Cardiovascular MR to access myocardial viability in chronic ischaemic LV dysfunction

eart failure has become a major problem in clinical cardiology, with recent estimations showing that 4.9 million patients in the USA have chronic heart failure, with 550 000 new patients diagnosed annually, resulting in 970 000 hospitalisations. 1 It appears that coronary artery disease is the underlying cause of heart failure in .70% of patients. 1The available therapeutic options include optimised medical treatment, heart transplantation, revascularisation (with optional left ventricular (LV) restoration and/or mitral valve repair) and cardiac resynchronisation therapy.Currently, substantial effort is invested in the development of gene and cell therapy for treatment of heart failure.In daily clinical practice, the choice is frequently between medical treatment and revascularisation.From this perspective, assessment of viability is important to guide management of patients with ischaemic LV dysfunction; patients with viable myocardium may improve in LV function after revascularisation, whereas patients with only scar tissue will not improve.In view of the increased risk for (peri-) operative complications, a pre-operative evaluation for myocardial viability is thus warranted, to select the patients who may benefit from surgery.Currently, many techniques are available for identification of dysfunctional but viable myocardium.w1 The most frequently used techniques in the clinical setting include nuclear imaging with positron emission tomography (PET) and single photon emission computed tomography (SPECT) to assess myocardial metabolism, perfusion, cell membrane and mitochondrial intactness; and echocardiographic imaging using dobutamine stress to assess contractile reserve/ischaemia or contrast agents to assess myocardial perfusion.More recently cardiac magnetic resonance (CMR) has become popular for the assessment of myocardial viability.This technique has an excellent spatial resolution and is currently the only imaging modality that allows distinction between transmural and subendocardial processes.Various techniques with CMR provide information on myocardial viability; these will be discussed extensively in this article.Besides assessment of viability, CMR provides for the surgeon additional information needed to select the optimal surgical strategy, including information on LV function, LV volumes, the presence of LV aneurysms (which need LV aneurysmectomy), and ischaemic mitral regurgitation (which require mitral valve repair in terms of restrictive annuloplasty).This article discusses the value of CMR (in particular the different CMR techniques to assess viability) for the evaluation of patients with ischaemic cardiomyopathy.Before entering this discussion, some definitions of viability and the clinical relevance of viability assessment are addressed.