Evaluation of the American College of Cardiology Foundation/American Society of Nuclear Cardiology appropriateness criteria for SPECT myocardial perfusion imaging in an Asian tertiary cardiac center.

BACKGROUND: Appropriate use criteria (AUC) for SPECT MPI have been published to address concern about the growth of cardiac imaging studies and the effective use of imaging, but there is no published data on its role outside the United States.
METHODS: All consecutive patients referred to the MPI laboratory of our center from February 16 to June 19, 2009 were prospectively studied. Patients' medical records and stress data were collected and all imaging results were recorded. Based on AUC, MPI studies were classified into appropriate, inappropriate, uncertain, or unclassified. MPI studies were classified on the basis of their results into normal or abnormal scans.
RESULTS: There were 1,623 patients (mean age 61 years ± 11, 61% males). Most common indications for SPECT were evaluation of ischemic equivalent for coronary artery disease (CAD), risk assessment post-revascularization, and preoperative evaluation for non-cardiac surgery. 10% of referrals were classified as inappropriate, 5% uncertain, and 3% unclassified. Women (48.4% vs 40.6% for men, P = .063) and asymptomatic patients (50.2% vs 14.3% for symptomatic, P < .001) had a higher proportion of inappropriate studies. The preoperative group had the highest proportion of inappropriate studies (59%). Appropriate referrals had a higher proportion of abnormal SPECT results than inappropriate referrals (40% vs 27%, OR 2.08, 95% CI 1.56-2.77, P < .001).
CONCLUSIONS: The pattern of referrals for SPECT MPI in an Asian center appears to vary from published reports in the United States. Preoperative evaluation for low-risk surgery appears to be the most common source of inappropriate referrals in our institution. Inappropriate referrals have a higher proportion of normal studies, but 27% were still reported as abnormal.