Aortic Root Abscess Secondary to Coxiella burnetii Following TAVR

BACKGROUND: Q fever endocarditis, caused by the intracellular pathogen Coxiella burnetii, is uncommon yet highly destructive. Patients typically present with negative blood cultures and vague symptoms that delay diagnosis. CASE SUMMARY: A 67-year-old man with significant cardiovascular comorbidities, including prior transcatheter aortic valve replacement, permanent pacemaker, and reduced ejection fraction, presented with chest pain. Imaging revealed an aortic root abscess extending to the anterior mitral leaflet. Although blood cultures were negative, molecular diagnostics (Karius testing) and serology confirmed C burnetii. Surgical treatment required a complex hemi-Commando procedure, including radical debridement, aortic root homograft replacement, and reconstruction of the aorto-mitral curtain. Prolonged antibiotic therapy (doxycycline, hydroxychloroquine) was initiated for 2 years. Postoperatively, the patient's condition stabilized with clinical improvement. DISCUSSION: This case highlights the destructive nature of Q fever endocarditis and emphasizes the importance of prompt diagnosis, multidisciplinary management, and aggressive surgical intervention in patients with extensive structural damage. TAKE-HOME MESSAGES: Q fever endocarditis is rare but destructive, necessitating high clinical suspicion despite negative blood cultures and advanced molecular diagnostics for diagnosis. Extensive surgical intervention, such as the Commando procedure, combined with multidisciplinary collaboration, significantly improves outcomes in severe cardiac involvement.