Undiagnosed Subacute Bioprosthetic Aortic Valve Abscess Leading to Complete Heart Block Requiring Permanent Pacemaker Insertion: A Case Report

Aortic root abscess is a rare and serious complication of infective endocarditis (IE). The presentation can be vague, and a high degree of suspicion is usually required. We present the case of a 78-year-old woman with a previous history of aortic valve replacement (AVR) surgery eight months ago who presented to the Accident and Emergency (A&E) department after falling at home. After initial scrutiny, her electrocardiogram (ECG) showed complete heart block, for which she received a dual-chamber permanent pacemaker. At that time, due to suspected chest infection, her laboratory tests showed slightly elevated C-reactive protein levels, but blood cultures and chest radiography did not show any evidence of infection. She was administered oral antibiotics for a chest infection and underwent successful pacemaker implantation. After approximately a week, she presented again with generalized weakness and collapse without loss of consciousness. Repeated blood tests showed elevated inflammatory markers, and blood cultures were positive for Streptococcus anginosus; therefore, intravenous antibiotics were administered. Transesophageal echocardiography (TEE) revealed an aortic root abscess, and ECG revealed a normal sinus rhythm. She also underwent pacemaker interrogation, which revealed normal pacemaker function. She also had a recent overseas travel history and required intensive care admission for a chest infection approximately two months ago, and she had been feeling generally unwell since then. The patient underwent tissue AVR (TAVR) for degenerative calcific aortic stenosis (AS) without periprocedural complications and recovered well after surgery. She was discussed in a multidisciplinary team meeting and was referred for early redo AVR. Unfortunately, the patient died during admission due to sepsis prior to undergoing redo valve surgery.