A systematic review and meta-analysis, published ahead-of-print in the Journal of the American College of Cardiology, indicates that a negative cardiac MRI stress study is associated with a low risk of cardiovascular death and myocardial infarction; therefore, the imaging modality has good prognostic value in patients with known or suspected coronary artery disease.
Study authors Michael Lipinski and Michael Salerno from the Department of Medicine, Division of Cardiology, University of Virginia Health System, Charlottesville, USA, and others noticed that while prior meta-analyses had demonstrated that stress cardiac magnetic resonance had “excellent diagnostic accuracy for detecting significant coronary artery disease”, there were no meta-analyses summarising the prognostic utility of stress cardiac MRI. They added that several studies have investigated the prognostic value of cardiac MRI stress testing in coronary artery disease, but said these were “often limited as they are small and single-centred. Therefore, the authors performed a systematic review and meta-analysis of the published studies to better understand the prognostic benefits of the imaging modality. Lipinski et al reported: “Prognostic validation of stress cardiac MRI is critical as a negative stress cardiac MRI can be reassuring that the patient has a very low risk for major adverse cardiovascular event.”
Studies were included in the analysis and review if they used cardiac MRI stress testing to assess myocardial ischaemia and had at least six months of prognostic follow-up, but data from populations of patients with cardiomyopathy or with acute myocardial infarction within the last 14 days were excluded. Using this criteria, Lipinski et al identified 19 studies with a total of 11,636 patients with known or suspected coronary artery disease undergoing stress cardiac MRI between them. They found that, overall, 32% of patients had a positive cardiac MRI and late gadolinium enhancement (LGE) was present in 29% of patients in studies that assessed LGE.
According to the authors, patients with a positive cardiac MRI had a significantly higher annualised event rate of cardiovascular death compared with patients with a negative cardiac MRI (p<0.00002). Patients with a positive cardiac MRI also had a significantly higher annualised event rate of non-fatal myocardial infarction (p<0.0005) than those with negative findings.
Furthermore, patients whose cardiac MRI studies demonstrated LGE had a significantly increased annualised event rate of both cardiovascular death (p<0.04) and myocardial infarction (p<0.008) than patients without LGE.
Lipinski et al commented: “The findings of this systematic review and meta-analysis demonstrate that stress cardiac MRI provides excellent prognostic stratification of patients with known or suspected coronary artery disease.” They added that the data showed that patients with negative cardiac MRI had a 1% annual event rate of either cardiovascular death or myocardial infarction, which they said was a “comparable prognosis to those patients that have a negative stress myocardial perfusion imaging or stress echocardiogram”.
Concluding their findings, Lipinski et al commented: “In the current financial environment, these findings provide justification for prospective randomised trials to assess the comparative effectiveness of stress cardiac MRI in comparison to alternative stress testing modalities.”
Michael Salerno told Cardiovascular News: “This is the first meta-analysis demonstrating the very high prognostic utility of stress cardiac MRI for predicting adverse events in patients with known or suspected coronary artery disease and further provides evidence that stress cardiac MRI should be considered an excellent alternative to more established techniques such as stress nuclear myocardial perfusion imaging or stress echocardiography.”