Diagnostic Performance of Diastolic Hyperemia-Free Ratio Compared With Invasive Fractional Flow Reserve for Evaluation of Coronary Artery Disease.

Hyperemic and nonhyperemic pressure ratios are frequently used to assess the hemodynamic significance of coronary artery disease and to guide the need for myocardial revascularization. However, there are limited data on the diagnostic performance of the diastolic hyperemia-free ratio (DFR). We evaluated the diagnostic performance of the DFR compared with invasive fractional flow reserve (FFR). We performed a prospective, single-center study of 308 patients (343 lesions) who underwent DFR and FFR for evaluation of visually estimated 40% to 90% stenoses. Diagnostic performance of the DFR compared with FFR was evaluated using linear regression, Bland-Altman analysis, and receiver operating characteristic curves. The overall diagnostic accuracy of the DFR was 83%; the accuracy rates were 86%, 40%, and 95% when the DFR was <0.86, 0.88 to 0.90, and >0.93, respectively. The sensitivity, specificity, positive predicative value, and negative predictive value were 60%, 91%, 71%, and 87%, respectively. The Pearson correlation coefficient was 0.75 (p <0.05). The Bland-Altman analysis showed a mean difference of 0.09, and the area under the receiver operating characteristic curve was 0.88 (95% confidence interval 0.84 to 0.92, p <0.05). In conclusion, the DFR has a good diagnostic performance compared with FFR but 17% of the measurements were discordant. The diagnostic accuracy of the DFR was only 40% when the DFR was 0.88 to 0.90, suggesting that FFR may be useful in these arteries.