Dynamic quantitative perfusion by computed tomography (CT) and cardiac magnetic resonance (CMR) in stented patients: a sub-analysis of ADVANTAGE II study

The ADVANTAGE II study has evaluated the performance of dynamic coronary CT perfusion (CTP) in stented patient using invasive coronary angiography (ICA) and in particular invasive coronary physiology (FFR and IMR) as gold-standard. Recently, quantitative myocardial blood flow (MBF) analysis using stress cardiac magnetic resonance (CMR) has been showed to detect obstructive coronary artery disease (CAD) and coronary microvascular dysfunction (CMD). In a substudy of ADVANTAGE II we aimed to evaluate also the performance of quantitative stress CMR in comparison to CTP. The goal of the present study was to assess the diagnostic performance of CCTA, dynamic CTP, CCTA + CTP, qualitative stress CMR, quantitative stress CMR in a population of stented patients referred for non-emergent and clinically indicated ICA, FFR and IMR as the reference standard. Methods: All subjects with clinically indicated ICA underwent both vasodilator dynamic myocardial CTP and rest CTP+CCTA using a last generation scanner characterized by a 16-cm Z-axis coverage and fast (0.28 sec) gantry rotation time and underwent stress perfusion CMR using 1.5-T Discovery MR450 scanner Results: Sixty-seven patients were enrolled in the study. Four subjects were excluded as they did not undergo CTP due to the decision of the attending cardiologist (3 patients) or intolerance to CRM due to claustrophobia (1 patient). The median number of stents per patient was 2,7 (range 1-5). The mean nominal stent diameter was 3,2±1,4 mm and 47% of the stents had a nominal diameter <3.0mm. The diagnostic rate for CTA, CTP, the combined CTA+CTP assessment, qualitative and quantitative stress CMR were 69.8%, 98,4%, 100%, 93.6% and 93.6%. In the territory-based analysis, CCTA diagnostic accuracy vs QCA was 85.5%. The combined CCTA+CTP diagnostic accuracy was 96.3%, 93.8% and 85.4.% in a territory-based analysis vs QCA, FFR and IMR, respectively. Qualitative stress CMR has a significantly lower diagnostic accuracy in comparison to combined CCTA/CTP (76.4%, 77%, 80.5% vs QCA, FFR and IMR, respectively). Quantitative stress CMR using 1.94 ml/g/min as cut-off has a sensitivity of 83.3%, 77.7% and 100% vs QCA, FFR and IMR, respectively. Conclusions: The noninvasive quantitative assessment of perfusion with calculation of MBF by dynamic CTP and by quantitative stress CMR will offer an approach to evaluate the entire cascade involved in the myocardial perfusion, from epicardial coronary stenosis to microcirculation, to delineate different levels of ischemia, and to identify functionally significant stenosis as well as the presence of diffuse and balanced ischemia