Myocardial External Efficiency
Simple, automated and reproducible estimation of Myocardial External Efficiency (MEE), the ratio of energy consumed by the heart and the mechanical work performed by the heart, is a valuable tool for characterizing cardiomyopathies and for evaluating treatment response.
11C-acetate has been used for decades to estimate myocardial energy consumption and, in combination with mass and work measurements from MRI or ECHO, the MEE. This multi-scan approach is, however, cumbersome and costly and can introduce errors as hemodynamic conditions may change between sessions.
Automatic Calculation of MEE from a single 11C-acetate PET-scan
Recent work by the aQuant Team has shown that both myocardial mass and external work can be measured directly from the same 11C-acetate scan used for measuring the energy consumption. This allows for measurement of MEE from a single 11C-acetate PET-scan. Furthermore, this can be done in an automated and highly reproducible fashion.
Using this approach protocol duration and cost as well as patient burden are greatly reduced.
The method is implemented in the aQuant Research package.
aQuant Research package
The aQuant Research package is a tool for non-15O-water cardiac applications and is not part of the commercial aQuant application. It is available for non-commercial partners collaborating with the aQuant Team. Please, email research(at)aquantsoft.com to reach out to the team.
Review on the application of MEE:
Sörensen, J. et al (2019). Myocardial Efficiency: A Fundamental Physiological Concept on the Verge of Clinical Impact. JACC: Cardiovascular Imaging, DOI: 10.1016/j.jcmg.2019.08.030
On the method:
Harms, H, Stubkjær Hansson, NH, Kero, T, Baron, T, Tolbod, LP, Kim, WY, Frøkiær, J, Flachskamp, FA, Wiggers, H & Sørensen, J (2018). Automatic calculation of myocardial external efficiency using a single 11C-acetate PET scan. Journal of Nuclear Cardiology, s. 1-8. DOI: 10.1007/s12350-018-1338-0
Hansson, N.H., Harms, H.J., Kim, W.Y., Nielsen, R.,Tolbod, L.P., Frøkiær, J., Bouchelouche, K., Poulsen, S.H., Wiggers, H., Parner, E.T., Sörensen, J (2018). Test–retest repeatability of myocardial oxidative metabolism and efficiency using standalone dynamic 11C-acetate PET and multimodality approaches in healthy controls. J. Nucl. Cardiol. (2018). DOI: 10.1007/s12350-018-1302-z
Harms, H. J., Hansson, N. H. S., Tolbod, L. P., Kim, W. Y., Jakobsen, S., Bouchelouche, K., ... Sörensen, J. (2016). Automatic extraction of myocardial mass and volumes using parametric images from dynamic nongated PET. Journal of Nuclear Medicine, 57(9), 1382-87. DOI: 10.2967/jnumed.115.170613
Harms, H., Tolbod, L. P., Hansson, N. H. S., Kero, T., Orndahl, L. H., Kim, W. Y., ... Sørensen, J. (2015). Automatic extraction of forward stroke volume using dynamic PET/CT: a dual-tracer and dual-scanner validation in patients with heart valve disease. EJNMMI physics, 2(1), .. DOI: 10.1186/s40658-015-0133-0
Hansson, N. H., Tolbod, L., Harms, H., Wiggers, H., Kim, W. Y., Søvsø Szocska Hansen, E., ... Sørensen, J. (2016). Evaluation of ECG-gated [(11)C]acetate PET for measuring left ventricular volumes, mass, and myocardial external efficiency. Journal of Nuclear Cardiology. DOI: 10.1007/s12350-015-0331-0
Some examples of the use of MEE:
Nielsen, R., Møller, N., Gormsen, L. C., Tolbod, L. P., Hansson, N. H., Sorensen, J., ... Wiggers, H. (2019). Cardiovascular Effects of Treatment with the Ketone Body 3-Hydroxybutyrate in Chronic Heart Failure Patients. Circulation. DOI: 10.1161/CIRCULATIONAHA.118.036459
Clemmensen, T. S., Soerensen, J., Hansson, N. H., Tolbod, L. P., Harms, H. J., Eiskjær, H., ... Poulsen, S. H. (2018). Myocardial Oxygen Consumption and Efficiency in Patients With Cardiac Amyloidosis. Journal of the American Heart Association, 7(21), e009974. DOI: 10.1161/JAHA.118.009974
Hansson, N. H. S., Sörensen, J., Harms, H. J., Kim, W. Y., Nielsen, B. R. R., Tolbod, L. P., ... Wiggers, H. (2017). Myocardial Oxygen Consumption and Efficiency in Aortic Valve Stenosis Patients With and Without Heart Failure. Journal of the American Heart Association, 6(2). DOI: 10.1161/JAHA.116.004810
Parbhudayal RY, Harms HJ, Michels M, van Rossum AC, Germans T, van der Velden J. (2020). Increased Myocardial Oxygen Consumption Precedes Contractile Dysfunction in Hypertrophic Cardiomyopathy Caused by Pathogenic TNNT2 Gene Variants. Journal of the American Heart Association. DOI: 10.1161/JAHA.119.015316