Author + information
- Received July 3, 2018
- Revision received July 27, 2018
- Accepted August 1, 2018
- Published online November 5, 2018.
- Raksha Indorkar, MDa,
- Raymond Y. Kwong, MDb,
- Simone Romano, MDc,
- Brent E. White, MDa,
- Richard C. Chia, MDa,
- Michael Trybula, MDa,
- Kaleigh Evans, MDa,
- Chetan Shenoy, MDd and
- Afshin Farzaneh-Far, MD, PhDa,e,∗ (, )@afshinfarzan
- aDivision of Cardiology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
- bDivision of Cardiology, Department of Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts
- cDepartment of Medicine, University of Verona, Verona, Italy
- dDivision of Cardiology, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
- eDivision of Cardiology, Department of Medicine, Duke University, Durham, North Carolina
- ↵∗Address for correspondence:
Dr. Afshin Farzaneh-Far, Division of Cardiology, University of Illinois at Chicago, 840 South Wood Street, M/C 715, Suite 920 S, Chicago, Illinois 60612.
Objectives The aim of this study was to evaluate the incremental prognostic value of global coronary flow reserve (CFR) in patients with known or suspected coronary artery disease who were undergoing stress cardiac magnetic resonance (CMR) imaging.
Background Coronary microvascular dysfunction results in impaired global CFR and is implicated in the development of both atherosclerosis and heart failure. Although noninvasive assessment of CFR with positron emission tomography provides independent prognostic information, the incremental prognostic value of CMR-derived CFR remains unclear.
Methods Consecutive patients undergoing stress perfusion CMR were prospectively enrolled (n = 507). Coronary sinus flow was measured using phase-contrast imaging at baseline (pre) and immediately after stress (peak) perfusion. CFR was calculated as the ratio of peak to pre-flow. Patients were followed for major adverse cardiac events (MACE): death, nonfatal myocardial infarction, heart failure hospitalization, sustained ventricular tachycardia, and late revascularization. Cox proportional hazards regression modeling was used to examine the association between CFR and MACE. The incremental prognostic value of CFR was assessed in nested models.
Results Over a median follow-up of 2.1 years, 80 patients experienced MACE. By Kaplan-Meier analysis, the risk of MACE was significantly higher in patients with CFR lower than the median (2.2) (log-rank p < 0.001); this remained significant after adjustment for the presence of ischemia and late gadolinium enhancement (LGE) (log-rank p < 0.001). CFR was significantly associated with the risk of MACE after adjustment for clinical and imaging risk factors, including ischemia extent, ejection fraction, and LGE size (hazard ratio: 1.238; p = 0.018). Addition of CFR in this model resulted in significant improvement in the C-index (from 0.70 to 0.75; p = 0.0087) and a continuous net reclassification improvement of 0.198 (95% confidence interval: 0.120 to 0.288).
Conclusions CMR-derived CFR is an independent predictor of MACE in patients with known or suspected coronary artery disease, incremental to common clinical and CMR risk factors. These findings suggest a role for CMR-derived CFR in identifying patients at risk of adverse events following stress CMR, even in the absence of ischemia and LGE.
- cardiac magnetic resonance imaging
- coronary artery disease
- coronary flow reserve
- coronary microvascular function
- stress testing
Dr. Shenoy was supported by National Institutes of Health grant K23HL132011. Dr. Farzaneh-Far has received partial funding support from Astellas Pharma, but the company had no input on study design, endpoint adjudication, cardiac magnetic resonance interpretation, data analysis, or manuscript writing. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Dudley Pennell, MD, served as Guest Editor for this paper.
- Received July 3, 2018.
- Revision received July 27, 2018.
- Accepted August 1, 2018.
- 2018 American College of Cardiology Foundation
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