Anatomic or Functional Evaluation as an Initial Test for Stable Coronary Artery Disease: A Propensity Score Analysis

Little data are available to compare the clinical implications of coronary angiography (CAG) or myocardial perfusion imaging (MPI) as an initial evaluation for stable coronary artery disease (CAD). From national health insurance claims data in South Korea, patients aged 18 y or older without a known history of CAD, who underwent CAG or MPI for the diagnosis of stable CAD between 2009 and 2013, were enrolled. Patients were divided into CAG (n = 117,134) and MPI (n = 19,932) groups. The primary endpoint, defined as a composite of all-cause death and myocardial infarction, was compared by a propensity score analysis between the 2 groups. There was a significant increase (39%) in the annual rate of CAG from 23,985 in 2009-2010 to 33,373 in 2012-2013. However, a substantial reduction (41%) in the annual MPI rate was also noted from 6,389 in 2009-2010 to 3,790 in 2012-2013. During the follow-up period (median, 2.4 y; interquartile range, 1.5-3.5), coronary revascularization was more frequently performed in the CAG group (adjusted hazard ratio [aHR] of CAG, 24.15; 95% confidence interval [CI], 19.66-29.68; P < 0.001). However, the incidence of the primary endpoint was significantly higher in the CAG group (aHR, 1.26; 95% CI, 1.17-1.36; P < 0.001). The individual endpoints of death (aHR, 1.16; 95% CI, 1.06-1.25; P = 0.001) and myocardial infarction (aHR, 1.95; 95% CI, 1.60-2.36; P < 0.001) were also higher in the CAG group. As an initial diagnostic test in patients with stable CAD, MPI is associated with a better clinical outcomes than CAG.