Paradoxical sparing of cerebral circulation in massive TAVR-associated endocarditis

Prosthetic valve endocarditis (PVE) after transcatheter aortic valve replacement (TAVR) is an uncommon but life-threatening complication associated with high embolic risk.

A 82-year-old woman with prior TAVR presented with fever and malaise and was diagnosed with PVE due to Streptococcus Mutans. Transesophageal echocardiography revealed a large, highly mobile vegetation attached to the transcatheter valve, floating in the systolic jet of blood flow. Computed tomography demonstrated progressive splenic infarction and embolic involvement of the kidneys and mesenteric circulation, while no cerebral embolization occurred. At surgery, the previously visualized vegetation was no longer present, suggesting interval embolization. The transcatheter valve was explanted using cardiopulmonary bypass and cardioplegia. Radical debridement and annular enlargement with bovine pericardium were performed, followed by implantation of a surgical bioprosthesis using infection-conscious techniques. The patient recovered uneventfully. Post hoc analysis may suggest that proximal origin of the supra-aortic vessels (type III aortic arch configuration with the innominate artery originates below the horizontal plane of the inner curvature of the aortic arch) in the setting of an elongated aorta in this patient may explain the absence of cerebral embolization. This could possibly be relevant in combination with the centrally located floating vegetation, which was ejected along the strong central flow stream and consequently embolized to the abdominal organs. However, this excludes a generalization of the statement, and therefore the classic surgical principle of early surgery in patients with huge floating vegetations should be applied in similar cases.

This case illustrates the embolic potential of large, mobile vegetations in TAVR-associated endocarditis and supports early surgical intervention in accordance with both American and European infective endocarditis guidelines. The absence of cerebral embolization in the presence of massive systemic emboli should not be mistaken for anatomical protection.