42) for any death by Kaplan-Meier method 76.1% days 1 Y2 Y

13. Cox proportional hazard model for survival coefficienthazard ratio95%CI p eRT (1, 2)7.92697.901.219-5969374.81 0.044 Age0.2651.301.005 - 1.69 0.045 Sex (0, 1)8.1253377.641.852-6159224.43 0.034 NIHSS adm0.3121.361.04 - 1.78 0.021 Af (0, 1)-4.153.010.00 - 0.81 0.039 Emergency reperfusion therapy (eRT) ： 1 ＝ group E, 2=group R, adm: admission Sex: 0=woman 1=man, Af;( atrial fibrillation) ： 0=no, 1=yes

14. Cumulative survival probability (n=42) for any death by Kaplan-Meier method Cox hazard : p=0.044 group R = 68.56 % (Intravenous rt-PA) group E = 85.23 % (Endovascular) days 1 Y

15. Differences between group E and R group Egroup R n=20n=22 Age (yrs; average+-SD)74.9 +- 9.375.7 +- 10.6n.s. Sex(man; %)16 (80.0%)9 (40.9%)p<0.05 OAT (hrs: average +- SD)2.0 +- 0.290.86 +- 1.60p<0.001 NIHSS (median)13.518.5p=0.11 DWI-ASPECT (median)8.57.5p=0.28 p

16. Conclusion After emergency MR-based reperfusion therapy, long-term survival probability was 76.1% and favorable 3-month clinical outcome was achieved in 33.3% of patients. Young, female patients with lower NIHSS score were alive longer. Patients who underwent endovascular treatment may be alive longer and have better clinical outcome than intravenous rt-PA.