Abstract TP26: Endovascular Therapy in Patients With Low NIHSS Score on Presentation

Abstract

Introduction: Approximately 2/3 of all AIS present with NIHSS 0-5. While it has been demonstrated that LVO can be found in ~10-20% of all low NIHSS patients, outcome data in this population remains scarce. Indeed, only 14/1766 patients in the recent endovascular RCTs had baseline (b) NIHSS in the 0-5 range. Yet, the presence of LVO in the setting of low NIHSS is associated with ~10-fold increase in subsequent deterioration. We aim to describe the outcomes in a large cohort of low NIHSS patients undergoing thrombectomy. Methods: Patients derived from a large prospective multicenter international stent-retriever registry (Trevo Registry, n=2,010). Baseline and outcome variables were compared according to bNIHSS 0-8 vs >8 and bNIHSS 0-5 vs >5. The primary and secondary efficacy endpoints were the rates of 90-day mRS 0-2 and mTICI 2b-3, respectively. Safety endpoints included sICH and 90-day mortality. Results: A total of 1,985 patients were included. As compared with patients with higher baseline NIHSS, low baseline NIHSS (0-8, n=342; 0-5, n=160) patients were younger, had less comorbidities and better functional status, more frequently had MCA-M2 or vertebrobasilar occlusions, less frequently received IV tpa, and underwent thrombectomy at later times (Table 1). The reperfusion outcomes were nearly the same. There were no significant differences in procedure-related complications, which were overall low (Table 2). The rates of 90-day mRS 0-2 were significantly higher in the lower NIHSS patients (p<0.001); however, ~20% of those patients were not independent and ~7% were dead at 90 days despite presenting with low clinical severity. Conclusion: Despite safe and efficacious endovascular reperfusion, low-NIHSS LVO patients have a relatively high proportion of bad outcomes. This supports the notion that many of "mildly" presenting patients do not fare well. A randomized clinical trial including immediate endovascular treatment in this patient population is warranted.