AUTHOR=Milzi Andrea , Dettori Rosalia , Lubberich Richard Karl , Burgmaier Kathrin , Marx Nikolaus , Reith Sebastian , Burgmaier Mathias 

TITLE=Coronary microvascular dysfunction as assessed by angiography-derived index of microvascular resistance co-localizes with and may explain the presence of ischemia in stress-cardiac magnetic resonance imaging in the absence of coronary artery disease

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2022.1060764

DOI=10.3389/fcvm.2022.1060764

ISSN=2297-055X

ABSTRACT=Introduction: Ischemia with no obstructive coronary disease (INOCA) is a frequent phenomenon in the cath lab. A possible cause is coronary microvascular dysfunction, which may be assessed by invasive testing with possible complication; therefore, less invasive approaches have emerged, such as the angiography-derived index of microvascular resistance (aIMR). The aim of our study was assessing the association of single-vessel aIMR as a measure of coronary microvascular dysfunction with areas of INOCA in stress testing.

Methods: We measured aIMR in 286 vessels from 102 patients undergoing both stress cMRI and coronary angiography. Groups were a) INOCA group (93 vessels, 32 patients); b) coronary artery disease (CAD) control group (116 vessels, 42 patients) with ischemia due to relevant stenosis; and c) control group (77 vessels, 28 patients) without ischemia or relevant stenosis.

Results: INOCA patients presented higher mean aIMR (28.3±5.7) compared to both CAD patients (17.4±5.7, p<0.001) and controls (22.1±5.9, p<0.001). Furthermore, in INOCA patients aIMR was significantly increased (33.0±8.1 vs 25.8±6.3, p=0.021) in vessels with vs without ischemia. Single vessel aIMR presented a very good diagnostic efficiency in detecting INOCA (AUC 0.865(0.804-0.925), optimal cut-off 27.1, p<0.001).

Conclusion: Coronary microvascular dysfunction, as assessed by 3-vessel aIMR, co-localizes with and explains the presence of ischemia in stress-cMRI in INOCA.