1-038 Aortic root abscess in prosthetic valve endocarditis: a case report

Background Aortic root abscess formation is amongst the most serious complications of Infective Endocarditis (IE). Over the past two decades, the incidence of IE in Europe has doubled. The presence of a prosthetic valve significantly increases the risk of developing IE. In addition to the increased risk of developing IE, prosthetic valves also predispose patients to complications, most notably aortic root abscesses. Whilst the overall mortality rate in uncomplicated IE is relatively low, the presence of an aortic root abscess almost doubles this. This increased risk of mortality is primarily due to the susceptibility of an aortic root abscess to rupture and spread within the aorta and surrounding structures. Hence, radical treatment through surgical intervention is recommended in such cases to reduce morbidity and mortality. Case Report A 77-year-old man with an extensive past medical history, including a recent aortic valve replacement and discitis infection, presented with a fall to ED on the background of feeling generally unwell, muscle weakness and vomiting for the past 2 weeks. He had blood cultures that were persistently positive for staphylococcus epidermidis. Initial transoesophageal echocardiogram (TTE) showed an LVEF > 65%. Cardiac PET showed intense activity throughout the aortic valve replacement, as well as diffuse homogenous activity throughout the thoracolumbar spine, thus representing ongoing infection. A CT cardiac coronary angiogram was performed, which confirmed the presence of an aortic root abscess (See figure 1). Given the patient's preserved valve function, our Infective Endocarditis (IE) MDT meeting recommended urgent surgical intervention of the aortic valve and root repair, which the patient had successfully. Post-operatively, the patient had a single-chamber pacemaker fitted, and a repeat TTE was performed which concluded that the LV systolic function appeared well preserved and that the aortic root appeared dilated, with the valve having a peak gradient of 20.4 mmHg. Another IE MDT meeting was held, and it was concluded that no growth was found on the aortic valve post-operatively; thus, the patient would be started on a dual antibiotic course for 8 weeks. Discussion Aortic root abscess is a severe complication of infective endocarditis (IE), particularly in patients with prosthetic valves, which pose a higher risk due to their susceptibility to microbial colonisation. This case highlights the diagnostic challenge posed by non-specific symptoms such as malaise and vomiting, which can obscure the underlying infection. Persistent Staphylococcus epidermidis bacteremia, a common culprit in prosthetic valve infections, was a key diagnostic clue. While initial transthoracic echocardiography (TTE) showed preserved ventricular function, multimodal imaging, including PET and CT coronary angiography, proved crucial in identifying the aortic root abscess. This underscores the importance of combining imaging modalities to detect complex IE complications when standard investigations are inconclusive. Prompt surgical intervention was critical in preventing catastrophic outcomes such as abscess rupture and uncontrolled sepsis. The patient's development of complete heart block—a recognised complication of aortic root abscess—necessitated pacemaker insertion and highlighted the condition's impact on the cardiac conduction system. Renal impairment further complicated the case, emphasising the need for vigilant monitoring in patients with multiple risk factors. This case underscores key lessons: early diagnosis in high-risk patients, the value of multimodal imaging, and the essential role of multidisciplinary team (MDT) management in guiding treatment decisions and improving outcomes.