Temporal changes in PET myocardial perfusion imaging over 15 years: patient characteristics and imaging findings

Abstract

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): DF. Sager was supported by the Swiss Academy of Medical Sciences and the G.&J. Bangerter-Rhyner Foundation through the “Young Talents in Clinical Research” program. Background & Purpose Positron emission tomography (PET)/computed tomography (CT) myocardial perfusion imaging (MPI) is guiding the assessment and management of patients with suspected or known coronary artery disease for over 30 years. Its clinical dissemination and technological evolution might have altered the clinical phenotype of referred patients. The aim of the present study was to investigate temporal trends in patient characteristics, imaging findings of PET/CT MPI and outcome over the course of 15 years. Methods In this cross-sectional cohort study, 1366 patients who underwent PET/CT between 2001 and 2015 were retrospectively included. Patients were grouped together into three 5-year study groups (group 1: 2001–2005 / group 2: 2006–2010 / group 3: 2011–2015) and assessed for patient demographics and characteristics, serological biomarkers, relative and quantitative PET findings, and mortality. Vital status was obtained from medical charts and/or death notices. Results Across study groups, mean age (p<0.001) and creatinine (p = 0.006) increased while the prevalence of typical angina (p<0.001) and known coronary artery disease (p = 0.003) decreased (Table). There were no temporal changes in neither the prevalence of dyspnea (p = 0.480) and diabetes mellitus (p = 0.146) nor median body mass index (p = 0.064), NT-proBNP (p = 0.532) and troponin (p = 0.385). Although the prevalence of ischemia (p = 0.019) and scar (p = 0.003) decreased over time, median myocardial flow reserve (MFR) worsened (p = 0.001). Over a median follow-up of 5.3 years [interquartile range 3.3–7.4] annualized mortality increased across groups in parallel to the changes in MFR (Figure). Conclusion The clinical phenotype of patients referred for PET/CT MPI has changed marginally between 2001 and 2015. The temporal trend towards older, less symptomatic patients with lower prevalence of ischemia and scar but worse MFR and higher mortality highlights the importance of assessing diffuse atherosclerosis and microcirculation beyond focal stenosis to improve risk stratification.