IMPACT OF OBESITY ON TIME-TO-THERAPEUTIC HEPARIN IN ACUTE SUBMASSIVE PULMONARY EMBOLISM

Abstract

SESSION TITLE: Pulmonary Vascular Disease Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: Mortality increases in patients presenting with acute pulmonary embolism (PE)when time to therapeutic unfractionated heparin (UFH) exceeds 24 hours. Literature has demonstrated more than half of obese PE patients fail to achieve therapeutic aPTT levels with standard UFH nomograms likely due to a failure of dosing caps and suboptimal dosing. Obesity also increases the likelihood of venous thromboembolism (VTE). Our institution has employed a modified weight-based nomogram for our this population. This study aimed to examine the impact of obesity on achieving therapeutic anticoagulation and its subsequent impact on outcomes. METHODS: Patients with acute submassive PE who received IV UFH were included at our institution. Patients were divided based on body mass index (BMI) =30 kg/m2 and <30 kg/m2. Baseline characteristics were collected. Time to therapeutic aPTT (goal 55-90 sec) was collected per our institution’s nomogram. We also obtained data on administration of heparin bolus, starting dose of heparin, heparin dose at therapeutic aPTT, and time to heparin initiation. Clinical outcomes included: concurrent deep vein thrombosis (DVT), bleeding events utilizing GUSTO criteria, and mortality. RESULTS: A total of 130 patients were included. Of these, 67 were BMI =30 kg/m2 and 63 were BMI <30 kg/m2. Baseline characteristics were similar between groups with the exception of PESI score being higher in the non-obese group (109.6 +/- 42 vs. 135.8 +/- 49.7; p<0.01). There was no difference between groups in administration of heparin bolus (68.7% vs. 69.8%; p=0.67) or time to heparin initiation (22.3 +/- 42.7 vs. 40.1 +/- 90.5 hours; p=0.15). Obese patients received a lower weight-based dose (units/kg/hr) at heparin initiation (15.9 ? 3 vs. 17.9 ? 1.8; p<0.01) and received a lower dose once therapeutic aPTT achieved (15.9 +/- 3 vs. 17.9 +/- 1.8; p<0.01). Both groups achieved a therapeutic aPTT within 24 hours (83.6% vs. 77.8%; p=0.46) and no difference between groups in maintaining therapeutic aPTT (56.7% vs. 56.7%; p=0.68). There were more patients in the obese group that had a concomitant DVT (76.1% vs. 55.6%; p=0.02) but there was no difference in bleeding events among groups (6% vs. 15%; p=0.11). Mortality was higher in the non-obese population (17.9% vs. 38.1%; p=0.01). CONCLUSIONS: Our institutional modified weight-based nomogram led to achievement of therapeutic aPTT within 24 hours in the majority of patients regardless of obesity status. The obese population required lower weight-based doses of heparin to achieve therapeutic aPTTs with no difference in bleeding events. They did have a higher occurrence of concurrent DVTs. The non-obese population did have an increase mortality rate however these patients were more acute as reflected by higher PESI scores. CLINICAL IMPLICATIONS: Modified weight-based nomograms can ensure obese patients achieve therapeutic aPTTs within the optimal 24 hours. DISCLOSURES: No relevant relationships by Sorcha Allen, source=Web Response No relevant relationships by Nathalie Antonios, source=Web Response No relevant relationships by Yevgeniy Brailovsky, source=Web Response No relevant relationships by Lucas Chan, source=Web Response No relevant relationships by Ibrahim Chowdhury, source=Web Response No relevant relationships by Amir Darki, source=Web Response No relevant relationships by Jawed Fareed, source=Web Response No relevant relationships by Jeremiah Haines, source=Web Response No relevant relationships by Shannon Kuhrau, source=Web Response No relevant relationships by Ahmad Manshad, source=Web Response No relevant relationships by Alexandru Marginean, source=Web Response No relevant relationships by Dalila Masic, source=Web Response No relevant relationships by Karim Merchant, source=Web Response No relevant relationships by Stephen Morris, source=Web Response No relevant relationships by Katerina Porcaro, source=Web Response