Prognostic impact of myocardial perfusion single photon emission computed tomography in patients with major extracardiac findings by computed tomography for attenuation correction.

Background: Attenuation correction computed tomography (CT) contributes to an improvement in the diagnostic accuracy of myocardial perfusion imaging (MPI) by single photon emission tomography (SPECT). The aim of this study was to explore the prognosis of patients with major findings by CT according to the results of MPI.

Methods And Results: 1506 patients who underwent MPI by SPECT were retrospectively included. Attenuation correction CT images were systematically analyzed for major and minor abnormalities. 830 (55.1%) and 212 (14.1%) patients had minor and major extracardiac findings, respectively. Among patients with major extracardiac findings, the abnormality was previously unknown in 113 (53.3%) patients. 90 (41.9%) had abnormal MPI, 73 (34.4%) had a myocardial infarction scar, 55 (25.9%) had myocardial ischemia, and 38 (17.7%) patients had both myocardial infarction scar and myocardial ischemia. Among the 201 patients available for survival analysis, there were 67 (31.2%) deaths over a follow-up period of 3.2±1.3 years. There was no significant impact on survival arising from MPI, whatever the result. The results were the same among the 103 patients with previously unknown major extracardiac findings.

Conclusion: Extracardiac findings by CT during MPI are frequent. Patients with major extracardiac findings have a poor mid-term outcome, whatever the results of the myocardial perfusion imaging. Extracardiac findings should be systematically checked when attenuation correction CT is performed.