Thea Stybe, Lauge Østergaard, Amna Alhakak, Klaus Fuglsang Kofoed, Jørgen Tobias Kühl, Oskar Ward, Lars Køber, Sune Damgaard, Morten Smerup, Jesper James Linde, Emil Fosbøl
Detecting perivalvar infection including aortic root abscesses and pseudoaneurysms in infective endocarditis remains challenging, and standard transoesophageal echocardiography (TEE) often leaves diagnostic uncertainty. This study examines whether adding cardiac computed tomography (CCT) improves detection of such complications. 32 endocarditis cases who underwent TEE, CCT, and cardiac surgery were retrospectively analysed. Three expert cardiologists independently reviewed anonymised TEEs followed by corresponding CCTs. Diagnostic performance for detecting aortic root abscesses and pseudoaneurysms was assessed against surgical findings as gold standard. ROC curves and AUC compared the two modalities. 13/32 cases had abscess/pseudoaneurysms (8 abscesses, 8 pseudoaneurysms). Accuracy increased from 88% with TEE to 91% with TEE + CCT. Sensitivity improved from 85% to 100% while specificity decreased from 89% to 84%. CCT increased NPV to 100% and diagnostic confidence in 91% of cases. AUC tended higher for TEE + CCT than TEE alone (0.92 vs. 0.87, p = 0.47). For pseudoaneurysms, CCT increased AUC (TEE + CCT=0.98 vs. TEE = 0.67, p = 0.001). Adding CCT to TEE improved the detection and exclusion of abscess/pseudoaneurysms, although results should be interpreted cautiously due to the sample size. The combination increased sensitivity at the expense of a small reduction in specificity, achieved a NPV of 100% and increased diagnostic confidence in physicians, supporting CCT as complementary imaging. The greatest benefit was for pseudoaneurysms, where TEE + CCT identified all and significantly improved AUC, whereas the overall improvement was less pronounced when abscesses were included. Given the rarity of these complications and the limited sample size, larger prospective studies are warranted to confirm these findings.