Author + information
- Riccardo Liga, MD and
- Danilo Neglia, MD, PhD⁎ ()
- ↵⁎Fondazione Toscana G. Monasterio and CNR, Institute of Clinical Physiology, Via G. Moruzzi 1, 56124 Pisa, Italy
We read with great interest the study by Naya et al. (1) on the relationship between coronary atherosclerosis, detected by computed tomography angiography (CTA), and myocardial blood flow and flow reserve (MFR), measured by positron emission tomography (PET).
Naya et al. (1) studied the association between plaque morphology, composition, and severity, on the one hand, and myocardial perfusion, on the other, in a population with known or suspected coronary artery disease (CAD). They observed that the “summed stenosis score,” an indicator of vessel atherosclerotic burden, was a better predictor of depressed regional MFR than stenosis severity. Moreover, the modified Duke CAD index, an indicator of the presence and extent of significant coronary lesions, was the major determinant of global MFR. The authors concluded that MFR is influenced especially by the presence and severity of coronary luminal narrowings, underplaying the influence of CTA descriptors of coronary atherosclerotic burden.
Coincidentally, we recently reported a study that analyzed the relationships between coronary stenoses and vessel structure assessed by CTA, PET-derived MFR, and cardiovascular risk factors (2). We showed that abnormal wall structure affects regional MFR beyond the presence and severity of coronary stenoses. Specifically, coronary calcium content was the main determinant of regional MFR and a significant predictor of depressed global MFR. Interestingly, when the Framingham risk score, an indicator of overall cardiovascular risk, was considered; it remained the only significant determinant of global MFR, beyond CTA variables.
Although the 2 investigations are similar with regard to baseline characteristics of patients and differ only slightly in their methodology, they come to apparently different conclusions. In our view, however, both studies point to the effects of diffuse coronary atherosclerosis, in addition to those of focal significant stenoses, on myocardial perfusion.
Accordingly, depressed regional MFR is closely linked to the coronary atherosclerotic burden in the related vessel, described by the summed stenosis score in the study by Naya et al. (1) and by the coronary calcium content in ours (2). Moreover, global MFR is consistently related to different indicators of cardiovascular risk, the Duke CAD index in the study by Naya et al. (1), and the Framingham risk score in ours (2).
- American College of Cardiology Foundation
- Naya M.,
- Murthy V.L.,
- Blankstein R.,
- et al.
- Liga R.,
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