Background: Significant aorto-ostial disease is difficult to evaluate with angiography and sometimes even with intravascular ultrasound (IVUS).
Methods: We used IVUS to compare ostial lesions in the left main coronary (LMCA, n = 45) versus the right coronary artery (RCA, n = 50). IVUS measurements were performed each 1 mm beginning within the ostium and continuing to the distal reference segment. Negative remodeling was defined as a remodeling index (lesion/distal reference arterial area) < 0.95.
Results: Patient age was 66 +/- 11 years in the LMCA group and 66 +/- 11 years in the RCA group; 56% of the LMCA ostial lesions and 46% of RCA ostial lesions were in males, and 35% of the LMCA ostial lesions and 20% of the RCA ostial lesions were in diabetics. With the exception of a smaller minimum lumen area (p < 0.0001) and distal reference plaque burden (p = 0.002) in ostial RCA lesions and a larger eccentricity index in ostial LMCA lesions (p = 0.001), both sites were remarkably similar. Both ostial LMCA and RCA lesions were short, had modest amounts of calcium, had modest plaque burdens, but had a marked frequency of negative remodeling (84% in LMCA and 86% in RCA; p = 1.0).
Conclusion: IVUS morphometry is similar in ostial LMCA and RCA lesions; negative remodeling is the dominant contributor to lumen compromise in both locations.