Assessment of coronary artery bypass graft disease using cardiovascular magnetic resonance determination of flow reserve

The purpose of this study was to assess the value of cardiovascular magnetic resonance (CMR)–determined graft flow and flow reserve in differentiating significant from non-significant vein graft disease. In patients after coronary artery bypass grafting (CABG), non-invasive testing may be helpful in the detection of recurrent graft disease. Randomly selected patients (n = 21) scheduled for X-ray angiography because of recurrent chest complaints after CABG were included for evaluation of vein grafts (n = 40) by CMR. Three-dimensional contrast-enhanced CMR angiography was performed and followed by flow measurements at rest and during hyperemia in patent grafts only. Flow reserve was calculated when resting flow exceeded 20 ml/min. Analysis was based on four categories defined by X-ray angiography: occluded grafts (n = 3), grafts with stenosis >50% (n = 19), grafts with stenosis