Coronary CT angiography diagnostics compared head-to-head

The Danish DanNICAD-2 study compared the diagnostic accuracy of stress myocardial perfusion imaging (MPI) via 3T cardiac magnetic resonance (CMR) with rubidium positron emission tomography (^RbPET) in patients with putative obstructive stenosis undergoing routine coronary CT angiography, compared with invasive coronary angiography-fractional flow reserve (ICA-FFR). The study showed that CMR stress and ^RbPET stress had similarly moderate sensitivities coupled with high specificities in predicting FFR results.

Prof. Morten Bøttcher (Aarhus University, Denmark) presented the findings from DanNICAD-2 (NCT03481712) [1]. Consecutive patients (n=1,732, median age 59 years; 57% men) with symptoms indicating putative obstructive coronary artery disease (CAD) underwent routine coronary CT angiography. The results from the CT angiography identified 445 patients (26%) had >50% diameter stenosis, who were then referred to CMR and ^RbPET. Of those, 372 patients completed both CMR and ^RbPET and were included in the current analysis.

In that cohort with both imaging diagnostics, ICA-FFR identified obstructive CAD in 44.1%. The sensitivities of the diagnostics were similar: 59% for CMR and 64% for ^RbPET (P=0.21). Specificities numerically favoured ^RbPET at 89% versus 84% for CMR (P=0.08). The overall accuracy favoured ^RbPET over CMR as well (78% vs 73%, respectively; P=0.03). Both techniques identified lesions with >70% diameter stenosis with a sensitivity of 83% for CMR, and 89% for ^RbPET.

Prof. Bøttcher commented that “A perfusion test approach appears to be safe as almost all patients with serious disease were diagnosed. But the modest sensitivities to predict low FFR means that there was often a discrepancy between these advanced perfusion results and the invasive FFR. The accuracy of coronary CT angiography needs to improve so that more patients without obstructive CAD avoid further investigations. This might be achieved through better CT image quality and perhaps by more advanced image analyses like non-invasive FFR estimation and photon counting systems.”

1. Bøttcher M, et al. DanNICAD-2 – Perfusion scanning with MR or PET after a positive CT coronary angiography. Hot Line Session 7, ESC Congress 2022, Barcelona, Spain, 26–29 August.

 

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Posted on 27 October, 202226 October, 2022