A clot-in-transit: an imminent threat

SESSION TITLE: Pulmonary Vascular Disease Case Report Posters 6 SESSION TYPE: Case Report Posters PRESENTED ON: 10/10/2023 09:40 am - 10:25 am INTRODUCTION: A clot in transit (CIT) is a mobile thrombus arising from the deep veins that is freely floating in the right heart. Although rare, a CIT is the most feared complication of deep vein thrombosis, and often indicates that pulmonary embolism (PE) is imminent unless promptly treated. The mortality rate in these clinical situations is reported to be 20 to 45%, although is often underdiagnosed. We present a case of CIT with PE complicated by thrombocytopenia which hindered therapeutic approach. CASE PRESENTATION: An 82-year-old female with history of hypertension and diabetes mellitus presented with complaints of right upper quadrant abdominal pain and generalized weakness. Vital signs were stable on arrival with an oxygen saturation of 98% on ambient air. Pertinent bloodwork included platelet count of 92,000 cells/µL, troponin I level 0.113 ng/mL, and pro-brain natriuretic peptide was 7,880 pg/mL. The electrocardiogram (ECG) showed T wave inversion in leads V1-V3, raising suspicion for PE with right ventricular (RV) strain. Transthoracic echocardiogram (TTE) showed a large, mobile thrombus in the right atrium (RA) with a right ventricular systolic pressure (RVSP) of 52 mmHg (Figure 1). Computed tomography pulmonary angiogram (CTA) revealed multiple filling defects within the bilateral main pulmonary arteries and RV dilation representing acute pulmonary embolism with right heart strain. Lower extremity dopplers confirmed deep vein thrombosis in the right femoral vein. Given her significant clot burden and RV strain, interventional radiology was consulted. However, due to difficult anatomy she was not a candidate for thrombectomy, and instead underwent bilateral catheter-directed thrombolysis (CDT). Post-procedure she became hypotensive and acidotic requiring mechanical ventilation, vasopressor, and inotropic support. However, four hours later, the patient suffered a pulseless electrical activity cardiac arrest and unfortunately expired. DISCUSSION: CIT is a rare phenomenon that often precedes acute PE and is associated with an increased mortality rate and poor prognosis compared to PE alone. Due to the increasing use of point of care ultrasound (POCUS) in the critically-ill population, the diagnosis of right heart thrombus has become more prevalent. Currently, precise guidelines including anticoagulation, systemic thrombolysis, CDT, thrombectomy or embolectomy directing the treatment of PE with concomitant CIT do not exist. This supports the importance of creating an individualized and multidisciplinary approach when managing a CIT with PE. We opted for CDT due to her profound thrombocytopenia, tortuous anatomy, presence of RV strain, and significant clot burden that predisposed her to circulatory collapse. CONCLUSIONS: Despite the unfavorable outcome in our aforementioned case, recent studies suggest that the use of thrombolytics have shown improved outcomes and a safer therapeutic profile when compared to surgical embolectomy or anticoagulation alone. However, the optimal therapeutic approach remains unclear. It is imperative to risk stratify patients based on age, presence of RV strain, comorbidities, hemodynamics, and overall prognosis in order to provide individualized management for improved chance at survival. REFERENCE #1: Rose et al. Treatment of right heart thromboemboli. Chest. 2002;121(3):806-14. REFERENCE #2: Burgos et al. Floating right heart thrombi: A pooled analysis of cases reported over the past 10 years. Am J Emerg Med. 2018 Jun; 36(6): 911-915. REFERENCE #3: Koć M et al. Outcome of patients with right heart thrombi: the Right Heart Thrombi European Registry. ERJ. 2016;47(3):869-75. DISCLOSURES: No relevant relationships by Christian Almanzar Zorrilla No relevant relationships by Vincent DeGregory No relevant relationships by Daniel Heller No relevant relationships by Ana Martinez Nunez No relevant relationships by Dionne Morgan No relevant relationships by Shany Quevedo No relevant relationships by Lyanne Rolon