Aims: This study evaluates three-dimensional (3-D) reconstruction of the coronary arteries in assessment of angiographically borderline lesions.
Methods and results: Three-dimensional (3-D) quantitative coronary angiography (QCA) was performed for 41 intermediate coronary stenotic lesions (IL) in 31 patients. Measurements of cross-sectional stenosis (CSS), diameter stenosis (DS) and plaque volume (PV) were correlated with the fractional flow reserve (FFR) values measured with a commercially-available pressure guide-wire. FFR <0.75 was considered significant. Using FFR, only 9/41 lesions appeared haemodynamically significant (FFR <0.75). When compared to lesions with an FFR >0.75, these lesions had higher CSS (65.3±9.4% vs. 44.7±10.6%, p=0.0001), higher DS (48±5.7% vs. 32.5±9.9%, p=0.0001), and higher PV (41.6±7.6% vs. 29.4±6.7%, p=0.0005), as measured by 3-D QCA. Regression analysis showed significant correlations between FFR and CSS (r=-0.481, p=0.001) and PV (r=-0.443, p=0.004), and a modest correlation between FFR and DS (r=-0,320, p=0.041). Compared with FFR, a CSS of 57% had the highest sensitivity and specificity (88.9% and 87.5%, respectively) for determining significant IL. Multivariate analysis showed 3-D-determined CSS to better predict FFR compared to the other measured variables (p=0.012).
Conclusions: Parameters obtained by 3-D QCA showed a significant correlation with FFR values. A cross-sectional stenosis >57% obtained by 3-D QCA has a high degree of sensitivity and specificity to detect a haemodynamically significant intermediate coronary stenosis.