Abstract 185: Risk-adjusted Comparison of Good Functional Outcome at 3 Months after Primary Endovascular Therapy or Intravenous Thrombolysis Alone. Results from an Observational, Population-based Study

Abstract

Background: Evidence clearly supports intravenous thrombolysis (IVT) as first-line therapy for AIS. Yet, endovascular treatment (EVT) might be an alternative for patients with IVT contraindications. Our aim was to study whether patients treated with primary EVT in daily practice did as well as those treated with IVT alone in terms of functional outcome. Methods: Observational, population-based study of consecutive AIS patients treated with either isolated EVT or IVT within 2011 and 2012 in Catalonia. Patients were prospectively included in a health-administration based registry with external monitoring of completeness. Inclusion criteria: EVT or IVT delivered under routine conditions. Exclusion criteria: combined IVT+EVT therapy, pre-stroke mRS >2, lacunar stroke subtype, unusual stroke etiology, baseline NIHSS >25 and onset-to-treatment (OTT) > 400 minutes. We determined the risk-adjusted probability [adjustment variables: age, NIHSS, OTT, pre-morbid mRS, hypertension, dyslipidemia, diabetes, AF, OCSP classification and etiology] of achieving functional independence at 3 months (mRS <=2) and performed subgroup analyses. Results: 1149 patients underwent IVT and 129 (10.1%) EVT. Patients in the EVT arm were younger (71.2+/-11.5 vs. 74.3+/-11.9), had higher NIHSS scores (18 [12-20] vs. 11 [7-18]), were treated later (198 [150-270] vs. 140 [105-190]) and more frequently had concomitant AF (55% vs. 21.9%), heart failure (12.4% vs. 4.9%), and were on anticoagulants (49.6% vs. 5.4%). Dyslipidemia (45.4% vs. 36.4%) and antiplatelets (42.7% vs. 26.4%) were more frequent in the IVT arm. Overall, the risk-adjusted likelihood of good functional outcome was better for EVT (OR: 1.56; 95% CI: 0.97-2.52). Subgroup analyses showed that patients with NIHSS =>14 (OR: 1.92; 95% CI: 1.10-3.46) and those treated within 180-270 minutes post-stroke (OR: 3.44; 95% CI: 1.41-8.39) benefited more from EVT. Conclusions: In a population-based study of reperfusion therapies for AIS, patients undergoing isolated EVT were more likely to achieve functional independence at 3 months as compared to patients treated with IVT, particularly those with severe strokes or those treated within 3-4.5 hours post-stroke. These findings need to be confirmed in a RCT.