P569Outcomes of catheter-directed thrombolysis versus standard medical therapy in patients admitted to intensive care units with acute pulmonary embolism

Abstract

Background: Acute pulmonary embolism (PE) is a life-threatening disease, leading to both short and long term morbidity and mortality. Standard therapy for PE is systemic anticoagulation, with systemic thrombolysis (ST) reserved for hemodynamically unstable patients (massive PE). Studies have shown that catheter- directed thrombolysis (CDL) with low dose thrombolytics leads to faster resolution of right ventricular strain in submassive PE; however, the impact of CDL on clinical outcomes remains unclear. Purpose: We investigated the outcomes of consecutive patients with PE as the primary diagnosis admitted to intensive care units (ICU) who underwent CDL as compared to systemic anticoagulation. Methods: This was an observational study of all patients with PE admitted to an ICU within our health system between June 2014 and April 2016. Massive PE was defined by need for intravenous vasopressor support, and submassive PE by having right ventricular strain (defined as RV: LV ratio ≥1 on CT angiography) but not on vasopressors. All other PEs were considered low risk. Treatment groups were medical therapy (MT) group (systemic anticoagulation) and CDL group (catheter-based delivery of tPA). Outcomes were 30 day and 1 year mortality, 30 day and one year readmission rates, need for transfusion, and rate of intracerebral hemorrhage. CDL patients were matched to MT controls using a propensity-score matching algorithm based on PE severity index (PESI) score, history of malignancy, and PE risk category. Survival was compared between groups using Kaplan-Meier curves and Cox proportional-hazards models. Results: Of the 480 patients who were included in the study, 149 (31%) had low risk PE (145 received MT, 4 received CDL), 235 (49%) patients with submassive PE (137 receiving MT, 98 receiving CDL), and 33 (6.9%) patients had massive PE (27 received MT, 6 received CDL). Unadjusted mortality rates were 4.3% for CDL vs 20% for MT at 30 days and 10.3% for CDL vs 31.5% for MT at 1 year (HR 0.27, 95% CI 0.15-0.47, p<0.001). In the propensity-matched cohort (115 CDL patients matched to 115 similar MT controls), mortality rates were 4.3% for CDL vs 7.8% for MT at 30 days and 10.4% for CDL vs 16.7% for MT at 1 year (HR 0.48, 95% CI 0.25-0.91, p=0.025); Figure 1. Length of stay was significantly shorter in the CDL group. The readmission and index admission bleeding rates were not statistically different between both groups. Conclusions: In patients presenting with acute PE, the group treated with CDL experienced reduced mortality at 30 days and 1 year when compared to MT. Further randomized studies are required to confirm the causality of these findings.