Case report: life-threatening endocarditis in an adult with repaired congenital heart disease lost to follow-up.

Background: Adults with repaired congenital heart disease remain vulnerable to complications such as valvular dysfunction, aortic dissection, and infective endocarditis. Loss to specialist follow-up and incomplete synthesis of early warning signs can delay diagnosis. This abstract highlights how such factors combined to produce a near-fatal presentation of endocarditis. Case summary: A 58-year-old man with childhood repair of aortic coarctation, otherwise previously healthy, presented 1 week after a dental filling without antibiotic prophylaxis. He developed fever, back pain, and hypoxia. Treated initially for pneumonia, he failed to improve. Progressively abnormal conduction, embolic renal lesions, and refractory sepsis eventually prompted echocardiography, which revealed a severely calcified bicuspid aortic valve with large vegetations and an ascending aortic abscess. He underwent emergency valve replacement and aortic root patch repair, followed by prolonged intravenous antibiotics and implantation of cardiac resynchronization therapy. Discussion: This case underscores three system-level failures that nearly proved fatal: loss to follow-up during the paediatric-to-adult transition, dismissal of a solitary positive blood culture, and incomplete synthesis of multisystem 'red flags'. Vigilant lifelong surveillance in adults with congenital heart disease, coupled with a low threshold for endocarditis work-up, including a point-of-care ultrasound in the acute setting in septic patients with structural heart lesions, is essential to improve outcomes, as well as appropriate dental prophylaxis in criteria-met adult congenital heart disease patients.