AUTHOR=Macnaught Gillian , Oikonomidou Olga , Rodgers Christopher T. , Clarke William , Cooper Annette , McVicars Heather , Hayward Larry , Mirsadraee Saeed , Semple Scott , Denvir Martin A. 

TITLE=Cardiac Energetics Before, During, and After Anthracycline-Based Chemotherapy in Breast Cancer Patients Using 31P Magnetic Resonance Spectroscopy: A Pilot Study

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2021.653648

DOI=10.3389/fcvm.2021.653648

ISSN=2297-055X

ABSTRACT=<p><bold>Purpose:</bold> To explore the utility of phosphorus magnetic resonance spectroscopy (<sup>31</sup>P MRS) in identifying anthracycline-induced cardiac toxicity in patients with breast cancer.</p><p><bold>Methods:</bold> Twenty patients with newly diagnosed breast cancer receiving anthracycline-based chemotherapy had cardiac magnetic resonance assessment of left ventricular ejection fraction (LVEF) and <sup>31</sup>P MRS to determine myocardial Phosphocreatine/Adenosine Triphosphate Ratio (PCr/ATP) at three time points: pre-, mid-, and end-chemotherapy. Plasma high sensitivity cardiac troponin-I (cTn-I) tests and electrocardiograms were also performed at these same time points.</p><p><bold>Results:</bold> Phosphocreatine/Adenosine Triphosphate did not change significantly between pre- and mid-chemo (2.16 ± 0.46 vs. 2.00 ± 0.56, <italic>p</italic> = 0.80) and pre- and end-chemo (2.16 ± 0.46 vs. 2.17 ± 0.86, <italic>p</italic> = 0.99). Mean LVEF reduced significantly by 5.1% between pre- and end-chemo (61.4 ± 4.4 vs. 56.3 ± 8.1 %, <italic>p</italic> = 0.02). Change in PCr/ATP ratios from pre- to end-chemo correlated inversely with changes in LVEF over the same period (<italic>r</italic> = −0.65, <italic>p</italic> = 0.006). Plasma cTn-I increased progressively during chemotherapy from pre- to mid-chemo (1.35 ± 0.81 to 4.40 ± 2.64 ng/L; <italic>p</italic> = 0.01) and from mid- to end-chemo (4.40 ± 2.64 to 18.33 ± 13.23 ng/L; <italic>p</italic> = 0.001).</p><p><bold>Conclusions:</bold> In this small cohort pilot study, we did not observe a clear change in mean PCr/ATP values during chemotherapy despite evidence of increased plasma cardiac biomarkers and reduced LVEF. Future similar studies should be adequately powered to take account of patient drop-out and variable changes in PCr/ATP and could include T1 and T2 mapping.</p>