FUO and negative blood culture results: Is transthoracic echocardiography sufficient to exclude infective endocarditis?

Margarita Brida, MD, is an assistant professor at the University of Rijeka, Croatia, and consultant cardiologist at the Royal Brompton Hospital, UK. She is a chairperson elect of the European Society of Cardiology (ESC) Working Group on adult congenital heart disease (2024-2026) and associate editor for adult congenital heart disease in the European Heart Journal and deputy editor of the International Journal of Cardiology Congenital Heart Disease. Her current work is focused on the development of adult congenital heart disease in the South Eastern European region, and her main fields of interest are echocardiography and heart failure in adult congenital heart disease.

Is transthoracic echocardiography sufficient to exclude infective endocarditis in a patient with fever of unknown origin (FUO) and negative blood culture results? Can a patient with infective endocarditis have normal echocardiography results?

Thank you for this question. I would answer very shortly: absolutely not. Transthoracic echo is not sufficient. If we have a high level of suspicion for infective endocarditis, we need to be proactive and look further.

The first modality that should be done is transesophageal echocardiography. And if we still have a high level of suspicion and we have findings that we are not certain how to interpret, we should look into other imaging modalities. It's very important to diagnose infective endocarditis in good time to start the treatment also in good time.