Genetic Variability of Antioxidative Mechanisms and Cardiotoxicity after Adjuvant Radiotherapy in HER2-Positive Breast Cancer Patients

Table 2

Markers of cardiac side effects of breast cancer therapy.

Marker	Category/Unit	(%)
Initial LVEF	%	65 (60-70)
Absolute change in LVEF	%	3 (-3 do 9)
LVEF reduction	No	92 (91.1)
	Yes	9 (8.9)
NT-proBNP	ng/l	90 (56-157)
NT-proBNP	<125 ng/l	65 (64.4)
	≥125 ng/l	36 (35.6)
NYHA	Class 1	84 (83.2)
	Class 2	17 (16.8)

median (25%-75%). LVEF: left ventricular ejection fraction; NT-proBNP: N-terminal pro B-type natriuretic peptide; NYHA: New York Heart Association. Absolute change in LVEF was calculated as the difference between LVEF after completed adjuvant radiotherapy and trastuzumab treatment, and LVEF before radiotherapy. LVEF reduction was classified as a decrease of LVEF for ≥10% or a final value of LVEF <50%.