Assessing the downstream value of first-line cardiac positron emission tomography (PET) imaging using real world Medicare fee-for-service claims data

Background Higher imaging quality makes cardiac positron emission tomography (PET) desirable for evaluation of suspected coronary artery disease (CAD). High cost of PET imaging may be offset by reduced utilization and/or improved outcomes. Methods This retrospective observational study utilized Medicare fee-for-service dataset. Study participants had no CAD diagnosis within 1 year prior to initial imaging. The PET group (PET imaging) and propensity score matched comparison group (single photon emission computed tomography or stress echocardiography) underwent index imaging between January 2014 and December 2016. Outcomes were analyzed using generalized linear models. Results Among 144,503 study subjects, 4619 (3.2%) had PET and 139,884 (96.8%) had conventional imaging. After matching, each group had 4619 patients (mean age 74 years, 59% female). The PET group had lower radiation exposure (3.8 milliSievert less per year, 95% CI - 3.96 to - 3.64,P < .0001) and unstable coronary syndrome (incidence rate ratio (IRR) 0.77, 95% CI 0.64-0.94,P = .008). The PET group experienced more hospital admissions (IRR 1.10, 95% CI 1.06-1.15,P < .0001), more use of percutaneous coronary intervention (IRR 1.24, 95% CI 1.02-1.50,P = 0.03), while similar mortality rate (hazard ratio 0.95, 95% CI 0.78-1.14,P = 0.55). The PET group had higher medical spending ($2358.2 vs $1774.3, difference = $583.9 per patient per month,P < .0001). Conclusions First-line PET imaging was not associated with reduced levels of utilization and spending. Clinical outcomes were mostly similar.