IJCS | Volume 32, Nº1, January/ February 2019

77 Table 3 - Guidelines, Appropriate Use Criteria and Position Statements for the use of viability imaging in patients with ischemic heart failure. With permission from Wiefels et al., Curr Cardiovasc Imaging Rep. 73 Recommendation Grade Level Organization Nuclear imaging for assessment of myocardial viability for consideration of revascularization in patients with CAD and LV dysfunction who do not have angina I B ACC/AHA/ASNC Radionuclide Imaging 2003 44 Cardiac PET and CMR should be used in the evaluation and prognostication of patients with ICM and LV dysfunction I B CCS/CAR/CANM/CNCS/ Can SCMR 2007 47 Noninvasive imaging to detect myocardial ischemia /viability in HF and CAD IIa C ACCF/AHA CHF 2013 48 Viability assessment is reasonable before revascularization in HF patients with CAD IIa B ACCF/AHA CHF 2013 48 Non-invasive stress imaging (CMR, echo, SPECT, PET) may be considered for the assessment of myocardial ischemia and viability in patients with HF and CAD (considered suitable for coronary revascularization) before the decision on revascularization. IIb B ESC CHF 2016 44 Myocardial viability testing should be considered in patients with ischemic CM and reduced LV EF eligible for revascularization Appropriate use score: 9 AACF/ASNC/ACR/ASE/ SCCT/SCMR/ SNM 2009 45 Erthal et al. Myocardial viability: from PARR-2 to IMAGE HF - current evidence and future directions Int J Cardiovasc Sci. 2019;32(1)70-83 Review Article gadolinium enhanced MRI which are more sensitive than contractile reserve. 5,27,53 4. Renal failure (GFR < 30) or implanted devices – avoid MRI. 5. Left main coronary artery disease or severe proximal 3-vessel disease – avoid dobutamine. 6. Equivocal results on another viability test or negative results on another viability test, where certainty is needed to completely rule [in or] out viability – consider FDG PET or MRI as highly sensitive methods. 5,27,51,53 Future directions The IMAGE HF (Imaging Modalities to Assist with Guiding therapy in the Evaluation of patients with Heart Failure) project includes a group of clinical trials, one of which is theAIMI-HF trial (Alternative ImagingModalities in Ischemic Heart Failure) (NCT01288560) 54 (Figure 7). AIMI-HF is a multicenter randomized trial and registry study involving centers from Canada, United States, Finland, Brazil and Argentina. It compares the impact of standard of care investigation (SPECT) versus advanced imaging (PET and MRI) for viability and ischemia assessment. Composite outcomes are cardiac death, resuscitated cardiac arrest, MI and cardiac hospitalization. In cases where the patient is not randomized to one or the other arm, they are included in a clinical registry. 54 This studywill help us understand the impact of the advanced cardiac imaging modalities for the viability assessment and their impact on patient outcome. PET andMRI viability targets are different andmay be complementary. The availability of PET/MRI scanners is growing, and an initial study suggests the feasibility of simultaneous assessment of FDG uptake and delayed enhancement. 30 Indeed, analysis per segment showed increased accuracy for predictingwall motion recovery in segments of accordance between themodalities. 30 Further trials are needed to show its reproducibility. Cardiac biomarkers (troponin T and brain natriuretic peptide) are used for patient assessment and as prognostic tools. 54–58 Arecent study has demonstrated their correlation with hibernating myocardium independently of ejection fraction, age and kidney function (Figure 8). 58 Future paradigm shifts in the work-up of patients with ischemic HF could involve the use of biomarkers to optimize image-guided therapy or in some cases be independent of imaging to decide revascularization therapy, but this theoretical approach requires specific study. Hibernatingmyocardium is a substrate for arrhythmia and increases the risk of sudden cardiac death, possibly due to the sympathetic innervation inhomogeneity. 58–62 The ADMIRE trial has used MIBG SPECT to define altered sympathetic neuronal (SN) function in patients with HF, demonstrating higher risk in patients with