Discrepancies in vessel sizing between angiography and intravascular ultrasound varies according to the vessel evaluated

Abstract

Quantitative coronary analysis (QCA) of the coronary artery and stent size may be influenced by anatomical location in relation to both calibration point and the X-ray tube. The impact of this phenomenon on lesion assessment is undetermined. In total, 427 consecutive patients who underwent PCI with intravascular ultrasound (IVUS)-guidance were enrolled. The minimum stent diameter (MSD) was measured using QCA (MSDQCA) and IVUS (MSDIVUS) analysis. We used reference objects positioned at a different height from the X-ray source to validate our approach. A statistically positive moderate correlation was observed between MSDQCA and MSDIVUS (r=0.649, p=0.001). The mean MSDQCA and MSDIVUS were 3.04±0.49 mm and 2.68±0.47 mm respectively. The difference between MSDQCA and MSDIVUS of >0.75 mm was more frequently observed in the LCx rather than in the LAD (7.4% in the LAD vs. 24.3% in the LCx, p=0.001). The discrepancy between the MSDQCA and MSDIVUS for the LCx was larger than for the LAD, and tended to be larger than for the RCA (13.3% vs. 18.5%, p=0.05 and 18.5% vs. 14.5%, p=0.17). A discrepancy >20% was more frequently observed in the small (≤2.5 mm) than in the large MSDIVUS group (52.7% vs. 25.1%, p=0.001). This discrepancy was more common in the LCx than in the LAD or RCA (48.6% vs. 30.9% vs. 31.2%, p=0.03). Assessment of the MSDQCA is more likely to overestimate in the LCx than in the LAD, particularly when the MSDIVUS is <2.5 mm. Therefore, we should be less aggressive in oversizing balloons and stents based on QCA for the LCx or small vessel intervention.