Prognostic significance of coronary artery calcium scoring and single-photon emission computed tomographic myocardial perfusion imaging on major adverse cardiac events in patients at low risk for suspected coronary artery disease

Abstract

Background: To explore the prognostic value of combination of coronary artery calcium scoring (CACS) and single-photon emission computed tomography (SPECT) on the long-term risk of major adverse cardiac events (MACEs) in Chinese patients at low risk of suspected coronary artery disease (CAD).Methods: The medical records of 1876 adult patients who were referred for clinically indicated non-invasive CAD detection with SPECT/CT from January 2011 to December 2013 were retrospectively reviewed. The primary outcome was the occurrence of MACEs, including cardiac death, non-fatal myocardial infarction (MI), unstable angina (UA), and late revascularisation.Results: During a median follow-up of 28.4 ± 9.1 months, 210 patients were identified to have at least one MACEs. Multivariate Cox regression analysis showed that patients with abnormal SPECT had more MACEs compared to those with normal SPECT (HR = 3.41, 95% CI: 2.08–4.71, p < .01). Both moderate (HR = 3.35, 95% CI: 1.76–4.32, p < .01) and severe CACS (HR = 6.56, 95% CI: 4.71–8.23, p < .01) were associated with occurrence of HACEs compared with normal CACS. Moreover, interaction terms for CACS and SPECT findings were reported to be significantly associated with MACE outcomes (p < .01).Conclusions: CACS and SPECT provided both independent and compensatory prognostic information for risk of MACE in patients at low risk of suspected CAD. Our findings strongly support adding a CACS testing in addition to SPECT in asymptomatic patients to better define the risk of cardiac events during follow-up.