Invasive Right Anomalous Coronary Arteries Assessment

In the right anomalous aortic origin of a coronary artery (R-AAOCA), invasive fractional flow reserve during dobutamine (FFR Dobutamine ) allows to assess dynamic interarterial/intramural compression that may lead to ischemia. However, FFR Dobutamine requires expertise and is procedurally complex. Therefore, a simpler alternative is needed, but it remains uncertain whether routine intravascular ultrasound (IVUS) and standard FFR during adenosine (FFR Adenosine ) can reliably determine hemodynamic relevance. This study aimed to compare the diagnostic accuracy of FFR Adenosine and IVUS-based minimal lumen area (IVUS-MLA) against the reference standard of FFR Dobutamine for identifying hemodynamically relevant R-AAOCA. Consecutive patients of a single center were prospectively enrolled over 5 years (June 2020-June 2025) with R-AAOCA and interarterial/intramural course. All patients underwent FFR Dobutamine , FFR Adenosine , and resting IVUS-MLA of the proximal anomalous segment. Hemodynamically relevant R-AAOCA was defined as FFR Dobutamine ≤0.80. Diagnostic performance was assessed using receiver-operating characteristic analysis. A total of 73 patients (mean age 51 ± 13 years; 34% female) were included. Seventeen patients (23%) had hemodynamically relevant R-AAOCA. FFR Adenosine ≤0.80 predicted FFR Dobutamine ≤0.80 with 100% specificity and positive predictive value, 29% sensitivity and 82% negative predictive value (area under the curve: 0.81). IVUS-MLA ≤5.5 mm 2 predicted hemodynamic relevance with 100% sensitivity and negative predictive value, 68% specificity, and 49% positive predictive value (area under the curve: 0.88). In adults with newly diagnosed R-AAOCA and interarterial and intramural course, one-quarter were hemodynamically relevant. FFR Adenosine could reliably rule-in, while IVUS-MLA could effectively rule-out relevant R-AAOCA, potentially reducing the need for FFR Dobutamine testing.