Stress myocardial perfusion with qualitative magnetic resonance and quantitative dynamic computed tomography: comparison of diagnostic performance and incremental value over coronary computed tomography angiography

Aims: Assessment of haemodynamically significant coronary artery disease (CAD) using cardiovascular magnetic resonance (CMR) imaging perfusion or dynamic stress myocardial perfusion imaging by computed tomography (CT perfusion) may aid patient selection for invasive coronary angiography (ICA). We evaluated the diagnostic performance and incremental value of qualitative CMR perfusion and quantitative CT perfusion complementary to cardiac computed tomography angiography (CCTA) for the diagnosis of haemodynamically significant CAD using fractional flow reserve (FFR) and quantitative coronary angiography (QCA) as reference standard.

Methods and results: CCTA, qualitative visual CMR perfusion, visual CT perfusion, and quantitative relative myocardial blood flow (CT-MBF) were performed in patients with stable angina pectoris. FFR was measured in coronary vessels with stenosis visually estimated between 30% and 90% diameter reduction on ICA. Haemodynamically significant CAD was defined as FFR <0.80, or QCA ≥80% in those cases where FFR could not be performed. A total of 218 vessels from 93 patients were assessed. An optimal cut-off of 0.72 for relative CT-MBF was determined. The diagnostic performances (area under the receiver-operating characteristics curves, 95% CI) of visual CMR perfusion (0.84, 0.77-0.90) and relative CT-MBF (0.86, 0.81-0.92) were comparable and outperformed visual CT perfusion (0.64, 0.57-0.71). In combination with CCTA ≥50%, CCTA + visual CMR perfusion (0.91, 0.86-0.96), CCTA + relative CT-MBF (0.92, 0.88-0.96), and CCTA + visual CT perfusion (0.82, 0.75-0.90) improved discrimination compared with CCTA alone (all P < 0.05).

Conclusion: Visual CMR perfusion and relative CT-MBF outperformed visual CT perfusion and provided incremental discrimination compared with CCTA alone for the diagnosis of haemodynamically significant CAD.