STUCK IN TRANSIT: LOOMING DISASTER IN A PATIENT WITH A PATENT FORAMEN OVALE-ADHERENT THROMBUS

Abstract

SESSION TITLE: Pulmonary Vascular Disease SESSION TYPE: Med Student/Res Case Report PRESENTED ON: 10/23/2019 8:45 AM - 9:45 AM INTRODUCTION: The diagnosis of an impending paradoxical embolism, defined as a thrombus adherent to a patent foramen ovale (PFO), is very rare with the first reported case in 1985 [1]. This phenomenon is increasingly diagnosed due to improved availability of echocardiography and advances in imaging technology, although fewer than 200 cases to date have been reported [2,3]. Impending paradoxical embolism carries a high 30-day mortality rate of 18.4-29% [3,4]. CASE PRESENTATION: Our patient is a 64-year-old male with tobacco use, former alcohol and methamphetamine abuse, who presents with 1-month of progressive exertional dyspnea, lower extremity swelling, and 1-week of left-sided pleuritic chest pain. He was tachycardic and tachypneic on admission, with a blood pressure of 111/78 and SpO2 of 89% on room air. Significant laboratory values include a BNP of 1937 (5-99), troponin 0.03 (<0.03), and an EKG showing sinus tachycardia and right axis deviation. Admission transthoracic echocardiogram (TTE) revealed a reduced left ventricular ejection fraction of 20-25% with global hypokinesis, a moderately dilated right ventricle with severely reduced systolic function, elevated estimated pulmonary artery systolic pressure (PASP) of 63-73 mmHg, and a mobile mass in the right atrium (RA). A CT chest angiogram showed extensive chronic/subacute-appearing thrombi involving the main pulmonary arteries with extension into the right and left lower lobe segmental branches, and a 4.6 cm heterogeneous RA mass. A transesophageal echocardiogram showed a 4.1 x 4.5 cm RA mass traversing a newly noted PFO. Lower extremity dopplers showed bilateral deep venous thromboses extending from the iliac to popliteal veins. Coronary angiogram was without significant obstructive coronary artery disease. His treatment included a continuous heparin infusion, oxygen supplementation, and progressive diuresis. The patient was transferred to a tertiary referral center for pulmonary thromboendarterectomy with PFO closure. The removed mass from the pulmonary arteries was consistent with chronic clot and the final pathology of the atrial mass was organizing thrombus. DISCUSSION: Despite the increasing frequency of detection of an impending paradoxical embolism, the diagnosis is still rare and there are no established treatment guidelines. There is a trend towards improved outcomes with surgical endarterectomy over thrombolysis or anticoagulation alone [5]. CONCLUSIONS: Our patient underwent successful endarterectomy without evidence of systemic embolization. At 1-year follow up, he has normal cardiac function and normal PASP by TTE, with no perfusion abnormalities on VQ scan. His hypercoagulable work-up was non-diagnostic, although anticoagulation for life is recommended. Reference #1: 1. U. Nellessen, W. Daniel, G. Matheis, et al.Impending paradoxical embolism from atrial thrombus: correct diagnosis by transeosophageal echocardiography and prevention by surgery. J Am Coll Cardiol, 5 (1985), pp. 1002-1004. Reference #2: 2. Podroužková H, Horváth V, Hlinomaz O, et al. Embolus entrapped in patent foramen ovale: impending paradoxical embolism. The Annals Of Thoracic Surgery. 2014;98(6):e151-e152. https://doi.org/10.1016/j.athoracsur.2014.08.072. Reference #3: 3. Myers P. O., Bounameaux H., Panos A., Lerch R., Kalangos A. Impending paradoxical embolism: systematic review of prognostic factors and treatment. Chest. 2010;137(1):164–170. https://doi.org/10.1378/chest.09-0961. 4. Shepherd F, White-Stern A, Rahaman O, Kurian D, Simon K. Saddle Pulmonary Embolism with Thrombus in Transit across a Patent Foramen Ovale. Case Rep Cardiol. 2017;2017:6752709. 5. Fauveaua E., Cohen A., Bonnet N., Gacem K., Lardoux H. Surgical or medical treatment for thrombus straddling the patent foramen ovale: Impending paradoxical embolism? Report of four clinical cases and literature review. Archives of Cardiovascular Diseases. 2008;101(10):637–644. https://doi.org/10.1016/j.acvd.2008.08.011. DISCLOSURES: No relevant relationships by Jenifer Lentz, source=Web Response