Author + information
- Received November 15, 2016
- Revision received February 15, 2017
- Accepted March 6, 2017
- Published online May 15, 2017.
- Sung Gyun Ahn, MD, PhDa,b,
- Jon Suh, MD, PhDb,c,
- Olivia Y. Hung, MD, PhDa,
- Hee Su Lee, BSa,
- Yasir H. Bouchi, BSa,
- Wenjie Zeng, MD, MPHa,
- Rounak Gandhi, MBBSa,
- Parham Eshtehardi, MDa,
- Bill D. Gogas, MD, PhDa and
- Habib Samady, MDa,∗ ()
- aDivision of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
- bDivision of Cardiology, Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
- cDivision of Cardiology, Department of Internal Medicine, SoonChunHyang University Bucheon Hospital, Bucheon, Korea
- ↵∗Address for correspondence:
Dr. Habib Samady, Division of Cardiology, Department of Medicine, Emory University School of Medicine, 1364 Clifton Road, F622, Atlanta, Georgia 30322.
Objectives The aim of this study was to investigate the epicardial and microvascular substrates associated with discordances between fractional flow reserve (FFR) and coronary flow reserve (CFR) values.
Background Discordances between FFR and CFR remain poorly characterized.
Methods FFR, hyperemic stenosis resistance (HSR), and intravascular ultrasound were performed as indexes of epicardial function and CFR and hyperemic microvascular resistance (HMR) as measures of microvascular function in 94 patients with moderate coronary stenosis. Maximal plaque burden (PBmax), HSR, and HMR were calculated in 4 quadrants based on values of FFR ≤0.80 and CFR ≤2.0 as follows: concordant normal (preserved FFR and CFR), concordant abnormal (low FFR and CFR), discordant low FFR and preserved CFR, and discordant preserved FFR and low CFR.
Results Sixty-four patients (68%) had concordant FFR and CFR findings, and 30 patients (32%) had discordant FFR and CFR. Compared with patients with preserved FFR and CFR, those with low FFR and CFR had higher PBmax (p = 0.003), higher HSR (p < 0.001), and similar HMR. Among patients with preserved FFR, those with reduced CFR had similar PBmax and HSR but a trend toward higher HMR (p = 0.058) compared with patients with preserved CFR. Among patients with reduced FFR, those with preserved CFR had lower PBmax (p = 0.004), a trend toward lower HSR (p = 0.065), and lower HMR (p = 0.03) compared with patients with reduced CFR. Furthermore, compared with patients with preserved FFR and low CFR, those with low FFR and preserved CFR had higher HSR (p = 0.022) but lower HMR (p = 0.003).
Conclusions In patients with moderate coronary stenosis, preserved FFR and low CFR is associated with increased microvascular resistance, while low FFR and preserved CFR has modest epicardial stenosis and preserved microvascular function.
- blood flow velocity
- coronary atherosclerosis
- intravascular ultrasonography
- microvascular angina
- myocardial fractional flow reserve
Drs. Ahn and Suh have been supported by the CardioVascular Research Foundation, Korea. Drs. Hung and Eshtehardi have been supported by a National Research Service Award training grant (5T32HL007745). Dr. Samady has received research funding from Volcano Corporation, St. Jude Medical, Medtronic, and Abbott Vascular. All other authors have reported that they have no relationships relevant to the content of this paper to disclose. Drs. Ahn and Suh contributed equally to the work.
- Received November 15, 2016.
- Revision received February 15, 2017.
- Accepted March 6, 2017.