Anthracyclines are the gold standard adjuvant therapy for breast cancer patients but their use is limited by dose-dependent often irreversible cardiotoxicity.

To evaluate the interest of baseline echocardiographic parameters of left ventricular (LV) size and function to identify anthracycline-treated patients at high risk to develop cardiotoxicity in patients with low normal LV ejection fraction (LVEF).

We conducted a prospective longitudinal study in the cardio-oncology unit of Casablanca, the first cardio-oncology unit in Morocco. All the patients underwent echocardiography for pre-anthracycline assessment. LV volumes, LVEF, and peak longitudinal strain (GLS) were measured. Individuals were followed for cardiotoxicity and all-cause mortality over 23months (from January 2017 to November 2018)

Of 971patients, 522 (56,7%) had a resting LVEF of 50–60%. Average LVEF was 55±2%, global longitudinal strain (GLS) was −18.4±3.2% and LV end-diastolic volume (LVEDV) was 108±17mL. Twenty six patients (4,9%) presented cardiotoxicity: congestive heart failure (HF) in 19 patients, arterial hypertension in 1 patient, 2 pericardial effusion, 2 cases of arrhythmias, 1 case of 3rd degree atrioventricular block and 1 right ventricular dysfunction. Age, diabetes, obesity, GLS and LVEDV were all predictive of MACE (P=0.028, 0.017, 0.041, 0,038 and 0.014 respectively). Age and GLS were also predictive of overall mortality (P=0.021 and 0.003 respectively).

In patients treated with anthracyclines with an LVEF of 50-60%, both baseline EDV and GLS predict the development of cardiotoxicity. These results may enable select patients at higher risk of cardiotoxicity and thus initiate early cardioprotective medical therapy and a closer cardiac surveillance.