Abstract W P56: Using The M2 Vessel Diameter And Baseline NIHSS To Identify Which M2 Occlusions Should Be Treated Endovascularly?
Introduction: IV tPA is the primary acute treatment for M2 occlusions yet outcomes and recanalization rates are less than optimal. Endovascular treatment may be a more suitable treatment option in some but not all M2 occlusions yet are excluded from most current endovascular trials. Current methodologies to characterize M2s are complex and quite subjective. A simple and practical approach to evaluating M2s quickly for endovascular treatment is needed. We measured M2 cross-sectional diameter to determine if this method predicted 24-hour infarct volumes.
Methods: Patients from the ongoing prospective multicenter INTERRSECT recanalization study with an M2 occlusion identified by baseline CTA were included. Two readers measured M2 diameter on baseline CTA at the most distal point of normal vessel upstream to the clot by consensus. Recanalization (modified AOL score 2-3) was assessed on 4 hour follow-up CTA. Infarct volume was measured on 24 hr CT/MRI.
Results: 103 patients (mean age 74.1 yrs, SD=12.7; 46.5% male; median baseline NIHSS 8, IQR=7) had M2 occlusion on baseline CTA. 76/103 received IV t-PA. Recanalization was noted in 46/92 (50%) patients. Median 24-hr infarct volume was 4.28 ml (IQR=22.67 ml). In multivariable linear regression, M2 diameter (p<0.01) and baseline NIHSS (p=0.01) were associated with final infarct volume but not recanalization (p=53). Median final infarct volume was 41.6 ml (IQR=50.4) in patients with M2 diameter>2mm and baseline NIHSS>5 vs < 10 ml in all the other 3 groups (p<0.01; equality of medians test; see figure).
Conclusion: Patients with M2 diameter > 2 mm just proximal to the occlusion and baseline NIHSS > 5 have much higher final infarct volumes suggesting a role for ultra-early recanalization that is offered by endovascular treatment. Such patients could be selected for endovascular therapy in future trials or clinical practice.
Author Disclosures: R.M.R. Appireddy: None. B.K. Menon: None. M. Horn: None. P. Wee: None. S. Patil: None. T. Stewart: None. J. Desai: None. P.A. Burns: None. J. Puig: None. S. Sohn: None. A. Calleja Sanz: None. D. Dowlatshahi: None. A. Poppe: None. N. Asdaghi: None. R. Mikulik: None. T. Asli: None. J. Boulanger: None. S. Ahn: None. A. Jin: None. M. Francois: None. M. Goyal: None. A.M. Demchuk: Honoraria; Modest; Covidien honoraria for CME. Research Grant; Significant; Unrestricted grant for ESCAPE trial: Covidien.
- © 2015 by American Heart Association, Inc.