Patients in the treatment group received a median carvedilol dose of 18.4 mg/day. The primary endpoint of cardiotoxicity, defined as a decrease in left ventricular ejection fraction (LVEF) of at least 10% at 6 months, occurred in 15% of carvedilol patients and 14% placebo patients, a nonsignificant difference. No significant differences occurred in diastolic dysfunction or in B-type natriuretic peptide (BNP) levels at 6 weeks, 12 weeks, or 24 weeks between the groups.
However, carvedilol patients showed significantly reduced troponin 1 levels compared with placebo, which suggests protection against myocardial injury, Dr. Avila said.
“In short follow up, we can see cardiotoxicity appearing, and we know we have to treat it promptly to prevent cardiac events,” she said.
Dr. Avila and colleagues identified 200 women older than 18 years with HER2-negative breast cancer tumor status and normal left ventricular ejection fraction. The patients were undergoing chemotherapy with 240 mg/m2 of anthracycline and were randomized to treatment with carvedilol or a placebo. Baseline characteristics were similar between the two groups.