Mitral valve infective endocarditis in a dialysis patient with a tunneled dialysis catheter and prior MitraClip® implantation: an autopsy case

BACKGROUND: The number of patients with heart disease who can benefit from treatment is continuing to increase due to the widespread use of cardiac implantable devices. Accordingly, the number of cardiac device-related infective endocarditis (CDRIE) cases has been increasing year by year. We report a very rare experience of performing an autopsy on a patient who died of CDRIE at the site of MitraClip ® implantation, which has recently been developed as a treatment option for severe mitral regurgitation. In addition to hematoxylin–eosin (H-E) staining, Elastica-Masson staining in the present case revealed destruction of all of the atrial, trabecular, fiber and myocardial layers. CASE PRESENTATION: The patient was hemodialyzed with a dialysis catheter. Hemodialysis treatment was difficult due to functional mitral regurgitation caused by cardiac dysfunction, and the MitraClip® procedure was performed. However, he subsequently developed a fever and dialyzation became difficult again, and he was admitted to the cardiology department. Echocardiography revealed a large vegetation at the site of MitraClip® implantation and a diagnosis of CDRIE was made. Guidelines recommend removal of the device and surgical intervention. However, considering the patient's general condition, a decision was made at a heart team conference to give priority to antibiotic therapy. However, the patient did not respond to antibiotic therapy and died of septic shock. CONCLUSION: To our knowledge, this is the first reported case of CDRIE and death after MitraClip® implantation that resulted in an autopsy. Furthermore, not only H-E staining but also Elastica-Masson staining was performed, and it was confirmed that there was significant valve tissue destruction. In the future, the MitraClip® procedure, even though it is minimally invasive, should be carefully considered in immunocompromised patients.