Author + information
- Nils P. Johnson, MD, MS,
- Richard L. Kirkeeide, PhD and
- K. Lance Gould, MD∗ ()
- ↵∗Weatherhead PET Center for Preventing and Reversing Atherosclerosis, University of Texas Medical School at Houston, 6431 Fannin Street, Room 4.256 MSB, Houston, Texas 77030
Dr. Sen and colleagues fail to see their own contradiction by colorfully calling for “overturning the decades-long dogma of…hyperemia” yet simultaneously proposing the hyperemic stenosis resistance (HSR) as a reference standard (1). Only cognitive dissonance could allow “dogma” to serve as a reasonable arbiter.
Although HSR has been proposed as a physiological index of stenosis severity, currently its limited supporting data come from a handful of publications at a single institution over the past 10 years. By contrast, fractional flow reserve (FFR) has a robust, extensive, multicenter evidence base including now 3 randomized, controlled trials of clinical outcomes.
The statement by Dr. Sen and colleagues is simply incorrect that “RESOLVE…arrived at very different conclusions” from those in our paper. Using the proprietary Volcano algorithm for instantaneous wave-free ratio (iFR), the RESOLVE registry (2) reproduced exactly the extremely linear relationship (r2 = 0.95; p < 0.001) between rest Pd/Pa and iFR, as in our paper's Figure 5, and the “intertwining” of adenosine versus FFR agreement curves, as in our paper's Figure 3B. Rest Pd/Pa offers the same diagnostic performance as iFR compared with FFR.
Furthermore, the reproducibility claim by Dr. Sen and colleagues regarding “lower-than-expected agreement in FFR” contradicts the published literature. VERIFY (VERification of Instantaneous Wave-Free Ratio and Fractional Flow Reserve for the Assessment of Coronary Artery Stenosis Severity in EverydaY Practice) demonstrated 95% limits of agreement for repeated FFR measurements of ±0.04, narrower than the wider ±0.07 variability in iFR (3).
We emphasize that their table does not appear in any of our publications, abstracts, or conference presentations. At best, the table constitutes misattribution. Worryingly, such misattribution in their letter parallels that at their public, not peer-reviewed, website (4) and conference presentations. Specifically, the quoted words “are most accurately assessed” attributed to Gould do not appear in this decades-old and apparently dogmatic paper (5), either exactly or in spirit. We demand that Sen and colleagues constrain their speculation to the literature as published.
Resting electrocardiography, echocardiography, and perfusion imaging play key roles in daily cardiology practice. However, the stress versions of these tests often prove more useful for triage to invasive cardiac catheterization. Do Sen and colleagues only offer “rest tests” to their patients instead of stress tests?
To answer the question posed in the title of their letter, we agree that lower is not better–for diagnostic accuracy or patient survival.
Please note: All authors received internal funding from the Weatherhead PET Center for Preventing and Reversing Atherosclerosis. All authors have nonfinancial, mutual nondisclosure agreements to discuss coronary physiology with Volcano Corporation, maker of invasive FFR and CFR wires.
- American College of Cardiology Foundation
- Johnson N.P.,
- Kirkeeide R.L.,
- Asrress K.N.,
- et al.
- ↵Jeremias A. iFR vs. Resting Pd/Pa vs. FFR — Lessons from the RESOLVE Registry. Paper presented at: 14th Canadian Coronary Physiology and Invasive Imaging Workshop (CPI 2013); Montréal, Quebec, Canada; January 30, 2013.
- Berry C.,
- van 't Veer M.,
- Witt N.,
- et al.
- ↵Davies JE, Petraco R, Sen S. Slide 9 of lecture 3, “Benefits of the diastolic wave-free period” at Advanced Coronary Physiology. Available at: http://www.simplephysiology.info/. Accessed March 21, 2013.
- Gould K.L.