Background: 

Stress cardiac magnetic resonance tomography (stress CMR) is considered the reference standard among non-invasive imaging modalities to identify functional significant coronary artery disease (CAD). Previous studies evaluated outcome of patients with suspected coronary artery disease and negative stress CMR and have demonstrated an excellent prognosis for patients without inducible ischemia. However, the prognosis of patients with severe coronary artery stenosis without inducible ischemia using stress CMR remains uncertain.

Purpose: 

We analysed the outcome of patients with known CAD with moderate (50 – 75 %) to severe (> 75 %) stenosis assessed by invasive coronary angiography (ICA) and no evidence of inducible ischemia on adenosine or dobutamine stress CMR.

Methods: 

One hundred sixty-nine patients who underwent either adenosine or dobutamine stress CMR between February 2015 and December 2016 without evidence of inducible ischemia and known CAD on ICA performed six months before or after stress CMR were included in this retrospective analysis. ICA was performed before stress CMR for suspected coronary artery disease or for myocardial infarction. Follow-up consisted of a clinical visit as part of usual care or by direct contact with the patient. Primary endpoint was defined as the occurrence of a major cardiovascular event (MACE), including cardiac death, non-fatal myocardial infarction, percutaneous coronary intervention or coronary artery bypass graft surgery. 

Results: 

87 patients with moderate and 82 with severe coronary artery stenoses were identified. The primary endpoint occurred in 39 patients during a median follow-up of 5.6 years: 17 events (19.5 %) occurred in patients with moderate coronary artery stenoses and 22 events (26.8 %) in patients with severe stenoses (p = 0.26), primarily driven by PCI (14 events in each groups, 16.1 % and 17.1 %, respectively; p = 0.86). There was no significant difference in outcome between patients with moderate and severe stenoses (p = 0.70). In a subgroup analysis there was no significant difference in outcome between patients with severe proximal or severe distal stenoses.

Discussion: 

Patients with severe and moderate coronary artery stenoses had a similar outcome in terms of MACE when stress CMR revealed no inducible myocardial ischemia. These preliminary data highlight that stress CMR might be suitable for risk stratification before invasive revascularization in high-risk patients.