Determination of Optimal Fluoroscopic Angulations for Left Main Coronary Artery Ostial Interventions: 3-Dimensional Computed Tomography Validation

BACKGROUND: Current recommendations for the best views for the left main coronary artery (LMCA) ostium intervention are empirical. OBJECTIVES: To determine the optimal projection to visualize the LMCA ostium using only fluoroscopy. METHODS: The optimal projection to visualize the LMCA ostium was determined using fluoroscopic images of superimposing the lowest points of the distal ends of two J tipped wires in the noncoronary cusp (NCC) and right coronary cusp (RCC). This was validated independently using 3-dimensional computed tomography (3D-CT) reconstruction. RESULTS: Satisfactory images of the overlapping wires in NCC and RCC could be obtained in 90% (45/50). Between the fluoroscopic and the 3D-CT reconstruction approaches, the mean difference for NCC and RCC overlapping at horizontal axes is -1.8 with a 95% limit of agreement between −3.94 and 0.34 (p=0.10) and at vertical axes −1.6 with a 95% limit of agreement between −3.46 and 0.26 (p=0.09); and the mean difference for the optimal projection to visualize the LMCA ostium at horizontal axes is −3.22 with a 95% limit of agreement between -7.26 and 0.81 (p=0.11) and at vertical axes −2.31 with a 95% limit of agreement between −5.83 and 1.21 (p=0.09). The 3D angulation deviation for the optimal projection to visualize the LMCA ostium was 8.5° ± 4.7° when the LMCA ostium faced the NCC-RCC commissure (n = 32) and 22.3° ± 16.0° (p=0.009) when it did not (n = 13). CONCLUSIONS: The optimal projection for LMCA ostial intervention can be determined using fluoroscopic images of superimposing wires in the NCC and RCC when the LMCA ostium faces the NCC-RCC commissure, as was the case in 71% of the patients studied.