Is cardiac magnetic resonance imaging assessment of myocardial viability useful for predicting which patients with impaired ventricles might benefit from revascularization?

Before revascularizing a weakened heart, the decisive question is whether the muscle can recover. This structured evidence review weighs cardiac MRI’s answer.

The metric is late gadolinium enhancement, which marks scar. The review’s synthesis of ten studies found an inverse relationship that’s clinically usable: the more scar an MRI shows in a segment of muscle, the less likely that segment is to regain contraction after blood flow is restored. Little scar, good odds; transmural scar, futility.

The practical takeaway is decision support — MRI can identify which impaired ventricles hold viable, recoverable muscle and which don’t, steering patients toward or away from a risky procedure. The resistance comes from reliance on echocardiography or SPECT and uneven access to cardiac MRI.

We rate the evidence moderate: a methodologically sound “best evidence” review, but built on ten heterogeneous studies rather than new prospective data. Its clinical significance is moderate — meaningful for the specific population with ischemic cardiomyopathy facing a revascularization decision, where getting viability right directly changes outcomes.