Long-Term Prognostic Value of 13N-Ammonia Myocardial Perfusion Positron Emission Tomography: Added Value of Coronary Flow Reserve
Received 7 October 2008; received in revised form 30 January 2009; accepted 17 February 2009.
Refers to article:
Quantification of Myocardial Flow Reserve Using Positron Emission Imaging: The Journey to Clinical Use⁎Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology.
Rob S.B. Beanlands, Maria Cecilia Ziadi, Kathryn Williams
Journal of the American College of Cardiology
7 July 2009 (Vol. 54, Issue 2, Pages 157-159) Full Text |
Full-Text PDF (144 KB)
Objectives
The goal of this study was to assess the predictive value of myocardial perfusion imaging with 13N-ammonia positron emission tomography (PET) and coronary flow reserve (CFR) on long-term prognosis in patients with suspected myocardial ischemia.
Background
No prognostic data exist on the predictive value of CFR and 13N-ammonia PET.
Methods
Perfusion and CFR were assessed in 256 patients using 13N-ammonia PET, and follow-up was obtained in 245 (96%) patients. Sixteen early revascularized patients were excluded and 229 were assigned to normal versus abnormal perfusion or normal versus abnormal CFR (<2.0). Major adverse cardiac events (MACE) (cardiac death, nonfatal myocardial infarction, late revascularization, or hospitalization for cardiac reasons) were assessed using the Kaplan-Meier method. Cox proportional hazard regression was used to identify independent predictors for cardiac events.
Results
During follow-up (5.4 ± 2.2 years), 78 patients had at least 1 cardiac event, including 29 cardiac deaths. Abnormal perfusion (n = 126) was associated with a higher incidence of MACE (p < 0.001) and cardiac death (p < 0.05). In patients with normal perfusion, abnormal CFR was independently associated with a higher annual event rate over 3 years compared with normal CFR for MACE (1.4% vs. 6.3%; p < 0.05) and cardiac death (0.5% vs. 3.1%; p < 0.05). In abnormal perfusion, CFR remained predictive throughout the 10-year follow-up (p < 0.001).
Conclusions
Perfusion findings in 13N-ammonia PET and CFR are strong outcome predictors. CFR allows further risk stratification, suggesting a “warranty” period of 3 years if normal CFR is associated with normal perfusion. Conversely, in patients with abnormal perfusion, an impaired CFR has added value for predicting adverse outcomes.
⁎Cardiac Imaging Section, University Hospital Zurich, Zurich, Switzerland
†Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
Reprint requests and correspondence: Dr. Philipp A. Kaufmann, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
Dr. Kaufmann was supported by a grant from the Swiss National Science Foundation (SNSF-professorship grant no. PP00A-114706) and by the ZIHP (Zurich Center for Integrative Human Physiology, University of Zurich, Switzerland).
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