Ivabradine for the Prevention of Anthracycline-Induced Cardiotoxicity in Female Patients with Primarily Breast Cancer: A Prospective, Randomized, Open-Label Clinical Trial.

Background and Objectives: Cancer therapy containing anthracyclines is associated with cancer-treatment-related cardiac dysfunction and heart failure (HF). Conventional cardioprotective medications can be frequently complicated by their blood-pressure-lowering effect. Recently, elevated resting heart rate was shown to independently predict mortality in patients with cancer. As a heart rate-lowering drug without affecting blood pressure, ivabradine could present an alternative management of anthracyclines-induced cardiotoxicity. Materials and Methods: This study aimed to investigate the probable protective effects of ivabradine in cancer patients with elevated heart rate (>75 beats per minute) undergoing anthracycline chemotherapy. Patients referred by oncologists for baseline cardiovascular risk stratification before anthracycline chemotherapy who met the inclusion criteria and had no exclusion criteria were randomly assigned to one of two strategies: ivabradine 5 mg twice a day (intervention group) or controls. Electrocardiogram, transthoracic echocardiogram with global longitudinal strain (GLS), troponin I (Tn I), and N-terminal natriuretic pro-peptide (NT-proBNP) were performed at baseline, after two and four cycles of chemotherapy and at six months of follow-up. The primary endpoint was the prevention of a >15% reduction in GLS. Secondary endpoints were effects of ivabradine on Tn I, NT-proBNP, left ventricular (LV) systolic and diastolic dysfunction, right ventricle dysfunction, and myocardial work indices. Results: A total of 48 patients were enrolled in the study; 21 were randomly assigned to the ivabradine group and 27 to the control group. Reduced GLS was detected 2.9 times less often in patients receiving ivabradine than in the control group, but this change was non-significant (OR [95% CI] = 2.9 [0.544, 16.274], p = 0.208). The incidence of troponin I elevation was four times higher in the control group (OR [95% CI] = 4.0 [1.136, 14.085], p = 0.031). There was no significant change in NT-proBNP between groups, but the increase in NT-proBNP was almost 12% higher in the control group (OR [95% CI] = 1.117 [0.347, 3.594], p = 0.853). LV diastolic dysfunction was found 2.7 times more frequently in the controls (OR [95% CI] = 2.71 [0.49, 15.10], p = 0.254). Patients in the ivabradine group were less likely to be diagnosed with mild asymptomatic CTRCD during the study (p = 0.045). No differences in right ventricle function were noted. A significant difference was found between the groups in global constructive work and global work index at six months in favour of the ivabradine group (p = 0.014 and p = 0.025). Ivabradine had no adverse effects on intracardiac conduction, ventricular repolarization, or blood pressure. However, visual side effects (phosphenes) were reported in 14.3% of patients. Conclusions: Ivabradine is a safe, well-tolerated drug that has shown possible cardioprotective properties reducing the incidence of mild asymptomatic cancer-therapy-induced cardiac dysfunction, characterised by a new rise in troponin concentrations and diminished myocardial performance in anthracycline-treated women with breast cancer and increased heart rate. However, more extensive multicentre trials are needed to provide more robust evidence.

Development of a Cardio-Oncology Service in Lithuania: Prediction, Prevention, Monitoring and Treatment of Cancer Treatment-Induced Cardiotoxicity.

Background: Advances in cancer therapy have dramatically improved outcomes for cancer pa-tients. However, cancer treatment can cause several cardiovascular (CV) complications, increasing cardiac mortality and morbidity in cancer patients and survivors. As a result, a new cardiology subspecialty­cardio-oncology (CO)­has been developed. The goals of CO are to understand the mechanism of the cardiotoxicity (CTX) of cancer therapies and invent the best monitoring and treatment strategies to improve the survival of cancer patients. Methods: We performed a retro-spective observational study reporting on the 6-year experience of the first CO service in Vilnius, Lithuania. Cancer patients were consulted by a single part-time specialist at Vilnius University Hospital. All new patients underwent blood tests, including cardiac biomarkers and advanced transthoracic echocardiogram (TTE) with stress protocol if indicated. During a follow-up, we evaluated the association of patient survival with such variables as age, gender, reasons for re-ferral, cancer location and stage, cardiovascular (CV) risk factors (RF), and rates and stage of CTX and treatment strategies. Results: 447 patients were consulted (70% females), and the median age was 64 years. Cardiovascular (CV) RF was common: 38.5% of patients had hypertension, almost 38% had dyslipidemia, 29% were obese, 10% were smokers, and 9% had diabetes. Nearly 26% of patients had a history of HF. Early biochemical cardiotoxicity was determined in 27%, early functional cardiotoxicity was seen in 17%, and early mixed cardiotoxicity­in 45% of referred patients treated with cardiotoxic cancer therapies. In addition, reduced left ventricular ejection fraction (LVEF) was found in 7% of patients. Beta-blockers (BB) were administered to 61.1% of patients, while angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARB) to 54.1% of patients. In addition, 18.3% of patients received loop diuretics and almost 12% mineralocorticoid receptor antagonists (MRA), respectively. A total of 143 patients died during the 6-year follow-up period. The leading cause of death was primarily cancer (92.3%). Only in 5.6% of patients, cardiovascular complications were reported as the cause of death, and 2.1% of deaths were due to the COVID−19 infection. We found that age (HR 1.020 [95% CI: (1.005−1.036)] p = 0.009); LV diastolic dysfunction (HR 1.731 [95% CI: 1.115−2.689] p = 0.015; NYHA stage II (HR 2.016 [95% CI: 1.242−3.272] p = 0.005; NYHA stage III (HR 3.545 [95% CI: 1.948−6.450] p < 0.001; kidney dysfunction (HR 2.085 [95% CI: 1.377−3.159] p = 0.001; previous cancer (HR 2.004 [95% CI: 1.219−3.295] p = 0.006); tumor progression (HR 1.853 [95% CI: 1.217−2.823] p = 0.004) and lung cancer (HR 2.907 [95%CI: 1.826−4.627] p < 0.001) were statistically significantly associated with the increased risk of all-cause death. Conclusions: CO is a rapidly growing subspecialty of cardiology that aims to remove cardiac disease as a barrier to effective cancer treatment by preventing and reversing cardiac damage caused by cancer therapies. Establishing a CO service requires a cardiologist with an interest in oncology. Continuous education, medical training, and clinical research are crucial to success. Age, previous cancer, tumor progression, kidney dysfunction, left ventricular diastolic dysfunction, and NYHA stages were associated with increased mortality.