Relationship of vasodilator-induced changes in myocardial oxygenation with the severity of coronary artery stenosis: a study using oxygenation-sensitive cardiovascular magnetic resonance

To explore the impact of the functional severity of coronary artery stenosis on changes in myocardial oxygenation during pharmacological vasodilation, using oxygenation-sensitive cardiovascular magnetic resonance (OS-CMR) imaging and invasive fractional flow reserve (FFR). An FFR is considered a standard of reference for assessing haemodynamic relevance of coronary artery stenosis; yet, the relationship of FFR to changes in myocardial oxygenation during vasodilator stress and thus to an objective marker for ischaemia on the tissue level is not well understood. We prospectively recruited 64 patients with suspected/known coronary artery disease undergoing invasive angiography. The FFR was performed in intermediate coronary artery stenosis. OS-CMR images were acquired using a T2*-sensitive sequence before and after adenosine-induced vasodilation, with myocardial segments matched to angiography. Very strict image quality criteria were defined to ensure the validity of results. The FFR was performed in 37 patients. Because of the strict image quality criteria, 41% of segments had to be excluded, leaving 29/64 patients for the blinded OS-CMR analysis. Coronary territories with an associated FFR of