Author + information
- Rory Hachamovitch, MD, MSc,
- Marcelo F. Di Carli, MD⁎ (, )
- SPARC Investigators
- ↵⁎Brigham and Women's Hospital, ASB L1-037C, 75 Francis Street, Boston, Massachusetts 02115
We thank Dr. McEvoy and colleagues for their comments on our paper (1). The patients included in this report of the SPARC (Study of Myocardial Perfusion and Coronary Anatomy Imaging Roles in Coronary Artery Disease [CAD]) registry did not have a prior history of CAD and were required to have intermediate to high pretest likelihood of CAD. The SPARC exclusion criteria mandated that patients be clinically stable. Thus, patients with unstable angina (resting chest pain) within 48 h of testing were excluded.
We agree with the comments that the use of patient self-reported medication changes and the relatively short-term follow-up likely overestimated the suboptimal use of medical therapy, especially given the known fact that compliance with medical therapy is reduced over time as demonstrated by Dr. McEvoy and colleagues and others. We also agree that the 1-year follow-up data from SPARC will add potentially important information on this question in symptomatic patients.
We were also surprised about the relatively low referral rate to catheterization, especially among those with high-grade CAD on computed tomography angiography. It is important to note that these relatively low referral rates to catheterization after stress cardiac single-photon emission computed tomography were first reported more than 15 years ago and confirmed by multiple studies.
Our findings indicated that an additional facet of excess testing includes the failure of referring physicians to act on the results of testing in “appropriate” patients. Although patient selection, image acquisition, image interpretation, and results communication have been identified as the key components of imaging quality (1), referring physicians' action, implicated in this process via pretest patient selection and posttest patient management, must also be considered a necessary component of the definition of imaging quality. We can no longer assume that communication of results ensures optimal patient care. Finally, we agree with Dr. McEvoy and colleagues that we were all taught that one should not order a test without a clear plan as to how the results will impact subsequent treatment. Perhaps this mantra can be revisited.
We thank Drs. Cookson and Sahebjalal for their comments and agree that before ordering a test, physicians must decide what type of information they are seeking. In the authors' example, they stated that it would be difficult for a referring physician to “ignore” a 65% left anterior descending artery stenosis on coronary computed tomography angiography and he would need to investigate further. We agree that the physiological significance of this lesion would need to be investigated, usually with a stress test. However, the use of stress myocardial perfusion imaging post–computed tomography angiography in the SPARC registry was actually relatively low.
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