Invasive testing leads to significantly altered (surgical) management strategy in coronary anomalies with interarterial course: 3 year interim analysis of MuSCAT
Authors: Verheijen D B H , Van Der Kley F , Egorova A D , Jongbloed M R M , Koolbergen D R , Hazekamp M G , Beijk M A M , De Winter R J , Damman P , Wagenaar L J , Post M , Voskuil M , Jukema J W , Kies P , Vliegen H W 
Published: October 2024

Abstract

Introduction
Diagnostic work-up of patients with an anomalous aortic origin of a coronary artery (AAOCA) includes an anatomical and functional assessment. The approach to functional evaluation currently varies widely and mainly includes noninvasive assessment. Intracoronary hemodynamic assessment can potentially enhance risk assessment for myocardial ischemia and sudden cardiac death and guide management of AAOCA patients. Hence, this study aims to evaluate invasive detection of ischemia on top of the standard of care diagnostic work-up for interarterial or intraseptal AAOCA and the impact on patient management. We report the first clinical outcomes.

Methods
In this multicenter prospective cohort study on AAOCA, all consecutive patients of 16 years and older with AAOCA with a newly diagnosed interarterial or intraseptal course in whom diagnostic work-up according to the protocol of the MuSCAT trial was performed between January 2021 and January 2024, were included for analysis. Exclusion comprised incomplete diagnostic evaluation, hemodynamically significant concomitant congenital heart disease or obstructive coronary artery disease in the AAOCA effluence. The work-up included invasive ischemia testing using fractional flow reserve (FFR) and or instantaneous wave-free ratio (iFR)/resting full-cycle ratio (RFR) at baseline and during pharmacological stress using adenosine, adrenaline and dobutamine.

Results
Fifty-eight patients (50% female, median age at AAOCA diagnosis 51.5 years (IQR 44.0-59.0)) were included, Table 1. The right coronary artery was anomalous in 88%, 93% patients had an interarterial and 69% an intramural course. Non-invasive ischemia detection was positive in 12%, negative in 84% and inconclusive in 4%. Invasive hemodynamic assessment was positive for ischemia in 22%, negative in 74% and inconclusive in 3%. Class of recommendation for surgery based on ESC guidelines was I or IIa in 28% patients and IIb, III or unclassified in 72%. Invasive hemodynamic assessment changed the treatment decision in 24% of the patients; 50% with initially recommended surgical treatment and 14% with initially a conservative treatment adjudication, Figure 1.
Median follow-up after initial diagnosis was 20 [IQR 10-28] months and in 56% of all patients who completed 6 months follow-up the initial symptoms alleviated. One (2%) patient underwent a percutaneous re-intervention of the operated AAOCA.

Conclusions
This national prospective study of invasive hemodynamic assessment in patients with AAOCA showed clinically significant impact on the adjustment of initial management strategy in 24% of the patients. No cardiac death of myocardial infarction in the AAOCA supply area occurred during follow-up. Analysis of the complete follow-up of the MuSCAT trial can further substantiate the role of additional invasive functional imaging in AAOCA.