GROUP B STREPTOCOCCUS AGALACTIAE INFECTIVE ENDOCARDITIS COMPLICATED BY AORTO-CAVITARY FISTULA IN A POSTPARTUM FEMALE

Abstract

SESSION TITLE: Medical Student/Resident Cardiothoracic Surgery Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Infective Endocarditis (IE) can have many devastating complications and it is prudent to keep in mind even the rarest of sequela, including aorto-cavitary fistula (ACF). The following case describes an ACF, masked as tricuspid regurgitation, in the setting of native valve IE. The pathogen was Group B streptococcus (GBS) agalactiae, an uncommon culprit, but noteworthy given recent pregnancy. CASE PRESENTATION: A 34-year-old female, postpartum 10 months, was evaluated for 3 weeks of intermittent fevers, chills and dyspnea. Labs were unremarkable, but examination revealed a murmur. A transthoracic echocardiogram (TTE) showed severe aortic regurgitation (AR) with vegetation. At the cardiologist’s office, she endorsed presyncope and had a wide pulse pressure with a loud systolic murmur throughout the precordium and right upper sternum diastolic murmur. Bedside TTE in the ED showed additional severe tricuspid regurgitation. Cardiothoracic surgery was immediately consulted and she was quickly triaged to the ICU. Initial labs showed elevated lactate (19) with acute liver and renal failure. Continuous veno-venous hemodialysis and broad-spectrum antibiotics were started. She developed bradycardia with new left bundle branch block requiring pressors. Swan ganz catheter showed cardiac output of 7-8 L/min with an oxygenation step up in right atrium (68%) to pulmonary artery (90%), suggestive of ACF. Intraoperative transesophageal echo exposed a large aortic to right atria fistula, severe AR with vegetation and a normal tricuspid valve. She underwent aortic valve replacement, ACF repair, coronary artery bypass and intra-aortic balloon pump placement. Central venoarterial extracorporeal membrane oxygenation was initiated, however it was complicated by persistent thrombosis of the arterial cannula and the patient expired. Blood cultures, aortic and tricuspid valve tissue samples grew GBS agalactiae. DISCUSSION: ACF in IE occurs more readily in prosthetic valves IE versus native with an in-hospital mortality of roughly 40%. The primary culprit is classically coagulase negative staphylococcus and staphylococcus aureus. GBS is much less common, but can be a normal part of vaginal and rectal flora with colonization in 10-30% of pregnancies. GBS bacteremia is highly prevalent during pregnancy and can remain present in up to one third of patients 6 weeks postpartum. It is unclear if bacterial translocation during the birthing process may have resulted in bacteremia and sub-acute IE. CONCLUSIONS: Streptococcus agalactiae is an uncommon pathogen in infective endocarditis associated with high mortality and morbidity and even more ominous when coupled with an aorto-right atrial fistula. The result of this combination was an extremely critical and complex patient presentation that demanded emergent multidisciplinary attention. Reference #1: Ignasi Anguera et al, Aorto-cavitary Fistula in Endocarditis Working Group, Aorto-cavitary fistulous tract formation in infective endocarditis: European Heart Journal, Volume 26, Issue 3, February 2005, Pages 288–297. Reference #2: Patras, Kathryn A, and Victor Nizet. “Group B Streptococcal Maternal Colonization and Neonatal Disease: Molecular Mechanisms and Preventative Approaches.” Frontiers in pediatrics vol. 6 27. 22 Feb. 2018. Reference #3: Muller AE, Oostvogel PM, Steegers EA, Dorr PJ. Morbidity related to maternal group B streptococcal infections. Acta Obstet Gynecol Scand (2006) 85(9):1027–37. DISCLOSURES: No relevant relationships by Fastina Khan, source=Web Response No relevant relationships by Michaela Murphy, source=Web Response No relevant relationships by Sarah Upson, source=Web Response