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Improved Diagnosis through Diastolic Hyperemia-Free Ratio (DFR) over Fractional Flow Reserve (FFR) in Intermediate
Muralidharan Thoddi Ramamurthy1, Vinod Kumar Balakrishnan1, Mano Vikash Vallivedu1
1Department of Cardiology, Sri Ramachandra Medical University & Research Institute, Chennai, India.
Insights
Diastolic hyperemia-free ratio (DFR) reliably correlates with fractional flow reserve (FFR) for intermediate coronary artery stenosis. DFR offers a potential alternative to FFR, reducing the need for adenosine and associated costs.
Area of Science:
- Cardiology
- Interventional Cardiology
- Diagnostic Imaging
Background:
- Visual assessment of coronary artery stenosis is challenging, especially for intermediate lesions.
- Fractional flow reserve (FFR) is reliable but requires adenosine, causing side effects and increased costs.
- Diastolic hyperemia-free ratio (DFR) is a novel index that does not require hyperemia induction.
Purpose of the Study:
- To compare Diastolic hyperemia-free ratio (DFR) and Fractional flow reserve (FFR) measurements.
- To evaluate DFR as a diagnostic tool for intermediate coronary artery stenosis.
- To assess the potential of DFR to replace adenosine-induced FFR.
Main Methods:
- 38 intermediate coronary stenotic lesions in 25 patients were analyzed.
- Measurements included whole cycle Pd/Pa, DFR, and FFR.
- Correlation and receiver operating characteristic (ROC) analyses were performed.
Main Results:
- A significant positive correlation was found between DFR and FFR (r = 0.74; p<0.001).
- ROC analysis showed an area under the curve of 0.90 for DFR.
- A DFR-only strategy showed 74% diagnostic agreement with FFR, with 82% specificity.
Conclusions:
- Real-time DFR measurements correlate reliably with FFR.
- DFR may avoid adenosine administration, reducing cost and procedure time.
- Larger studies are needed to confirm cut-off values and endpoints.
Objectives:
To compare the fractional flow reserve (FFR) and diastolic hyperemia-free ratio (DFR) measurements in a population with intermediate coronary artery stenosis and improve the diagnosis.
Background:
Visual assessment of coronary artery stenosis severity, particularly in intermediate lesions, is prone to errors in decision-making. FFR provides a reliable assessment of functional severity in these cases but requires hyperemia induction by adenosine, which has side effects and increased cost. DFR is a novel hyperemia-independent index, which could be used as an alternative to adenosine-based hyperemia induction.
Methods And Results:
Between September 2019 to March 2020, 25 patients with 38 intermediate coronary stenotic lesions were included in the study. All patients underwent assessment of whole cycle Pd/Pa (ratio of distal coronary pressure to proximal aortic pressure), DFR and FFR. Mean whole cycle Pd/Pa, DFR and FFR were 0.93±0.06, 0.88±0.09, and 0.85±0.08, respectively. A significant positive correlation between DFR and FFR [r = 0.74; p<0.001] was observed. Receiver operating characteristic analysis showed an area under the curve of 0.90. DFR-only strategy with a treatment cut-off of ≤0.89 showed a diagnostic agreement with the FFR-only strategy in 74% of lesions, with a sensitivity of 54%, specificity of 82%, a positive predictive value of 60%, and a negative predictive value of 79%.
Conclusions:
Real-time DFR measurements show a clinically reliable correlation with FFR. Hence, using DFR is likely to avoid adenosine administration as well as reduce the cost and procedural time. Further studies with a larger sample size would be ideal to evaluate specific cut-off values and endpoints.
