Comparison of frequency domain optical coherence tomography and quantitative coronary angiography for the assessment of coronary lesions

Quantitative coronary angiography (QCA) has been used as a standard technique for the evaluation of coronary artery disease for many years. Intracoronary optical coherence tomography (OCT) offers higher resolution, faster image acquisition speeds and greater sensitivity than the intravascular ultrasound (IVUS). Recently developed frequency domain OCT (FD-OCT) systems overcome many technical limitations of conventional time domain OCT systems (TD-OCT). The main objective of this study was to compare the FD-OCT and QCA measurements for the assessment of coronary lesions. A total of 21 stenoses in 18 patients were analysed using QCA and FD-OCT. The average minimum lumen diameter (MLD) and percent lumen area stenosis (%AS) by QCA were 1.52 +/- 0.44 mm and 68 +/- 9% respectively. The average MLD and % AS by FD-OCT were 1.32 +/- 0.38 mm and 63 +/- 14% respectively. There was a moderate but significant correlation between QCA and FD-OCT measured MLD (r = 0.5, p < 0.01) and % AS (r = 0.56, p < 0.01). Bland-Altman analysis showed that the mean differences between the QCA and FD-OCT measurements were 0.18 +/- 0.81 (limits of agreement: -0.63 to 0.99) for MLD and 4.4 +/- 22.8 (limits of agreement: -18.4 to 27.2) for % AS. The root mean square error (RMSE) between the QCA and FD-OCT measured MLD and % AS was +/- 0.44 mm and +/- 12.1% respectively.