Diagnostic accuracy of dynamic stress myocardial ct perfusion as compared with invasive coronary physiology assessment in patients with suspected ISR or CAD progression: results of ADVANTAGE II study
Authors: Mushtaq S , Andreini D , Conte E , Sonck J , Lorusso G , Trabattoni D , Galli S , Montorsi P , Gili S , Baggiano A , Bartorelli A , Monizzi G , Collet C , Pontone G 
Published: June 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Objectives
To compare the diagnostic performance of regadenosone-stress dynamic myocardial perfusion assessed by CT (CTP) as compared with that of coronary CT angiography (CCTA) alone by using invasive fractional flow reserve (FFR) and index of microvascular resistance (IMR) as standard of reference.

Background
Diagnostic performance of CCTA for in-stent restenosis (ISR) detection is still challenging. Recently, CTP demonstrated additional specificity and diagnostic accuracy over CCTA alone in patients with previous stent implantation and suspected IRS or progression of coronary artery disease (CAD). However, no data are available in this clinical setting on the performance of CTP by using a new technique allowing for a non-invasive adjudication of regional myocardial blood flow (Dynamic CTP) and to assess both macrovascular and microvascular disease status.

Methods
We enrolled consecutive stable patients with previous coronary stenting referred for invasive quantitative coronary angiography (QCA) for clinical indication. All patients underwent dynamic stress myocardial CTP and rest CTP+CCTA by using a last generation scanner characterized by a 16-cm Z-axis coverage and fast (0.28 sec) gantry rotation time. Invasive FFR and IMR were performed during QCA according to the standard practice. The diagnostic rate and diagnostic accuracy of CCTA and CTP were evaluated in a territory-based analyses vs. FFR, IMR (primary endpoint of the study) and QCA (secundary endpoint).

Results
In 156 enrolled patients (126 men, mean age 63.1±8.2 years), the diagnostic rate (number of territories interpretable/number of territories evaluated) of CTP was significantly higher than that of CCTA (789/799=98.7% vs. 764/799=95.6%; p = 0.0002). The mean absolute MBF values for ischemic territories (pathological FFR and/or IMR) was significantly lower as compared with those for normal territories (96 ± 32 ml/100 g/min vs. 130 ± 46 ml/100 g/min; p&lt; 0.0001). When FFR was used as gold standard, sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CTP were higher than those of CCTA (89%, 82.8%, 69.2%, 94.6% and 84.7% vs. 60%, 61.9%, 31.9%, 83.8% and 61.5%, p&lt;0.001, respectively). When IMR was used as gold standard, sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CTP were higher than those of CCTA (76.5%, 85.9%, 72.2%, 88.4% and 82.9% vs. 48.2%, 63.5%, 33.3%, 76.4% and 59.3%, p&lt;0.01, respectively). When the presence of at least one abnormal physiological parameter among FFR and IMR was used as gold standard, the diagnostic accuracy of CTP was higher than that of CCTA (90.8% vs. 68.1%, p&lt;0.001). The mean ED of the total CCTA/rest CTP/stress CTP was 5.63±4.2 mSv.

Conclusion
In patients with coronary stents, dynamic CTP significantly improves diagnostic rate and accuracy of CCTA alone in comparison with both FFR and IMR.