Association between initial NIHSS score and recanalization rate after endovascular thrombectomy.

BACKGROUND

National institutes of Health Stroke Scale (NIHSS) score and the presence of successful recanalization are crucial determinants of clinical outcome in patients with major artery occlusion. However, it is unknown whether successful recanalization rate after endovascular therapy (EVT) depends on NIHSS score.

METHODS

From our prospective EVT registry, data on patients with an occlusion at the internal carotid artery or middle cerebral artery were analyzed. Successful recanalization was judged as positive when reperfusion of the thrombolysis in cerebral infarction (TICI) scale ≥2b was observed. Successful recanalization rate was also evaluated based on the NIHSS score subgroups: 0-8, 9-16, 17-24, and >24. Multivariate regression analysis was used to evaluate the impact of NIHSS score on successful recanalization.

RESULTS

We studied 183 patients (age 76 [68-83], male 110 [60%], NIHSS score 19 [14-24]). One hundred and forty-six (80%) patients had the successful recanalization. Patients achieved the recanalization had lower NIHSS score as 18 (12-23), contrary those failed it had higher NIHSS score as 24 (20-27) (p < .001). Successful recanalization rate was correlated to the NIHSS score grade; 100% in the NIHSS 0-8 group, 88% in 9-16, 81% in 17-24, and only 60% in >24 (p < .001). Multivariate regression analysis showed NIHSS score was an independent parameter of recanalization (odds ratio 0.905 [95%CI 0.837-0.979], p = .013).

CONCLUSION

NIHSS score may serve as a predictor of successful recanalization. Recanalization is relatively easier in mild stroke than in those with severe stroke.