CMR reveals myocardial damage from cardiotoxic oncologic therapies in breast cancer patients.

Background: Breast cancer is a common and increasingly treatable disease. However, survivors have a significantly elevated risk of cardiac events afterwards. This study aimed to characterise cardiac changes during cardiotoxic cancer therapy using cardiovascular magnetic resonance (CMR) imaging.

Methods: This study involved 34 patients with histologically proven breast cancer and planned cardiotoxic therapy. All patients underwent CMR before starting therapy, and 6 and 12 months thereafter. The CMR protocol included volumetric and functional analyses, parametric mapping, and deformation analysis using feature tracking. As the control group, 10 healthy female volunteers were scanned using the same protocol.

Results: With therapy, there was a significant reduction of left ventricular and right ventricular ejection fractions (both p < 0.05) without reaching pathologic values. Left ventricular radial (p = 0.008), circumferential (p = 0.010), and longitudinal strain (p = 0.036) were also reduced at follow-up. In the parametric mapping, there was a significant increase in native T1 time (start: 1037 ± 41 ms vs. 6 months: 1068 ± 51 ms vs. 12 months: 1017 ± 57 ms, p < 0.001) and T2 time (start: 55 ± 4 ms vs. 6 months: 59 ± 3 ms vs. 12 months: 57 ± 3 ms, p = 0.001), with unchanged extracellular volume and relative late gadolinium enhancement. Twelve months after cancer diagnosis, the breast cancer patients exhibited significant impairments in left ventricular global radial (p = 0.001), circumferential (p = 0.001), and longitudinal strain (p = 0.002) and T2 time (p = 0.008) compared to the healthy controls.

Discussion: Breast cancer patients receiving cardiotoxic chemotherapy show persistent deterioration in left ventricular strain values. This is accompanied by inflammatory changes in non-invasive tissue characterisation. Larger studies with longer follow-up periods are needed to identify patients at risk and establish preventive and therapeutic approaches.