Abstract 724: The Addition of Coronary Artery Calcium Scoring (CAC) to Myocardial Perfusion Imaging (MPI) Improves Diagnostic Accuracy in the Detection of Obstructive CAD: Results of a Prospective Multicenter Trial
Background: The PICTURE Trial evaluated the accuracy of 64-CT coronary angiography (CCTA) & MPI to invasive coronary angiography (ICA) for the detection of obstructive CAD. CCTA included an evaluation of Coronary Artery Calcium. The objective of this substudy was to evaluate the combination of measures of ischemia & atherosclerosis, with MPI & CAC respectively.
Methods: 230 patients [52% male, 56.9 yrs] referred for MPI for chest pain were prospectively enrolled at 12 sites. 22% of patients underwent ICA for either abnormal MPI or coronary CCTA. The efficacy was assessed on a per-patient basis.
Results: Of the 47 patients prospectively enrolled that underwent ICA, the prevalence of a >50% stenosis by ICA was 47% (22/47). Mean CAC for all patients was 434 +/−926. The frequency of obstructive CAD based on MPI & CAC are shown in the Figure⇓. The odds (95% CI) for obstructive CAD is elevated 12.73-fold (2.43– 66.55) for ≥5% myocardium with stress defects (p<0.0001). Adding stress EF to perfusion results in a diagnostic sensitivity & specificity of 76.0% & 90.9% (p<0.0001). For CAC ≥100 alone, the diagnostic sensitivity & specificity is 76% & 72.7% (p=0.001). Adding a CAC score >100 to perfusion + EF increases the odds of obstructive CAD by 2.5-fold (1.31– 4.77, p=0.006). In patients with <5% defects, the addition of a CAC score of >100 increased the odds by 4.8-fold (0.95–24.14, p=0.057). ROC analysis revealed the % myocardium with stress defects categorized obstructive CAD with an area of 0.76 (95% CI=0.62– 0.90, p=0.002). Adding CAC improved the area to 0.85 (95% CI=0.74–0.96, p<0.0001).
Conclusion: The addition of CAC to MPI improves diagnostic accuracy in the detection of obstructive CAD.