Electrocardiography changes during adjuvant breast cancer therapy: incidence and risk factors

Abstract

Background/aim: Breast cancer survivors have a higher cardiovascular morbidity/mortality rate, when compared with healthy age-matched general population. Electrocardiography (ECG) changes have been found to be associated with chemo- and radiation therapy. In the present study we investigated changes in ECG patterns following modern adjuvant therapy for breast cancer.

Patients and methods: A standard 12-lead electrocardiogram was recorded at rest three times (prior and after adjuvant therapy) and retrospectively analyzed in 414 breast cancer patients, who participated in the open prospective phase III randomized trial (BREX) of exercise training 2005-2007.

Results: New electrocardiographic changes in the T-wave or ST-segment (depression or elevation) after the adjuvant therapy were recorded in 49 patients (13%). In multivariate analyses, hypertension treated with anti-hypertensive medication was the only significant factor associated with irreversible ECG changes (OR=4.71; 95% CI=1.36-16.38; p=0.015).

Conclusion: New irreversible pathological electrocardiographic changes, which acquired during the adjuvant therapy, had a clear relationship with hypertension This patients subgroup needs to be studied further.

Keywords: Breast cancer; adjuvant therapy; cardiotoxicity; electrocardiography (ECG); radiotherapy.