Aspergillus Endocarditis: A Rare but Serious Complication During Treatment With Ibrutinib

Background: Aspergillus endocarditis (AE) is a rare but life‐threatening form of infective endocarditis, accounting for only 0.2% of cases. Despite antifungal and surgical treatment, AE remains a major diagnostic and therapeutic challenge with high mortality rates. Ibrutinib, a Bruton’s tyrosine kinase inhibitor used in the treatment of chronic lymphocytic leukemia (CLL), has been associated with early‐onset invasive aspergillosis. However, no cases of AE have been documented in patients undergoing ibrutinib therapy to date. Case Presentation: A 71‐year‐old man with relapsed CLL on third‐line ibrutinib therapy and a history of arrhythmic cardiomyopathy requiring an implantable cardioverter‐defibrillator (ICD) presented with a six‐month history of fever, cough, and fatigue. On admission, a full‐body computed tomography scan revealed intestinal ischemia and multiple thrombotic occlusions involving the kidney, spleen, and iliac artery. Markedly elevated beta‐D‐glucan and serum galactomannan levels prompted empirical initiation of isavuconazole. Transthoracic echocardiography identified a large vegetation (2.5 × 4 cm) on the mitral valve with ICD lead involvement. Despite urgent surgical intervention—including ICD extraction and mitral valve replacement—the patient succumbed to complications. Intraoperative valve cultures grew Aspergillus fumigatus. Conclusions: This report underscores the severity of AE despite combined surgical and antifungal therapy. Given its high mortality rates, clinicians should maintain a high index of suspicion for AE, particularly in immunocompromised patients or those with a history of cardiac surgery or implanted cardiac devices. Early recognition and aggressive intervention remain essential to improving outcomes.