Cardiovascular magnetic resonance characterisation of anthracycline cardiotoxicity in adults with normal left ventricular ejection fraction.

BACKGROUND

Anthracycline therapy may lead to changes in cardiac structure and function not detectable by solely evaluating left ventricular ejection fraction (LVEF).

OBJECTIVES

We hypothesized that cardiovascular magnetic resonance (CMR) would identify structural and functional myocardial abnormalities in anthracycline-treated cancer survivors with normal LVEF, compared to a matched control population.

METHODS

Forty-five cancer survivors (56 ± 16 yrs., 60% female) with normal LVEF (59.5 ± 4.1%) were studied a median of 11 months (range 3-36) following administration of 237 ± 83 mg/m2 anthracycline, and compared with forty-five healthy control subjects of similar age and sex (53 ± 16 yrs., 60% female) with normal LVEF (60.8 ± 2.4%) using 1.5 T CMR.

RESULTS

Significantly smaller indexed left ventricular mass (45.6 ± 8.7 vs 50.3 ± 10.1 g/m2, p = 0.02) and indexed myocardial cell volume (30.5 ± 5.7 vs 34.8 ± 7.2 ml/m2, p = 0.002) were evident in cancer survivors and the latter was inversely associated with cumulative anthracycline dose (r = -0.31, p = 0.02). Surrogate CMR markers of myocardial fibrosis were significantly increased in cancer survivors (native myocardial T1: 1021 ± 40 vs 996 ± 35 ms, p = 0.002; extracellular volume: 29.5 ± 4.5 vs 27.4 ± 2.3%, p = 0.006). CMR-derived feature-tracking global longitudinal strain (GLS) was significantly impaired in cancer survivors (2D GLS -18.3 ± 2.6 vs -20.0 ± 2.0%, p < 0.001; 3D GLS -14.5 ± 2.3 vs -16.4 ± 2.6%, p < 0.001). Parameters exhibited good to excellent (ICC = 0.86-0.98) inter- and intra-observer reproducibility.

CONCLUSIONS

Anthracycline-treated cancer survivors with normal LVEF have significant perturbations of LV mass, myocardial cell volume, native myocardial T1, ECV, CMR-derived 2D and 3D GLS, compared to controls, with good to excellent levels of inter- and intra-observer reproducibility.