Cardiotoxicity in low-to-moderate cardiovascular risk patients undergoing anti-HER2 therapy: a prospective cardiac magnetic resonance study

Abstract Background The study aimed to investigate cardiotoxicity among individuals undergoing anti-human epidermal growth factor receptor 2 (HER2) therapy with a low-to-moderate risk of cardiovascular complications. Cardiac magnetic resonance (CMR) imaging was employed in the investigation. Patients and methods HER2-positive breast cancer patients who underwent CMR examinations both before and during therapy (first follow-up: 3-5 months; second follow-up: 6-12 months) between January 2021 and December 2022 were prospectively included. Each patient was evaluated for the risk of cardiovascular toxicity. Results Thirty-five HER2-positive breast cancer patients were included (48.86 ± 10.34 years). Eighty-nine percent of patients had low cardiovascular toxicity risk, and 11% had moderate cardiovascular toxicity risk. At follow-up CMR, nine (25.71%) patients developed cardiac dysfunction. At follow-up 1, there was a notable decrease in left ventricular ejection fraction, stroke volume index, cardiac output index, and absolute strain values, accompanied by higher T1 and T2 values as well as end-systolic volume index compared to baseline (p ≤ 0.002). At follow-up 2, the T1 and T2 values recovered to near baseline. The cardiac output index exhibited a continuous decline (p ≤ 0.022), while other variables were similar (p > 0.05). Furthermore, at follow-up 1, the T1 value displayed a marked increase in patients with 1-3 points in cardiovascular toxicity risk factors compared to those with no risk factors (p ≤ 0.043). Conclusions It is common for patients with low-to-moderate cardiovascular risk to experience early cardiotoxicity during anti-HER2 therapy. T1 mapping was a valuable approach for quantifying the specific extent of subtle tissue damage.