Quantitative angiography and optical coherence tomography for the functional assessment of nonobstructive coronary stenoses: comparison with fractional flow reserve.

BACKGROUND: The purpose was to compare 3-dimensional quantitative coronary angiography (3D-QCA) with optical coherence tomography (OCT) for the functional assessment of nonobstructive coronary stenoses, as evaluated by fractional flow reserve (FFR). METHODS: Fifty-five nonobstructive coronary stenoses (30%-50% diameter stenosis by visual estimation) were assessed in 36 patients using FFR, 2-dimensional QCA (2D-QCA), 3D-QCA, and OCT. RESULTS: Angiographic stenosis severity by 2D-QCA was 34% \ub1 13% diameter stenosis, and minimal lumen diameter (MLD) was 1.77 \ub1 0.58 mm. Fractional flow reserve values were 0.85 \ub1 0.10. Correlation coefficients between FFR and MLD or minimal lumen area (MLA) were highly significant for both 2D- and 3D-QCA (all P 1.53 mm or MLA >2.43 mm(2) are unlikely to be hemodynamically significant. CONCLUSIONS: In nonobstructive coronary stenoses, anatomical parameters derived from 3D-QCA can best identify lesions with preserved FFR values