The hibernating myocardium: current concepts, diagnostic dilemmas, and clinical challenges in the post-STICH era

Abstract

A very large body of evidence--predominantly retrospective--suggests that revascularization is superior to optimal medical therapy in patients with a significant amount of 'hibernating' myocardium. Contemporary cardiological practice has embraced this standard of practice, as many centres worldwide place great emphasis upon the results of viability testing by non-invasive imaging techniques in determining the need for coronary revascularization. This practice has been challenged by the recent results of the Surgical Treatment for Ischaemic Heart Failure (STICH) trial, which suggested both lack of mortality benefit from revascularization and also from viability testing. In this review article, we have summarized the pathophysiology of hibernating myocardium, briefly discussed each of the non-invasive imaging modalities used in contemporary practice for detecting myocardial hibernation before critically appraising the prospective studies in this field, most importantly the main STICH trial and viability sub-study. STICH was clearly a complex trial but has not ended the question over the benefit of revascularization in ischaemic heart failure. Finally, we have suggested a possible methodology for an 'ideal trial' designed to evaluate the role of revascularization in such patients and also explored how viability testing should be used in clinical practice in the post-STICH era.

Dual-Contrast Molecular Imaging Allows Noninvasive Characterization of Myocardial Ischemia/Reperfusion Injury After Coronary Vessel Occlusion in Mice by Magnetic Resonance Imaging

“…28,29 Left ventricular ejection fraction (eg, ≤30%) is currently one of the major means for stratifying risk, for example, for predicting the development of sudden cardiac death. 30 However, a considerable number of patients with left ventricular ejection fraction >30% still suffer sudden cardiac death, and the consequence of classifying a high number of patients falsely as being at high risk is exerting pressure on our healthcare systems.…”

Exercise attenuates inflammation and limits scar thinning after myocardial infarction in mice

“…The final remodeling phase is characterized by fibrosis and LV dilatation (29,51,67). Recent clinical studies involving cardiac MRI have indicated that the amount of scarring in the thinned region of the heart inversely correlates with the improvement of regional and global systolic function after revascularization of such chronic ischemic areas (65), indicating that, in particular, the nonfibrotic tissue may consist of hibernating myocytes that become revitalized and functional upon the restoration of blood flow (64). In fact, regional wall thinning can be reversible upon revascularization, presumably by the reversal of hibernation, and this reverse remodeling is associated with a favorable prognosis in patients after MI (9,65).…”

Ischemic left ventricle systolic dysfunction: An evidence-based approach in diagnostic tools and therapeutics

“…Scars < 50% and > 75% have a high and low probability of functional recovery, respectively. 21 Although many studies point to the benefit of resonance and described tests in the management of ischemic cardiomyopathy, the lack of randomized controlled trials with hard clinical endpoints has not yet established the routine use of these methods in clinical practice.…”