High-sensitivity cardiac troponin I-guided combination angiotensin receptor blockade and beta blocker therapy to prevent anthracycline cardiotoxicity: the Cardiac CARE RCT

Background Anthracycline-induced cardiotoxicity has a variable incidence, and the development of left ventricular dysfunction is preceded by rises in plasma cardiac troponin concentrations. Beta-adrenergic receptor blocker and renin-angiotensin-system inhibitor therapies have been associated with modest cardioprotective effects in unselected patients receiving anthracycline chemotherapy. Methods In a multicentre prospective randomised open-label blinded end-point trial, patients with breast cancer and non-Hodgkin lymphoma receiving anthracycline chemotherapy underwent plasma high-sensitivity cardiac troponin concentration monitoring and cardiac magnetic resonance imaging before and 6 months after anthracycline treatment. Randomised controlled trial – patients at high risk of cardiotoxicity (plasma cardiac troponin I concentrations in the upper tertile during chemotherapy) were randomised to standard care plus cardioprotection (combination carvedilol and candesartan therapy) or standard care alone. The primary end point was 6-month change in left ventricular ejection fraction. Prognostic cohort study – in low-risk non-randomised patients with plasma cardiac troponin I concentrations in the lower two tertiles, we hypothesised the absence of a 6-month change in left ventricular ejection fraction (± 2%). Results Between October 2017 and June 2021, 175 patients (mean age 53 years; 87% female; 71% breast cancer) were recruited. Patients randomised to cardioprotection (n = 29) or standard care (n = 28) had mean left ventricular ejection fractions of 65.7 ± 6.6% and 64.9 ± 5.9%, respectively, at 6 months. Twenty patients (68.9%) were adherent to cardioprotection therapy at 6 months. Adverse events were more commonly reported in the cardioprotection group, with 71.4% of patients having at least one adverse event compared with 12.7% non-randomised and 10.3% standard care patients. After adjusting for age, pre-treatment left ventricular ejection fraction and planned anthracycline dose, the estimated mean percentage-point difference in 6-month left ventricular ejection fraction between the cardioprotection and standard care groups was –0.4% (95% confidence interval –3.59 to 2.85%; p = 0.82). In low-risk non-randomised patients, baseline and 6-month left ventricular ejection fractions were 69.3 ± 5.7% and 66.4 ± 6.3%, respectively (estimated mean difference 2.9%, 95% confidence interval 1.45 to 4.28%; p = 0.92, not equivalent). The main secondary objective of demonstra