Extensive visually estimated coronary artery calcium on SPECT-MPI was independently associated with an increased risk of major adverse cardiac events (HR 3.47) compared to absent calcium.
Cohort (n=4,720)
Unblinded
No
Does visually estimated coronary artery calcium score (VECACS) from CTAC scans improve risk stratification for MACE in patients undergoing SPECT-MPI?
Visually estimated coronary artery calcium scores from routine CT attenuation correction scans during SPECT-MPI provide independent prognostic value for MACE without requiring additional radiation exposure.
Effect estimate: HR 3.47 (95% CI 2.41-5.00)
p-value: p=<0.001
AIMS: Computed tomographic attenuation correction (CTAC) scans for single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) may reveal coronary artery calcification. The independent prognostic value of a visually estimated coronary artery calcium score (VECACS) from these low-dose, non-gated scans is not established. METHODS & RESULTS: VECACS was evaluated in 4,720 patients undergoing SPECT-MPI with CTAC using a 4-point scale. Major adverse cardiac events (MACE) were defined as all-cause mortality, acute coronary syndrome, or revascularization > 90 days after SPECT-MPI. Independent associations with MACE were determined with multivariable Cox proportional hazards analyses adjusted for age, sex, past medical history, perfusion findings, and left ventricular ejection fraction. During a median follow up of 2.9 years (interquartile range 1.8 - 4.2), 494 (10.5%) patients experienced MACE. Compared to absent VECACS, patients with increased VECACS were more likely to experience MACE (all log-rank p < 0.001), and findings were similar when stratified by normal or abnormal perfusion. Multivariable analysis showed an increased MACE risk associated with VECACS categories of equivocal (adjusted hazard ratio HR 2.54, 95% CI 1.45-4.45, p = 0.001), present (adjusted HR 2.44, 95% CI 1.74-3.42, p < 0.001) and extensive (adjusted HR 3.47, 95% CI 2.41-5.00, p < 0.001) compared to absent. Addition of VECACS to the multivariable model improved risk classification (continuous net reclassification index 0.207, 95% CI 0.131 - 0.310). CONCLUSION: VECACS was an independent predictor of MACE in this large SPECT-MPI patient cohort. VECACS from CTAC can be used to improve risk stratification with SPECT-MPI without additional radiation.
Trpkov et al. (Fri,) conducted a cohort in Suspected or known coronary artery disease (n=4,720). Visually estimated coronary artery calcium score (VECACS) vs. Absent VECACS was evaluated on Major adverse cardiac events (MACE: all-cause mortality, acute coronary syndrome, or late revascularization) (HR 3.47, 95% CI 2.41-5.00, p=<0.001). Extensive visually estimated coronary artery calcium on SPECT-MPI was independently associated with an increased risk of major adverse cardiac events (HR 3.47) compared to absent calcium.