Echo-loop of subclinical cardiovascular toxicity in women associated with HER2-positive breast cancer therapy

Abstract

Aim. To assess the incidence and timing of subclinical cardiac dysfunction associated with therapy for HER2-positive locally advanced or metastatic breast cancer, and to analyze the difference in time from significant reduction in left ventricular (LV) global longitudinal strain (GLS) to significant reduction in LV ejection fraction (LVEF) (cardiotoxicity "echo-loop").Material and methods. A total of 187 women 58±11 years without baseline cardiac dysfunction with verified HER2-positive locally advanced or metastatic breast cancer who received sequential adjuvant therapy with doxorubicin+cyclophosphamide, docetaxel+trastuzumab and trastuzumab monotherapy were followed up in 4 centers in four countries within 12 months with regular (every 3 weeks) speckle-tracking echocardiographic monitoring.Results. Subclinical cardiac dysfunction associated with breast cancer therapy (CTRCD) appears in each block of therapy after the first course. Its frequency increases significantly after each subsequent course compared to the previous one. By the end of the 4th course in each block of therapy, subclinical CTRCD is noted from 24,6% (almost every 4th patient in the chemotherapy block) to 32,6-33,7% (almost every 3rd patient in the chemotherapy and targeted therapy blocks). In 24 out of 25 cases of severe subclinical CTRCD (96%) with a fall in LVEF <40%, a decrease in LV GLS >15% was preceded. The time difference from a decrease in LV GLS to a decrease in LVEF <40% (cardiotoxicity "echo loop”) ranges from 5 to 16 weeks depending on the cancer therapy option.Conclusion. Until recently, the period of identified moderate subclini­cal cardiac dysfunction was not used to prescribe therapy for the pre­vention and treatment of cardiotoxicity. Enhanced speckle-tracking echo­cardiographic monitoring may reduce the incidence of severe sub­clinical and overt clinical cardiac dysfunction. Guidelines for car­diotoxicity monitoring should be reviewed to reduce the incidence of se­vere cardiac complications of cancer therapy.