Abstract WP110: Does Paradoxical Embolism Impart Different Outcomes After IVT Treatment?

Abstract

Introduction: There are pilot data indicating that patients with acute ischemic stroke (AIS) due to paradoxical embolism (PxE) via patent foramen ovale (PFO) may respond better to intravenous thrombolysis compared to other stroke subtypes. We sought to compare the safety and efficacy of IVT in AIS patients with and without PxE as their stroke etiopathogenic mechanism in a high-volume tertiary care stroke center. Methods: Consecutive AIS patients treated with IVT during a five-year period were evaluated. Baseline stroke severity and early hypodensity on baseline CT were assessed by NIHSS-score and ASPECTS by certified physicians. Presence of PFO was diagnosed by echocardiography, while PxE was determined using the TOAST criteria. Safety of IVT was evaluated using SITS-MOST sICH definition. Three-month functional status was assessed using modified Rankin Scale (mRS) scores. Results: Out of total 1301 IVT-treated AIS patients, we identified 51 cases (4%) with PxE due to PFO. Patients with PxE were younger (mean age 52±15 vs. 63±15 years; p<0.001), but had similar baseline and 24-hour NIHSS-scores compared to the others. The rates of sICH (4% vs. 5%), 3-month functional independence (mRS-scores 0-2; 77% vs. 68%) and 3-month favourable functional outcome (mRS-scores 0-1; 64% vs. 53%) did not differ (p>0.1) between the two groups. Three-month mortality was lower in the PxE group (0% vs. 9% by Fisher exact test). PxE due to PFO (OR computed using Firth’s penalized likelihood method for rare events: 0.11; 95%CI: 0.01-1.74) was not independently associated with 3-month mortality on multivariable logistic regression models adjusting for potential confounders. Conclusions: Our study indicates that AIS patients with PxE due to PFO have similar response to IVT compared to AIS patients with other underlying mechanisms.