Evaluating the Prognostic Value of Positron‐Emission Tomography Myocardial Perfusion Imaging Using Automated Software to Calculate Perfusion Defect Size

Abstract

Background: Myocardial perfusion imaging by positron-emission tomography (PET MPI) is regarded as a valid technique for the diagnosis of coronary artery disease (CAD), but the incremental prognostic value of PET MPI among individuals with known or suspected CAD is not firmly established. Hypothesis: Myocardial perfusion defect sizes as measured by PET MPI using automated software will provide incremental prognostic value for cardiac and all-cause mortality. Methods: This study included 3739 individuals who underwent rest-stress rubidium-82 PET MPI for the evaluation of known or suspected CAD. Rest, stress, and stress-induced myocardial perfusion defect sizes were determined objectively by automated computer software. Study participants were followed for a mean of 5.2 years for cardiac and all-cause mortality. Cox proportional hazards models were developed to evaluate the incremental prognostic value of PET MPI. Results: A strong correlation was observed between perfusion defect sizes assessed visually and by automated software (r = 0.76). After adjusting for cardiac risk factors, known CAD, noncoronary vascular disease, and use of cardioprotective medications, stress perfusion defect size was strongly associated with cardiac death (P < 0.001). Rest perfusion defects demonstrated a stronger association with cardiac death (P < 0.001) than stress-induced perfusion defects (P = 0.01), yet both were highly significant. Similar patterns held for all-cause death. Conclusions: The current study is the largest to date demonstrating PET MPI provides incremental prognostic value among individuals with known or suspected CAD. Automated calculation of perfusion defect sizes may provide valuable supplementary information to visual assessment.

Prognostic Value of Stress Myocardial Perfusion Positron Emission Tomography

“…Data from some of the patients (n=3,884) were included in prior publications. (2,4,6,8,9) Each center had institutional review board approval for the study. Study methods are shown in much greater detail in the Appendix section.…”

External validation of models for estimating pretest probability of coronary artery disease among individuals undergoing myocardial perfusion imaging

“…The current study is comprised of 2383 patients who underwent clinically-indicated, rest-stress Rubidium-82 (Rb82) PET MPI for the evaluation of stable symptoms suggestive of obstructive CAD [20]. Patients with a known history of myocardial infarction, percutaneous coronary intervention, or coronary bypass surgery were excluded from the current study, as were those undergoing PET MPI for the evaluation of a possible acute coronary syndrome.…”

“…The software allows estimating the size of relative perfusion defects at multiple severity thresholds. In the current study, the PET parameter of interest is perfusion defect size defined as the percent of the LV myocardium with relative tracer uptake (perfusion) less than 60% of maximum [20,24]. Perfusion defect size was calculated at rest and during stress.…”

“…At the time of PET MPI, information pertaining to demographics, physical examination, cardiac risk factors, medical history, medications, and indication(s) for PET MPI were gathered and stored in patients' medical records. According to a pre-specified research protocol, the aforementioned data elements were retrospectively gathered by trained personnel from paper medical records and transcribed into a research database as previously described [20]. The parent study was approved by the Institutional Review Board at the University at Buffalo who granted a waiver of patient consent [20].…”

“…According to a pre-specified research protocol, the aforementioned data elements were retrospectively gathered by trained personnel from paper medical records and transcribed into a research database as previously described [20]. The parent study was approved by the Institutional Review Board at the University at Buffalo who granted a waiver of patient consent [20].…”