Purpose: To compare the performance of myocardial perfusion imaging (MPI) versus cardiac computed tomographic angiography (CCTA) in patients with a low pretest likelihood of obstructive coronary artery disease and high-risk occupation.
Materials and methods: We performed a retrospective chart review of all MPI and CCTA studies performed at our institution from January 2006 to May 2008. The primary outcome measure was the incidence of referral to invasive coronary angiography (ICA).
Results: There were 512 MPS and 170 CCTA studies performed during the study period that met the study criteria. The average age was 35±10 for the CCTA arm and 45±5 for the myocardial perfusion scans (MPS) arm, which was statistically significant (P<0.001), with similar sex distribution between the 2 arms (21% female patients in the MPI arm and 20% female patients in the CCTA arm). The incidence of referral to ICA was 15.8% (81/512) after MPS versus 2.4% (4/170) with CCTA (P<0.001). Among patients referred for ICA, the false-positive rate was 93% (75/81) and 50% (2/4) with MPI and CCTA, respectively (P=0.043).
Conclusions: Compared with MPI, CCTA significantly reduced ICA referral and false-positive noninvasive imaging rates among symptomatic patients with a low probability of coronary artery disease but high occupational risk.