Evaluation of myocardial viability with cardiac magnetic resonance imaging

Area of Science:

• Cardiology
• Medical Imaging
• Clinical Diagnosis

Background:

• Myocardial viability assessment is crucial for diagnosing stunning or hibernation.
• It aids in pre-revascularization decisions, particularly for high-risk patients.
• Observational data suggest improved outcomes post-revascularization in patients with dysfunction and viability.

Purpose of the Study:

• To review the clinical and scientific significance of myocardial viability assessment.
• To discuss current mainstays of viability testing: dobutamine stress echocardiography, nuclear imaging, and cardiovascular magnetic resonance.
• To highlight the need for further research, especially multicenter trials, on viability testing's role in ischemic cardiomyopathy.

Main Methods:

• Review of observational and randomized evidence regarding myocardial viability testing.
• Discussion of imaging modalities: dobutamine stress echocardiography (contractile function), nuclear imaging (cellular metabolism), and cardiovascular magnetic resonance (fibrosis).

Main Results:

• Significant left ventricular dysfunction with myocardial viability often predicts improvement after revascularization.
• Recent randomized trials have introduced uncertainty regarding the benefit of viability testing.
• Current imaging techniques offer complementary information on myocardial status.

Conclusions:

• Myocardial viability testing remains significant in clinical decision-making for revascularization.
• Interpretation of recent randomized evidence should be cautious.
• Larger trials are needed to define the role of viability testing, especially cardiovascular magnetic resonance, in moderate-to-severe ischemic cardiomyopathy.