Biomarkers and Strain Echocardiography for the Detection of Subclinical Cardiotoxicity in Breast Cancer Patients Receiving Anthracyclines

The optimal surveillance and management strategies for breast cancer patients receiving anthracycline therapy are limited by our incomplete understanding of the role of biomarkers heralding the onset of cardiotoxicity. The purpose of this study was to determine whether there is a temporal correlation between cardiac biomarkers and subclinical left ventricular dysfunction in breast cancer patients receiving anthracycline chemotherapy. Thirty-one females between 46 and 55 years old with breast cancer treated with anthracycline chemotherapy were prospectively enrolled. Cardiac biomarkers were correlated with echocardiography with speckle tracking at baseline, post-anthracycline therapy, and 6 months post-anthracycline chemotherapy. Subclinical cardiotoxicity was defined as ≥ 10% reduction in global longitudinal strain (GLS). There was a relative reduction in left ventricular ejection fraction (LVEF) ≥ 10% in 5/30 (17%) and 7/27 (26%) patients post-anthracycline therapy and 6 months post-anthracycline therapy, respectively. Subclinical cardiotoxicity was noted in 8/30 (27%) and 10/26 (38%) patients post-anthracycline and 6 months post-anthracycline therapy, respectively. Baseline N-terminal pro B-type natriuretic peptide (NT-proBNP) was the strongest predictor of LVEF (ρ = -0.45; p = 0.019), with post-therapy NT-proBNP values illustrating similar predictive value (ρ = -0.40; p = 0.038). Interim changes in suppression of tumorigenicity 2 (ST2) and galectin-3 correlated with a 6-month change in LVEF (ρ = -0.48; p = 0.012 and ρ = -0.45; p = 0.018, for ST2 and galectin-3, respectively). Changes in galectin-3 from baseline to mid-therapy paralleled changes in GLS. NT-proBNP, ST2, and galectin-3 correlate with reduced LVEF among breast cancer patients receiving anthracycline therapy. Additional trials focusing on a cardiac biomarker approach may provide guidance in the early diagnosis and management of anthracycline-induced cardiotoxicity.

Evaluation of Cardiotoxic Effects of Anthracyclines by Tissue Doppler Imaging in Survivors of Childhood Cancer

BACKGROUND

Childhood cancer survivors (CCSs) are at risk for anthracycline-induced cardiotoxicity which tends to be more prominent long after completion of the chemotherapy. The aim of this study was to examine echocardiographic parameters of anthracycline-induced subclinical cardiotoxicity in children who had received chemotherapy.

MATERIALS AND METHODS

A cross-sectional single-center study was conducted in a tertiary level university hospital in Eskisehir, Turkey. A total of 50 CCSs and 40 healthy peers were included. The CCSs were divided into 3 subgroups according to cumulative anthracycline dose (100-200 mg/m2, 201-299 mg/m2, and ≥ 300 mg/m2). Biventricular cardiac examination was performed with conventional echocardiography and tissue Doppler echocardiography imaging (TDI).

RESULTS

The mean duration from termination of chemotherapy to echocardiographic assessment was 3.9 ± 2.2 years. The mean age of the CCSs was 11.6 ± 3.9 years. TDI-derived mitral annular isovolumetric relaxation time (IVRT) and myocardial performance index (MPI) were higher in the high-dose group of CCSs than in controls (P = .006, P = .007, P < .001, P = .0014, respectively). IVRT was also higher in patients with ≥ 300 mg/m2 cumulative dose than in those with < 200 mg/m2 (P = .007). TDI-derived mitral annular MPI and IVRT were significantly associated with cumulative anthracycline dose (r = 0.288, P = .006, r = 0.340, P = .001).

CONCLUSION

A cumulative anthracycline dose > 300 mg/m2 may lead to subclinical cardiotoxicity, and is therefore a potential risk factor for late onset cardiac failure. TDI-derived MPI can be a sensitive tool to reveal subtle signs of myocardial damage, which may facilitate implementation of preventive therapies for patients suspected to be at risk.

Prodrug of ICRF-193 provides promising protective effects against chronic anthracycline cardiotoxicity in a rabbit model in vivo

The anthracycline (ANT) anticancer drugs such as doxorubicin or daunorubicin (DAU) can cause serious myocardial injury and chronic cardiac dysfunction in cancer survivors. A bisdioxopiperazine agent dexrazoxane (DEX) has been developed as a cardioprotective drug to prevent these adverse events, but it is uncertain whether it is the best representative of the class. The present study used a rabbit model of chronic ANT cardiotoxicity to examine another bisdioxopiperazine compound called GK-667 (meso-(butane-2,3-diylbis(2,6-dioxopiperazine-4,1-diyl))bis(methylene)-bis(2-aminoacetate) hydrochloride), a water-soluble prodrug of ICRF-193 (meso-4,4'-(butan-2,3-diyl)bis(piperazine-2,6-dione)), as a potential cardioprotectant. The cardiotoxicity was induced by DAU (3 mg/kg, intravenously, weekly, 10 weeks), and GK-667 (1 or 5 mg/kg, intravenously) was administered before each DAU dose. The treatment with GK-667 was well tolerated and provided full protection against DAU-induced mortality and left ventricular (LV) dysfunction (determined by echocardiography and LV catheterization). Markers of cardiac damage/dysfunction revealed minor cardiac damage in the group co-treated with GK-667 in the lower dose, whereas almost full protection was achieved with the higher dose. This was associated with similar prevention of DAU-induced dysregulation of redox and calcium homeostasis proteins. GK-667 dose-dependently prevented tumor suppressor p53 (p53)-mediated DNA damage response in the LV myocardium not only in the chronic experiment but also after single DAU administration. These effects appear essential for cardioprotection, presumably because of the topoisomerase IIβ (TOP2B) inhibition provided by its active metabolite ICRF-193. In addition, GK-667 administration did not alter the plasma pharmacokinetics of DAU and its main metabolite daunorubicinol (DAUol) in rabbits in vivo. Hence, GK-667 merits further investigation as a promising drug candidate for cardioprotection against chronic ANT cardiotoxicity.

Effect of anthracycline therapy on myocardial function and markers of fibrotic remodelling in childhood cancer survivors

AIMS

Anthracyclines are a cornerstone of paediatric cancer treatment. We aimed to quantify myocardial cardiac magnetic resonance (CMR) native T1 (NT1) and extracellular volume fraction (ECV) as markers of fibrosis in a cohort of childhood cancer survivors (CCS).

METHODS AND RESULTS

A cohort of CCS in remission underwent CMR T1 mapping. Diastolic function was assessed by echocardiography. Results were compared to a cohort of normal controls of similar age and gender. Fifty-five CCS and 46 controls were included. Both groups had similar mean left ventricular (LV) NT1 values (999 ± 36 vs. 1007 ± 32 ms, P = 0.27); ECV was higher (25.6 ± 6.9 vs. 20.7 ± 2.4%, P = 0.003) and intracellular mass was lower (37.5 ± 8.4 vs. 43.3 ± 9.9g/m2, P = 0.02) in CCS. The CCS group had lower LV ejection fraction (EF) and LV mass index with otherwise normal diastolic function in all but one patient. The proportion of subjects with elevated ECV compared to controls did not differ between subgroups with normal or reduced LV EF (22% vs. 28%; P = 0.13) and no correlations were found between LVEF and ECV. While average values remained within normal range, mitral E/E' (6.6 ± 1.6 vs. 5.9 ± 0.9, P = 0.02) was higher in CCS. Neither NT1 nor ECV correlated with diastolic function indices or cumulative anthracycline dose.

CONCLUSIONS

There is evidence for mild diffuse extracellular volume expansion in some asymptomatic CCS; myocyte loss could be part of the mechanism, accompanied by subtle changes in systolic and diastolic function. These findings suggest mild myocardial damage and remodelling after anthracycline treatment in some CCS which requires continued monitoring.

Cardiotoxicity After Anthracycline Chemotherapy for Childhood Cancer in a Multiethnic Asian Population

Background: Anthracyclines are widely used to treat childhood cancers; however, they cause cardiotoxicity. To address the paucity of clinical data from Asian populations, this study investigated the epidemiology of pediatric anthracycline-induced cardiotoxicity, during and after chemotherapy, in a multiethnic Asian population. Procedure: This was a single-center, retrospective analysis of 458 anthracycline-treated pediatric oncology patients at KK Women's and Children's Hospital, a tertiary children's hospital in Singapore from 2005 through 2015. We investigated cardiotoxicity (defined as left ventricular fractional shortening <28% on echocardiography) and its risk factors using univariate logistic regression as well as survival estimates through the Kaplan-Meier method to compare survival distribution between patients with and without cardiotoxicity. Results: Over a follow-up period of almost 4 years, we found that 7% (32/458) of the cohort developed cardiotoxicity, with 37.5% (12/32) of these manifesting as clinical heart failure, whilst the rest were asymptomatic. The cardiotoxic cohort demonstrated a significantly higher mortality rate compared to the non-cardiotoxic group at 46.9 vs. 19.2% (p < 0.001), of whom 3 (9.4%) died from end-stage heart failure. We found that traditional predictors such as female sex, age at diagnosis, and cumulative doxorubicin equivalent dose were not predictors of cardiotoxicity. Conclusion: Our study reaffirms that freedom from symptoms does not ensure normal heart function and suggests that children with abnormal ventricular systolic function have higher mortality risk compared to those with normal systolic function. The findings contribute to improved understanding of the Asian burden to aid development of measures to prevent or reduce the risk of cardiotoxicity.

What Is the Cardiac Impact of Chemotherapy and Subsequent Radiotherapy in Lymphoma Patients?

Anthracyclines are widely used in anticancer protocols, but can induce cardiotoxicity by mechanisms that mainly involve oxidative damage and mitochondrial dysfunction. Radiotherapy (RT) can also impair cardiac function by promoting myocardial fibrosis, microvascular damage, and decreased density of myocardial capillaries. Hence, we aim at investigating prospectively whether RT impacts heart function in lymphoma patients who had been already treated with anthracyclines. Twenty-nine consecutive patients with Hodgkin or non-Hodgkin lymphomas underwent echocardiography at baseline (before antineoplastic treatments), and then every 2 months, until 6 months after treatment completion. Echo evaluation included standard two-dimensional and speckle tracking. Twenty-two patients treated with anthracycline-based regimens were eligible. Out of the 22 patients, 8 received chemotherapy (CT) only (subgroup 1), while 14 underwent RT after CT [subgroup 2 (S2)]. At the end of CT, ejection fraction was significantly reduced in the whole population. At 6 months after completion of therapies, E/E' increased and global longitudinal strain was compromised in S2, suggesting additional damage induced by RT after CT. On the basis of the data from our small prospective study, we can hypothesize that in lymphoma patients, anthracyclines can worsen cardiac function, and RT may have an additional unfavorable myocardial impact.

A Retrospective Evaluation of Risk of Peripartum Cardiac Dysfunction in Survivors of Childhood, Adolescent and Young Adult Malignancies

Long-term survivors of childhood, adolescent and young adult (AYA) malignancies with past exposure to potentially cardiotoxic treatments are at risk of peripartum cardiac dysfunction. Incidence and risk factors for peripartum cardiac dysfunction and maternal cardiac outcomes in this population were investigated. Eligible long-term survivors were aged <30 years at cancer diagnosis, with ≥1 pregnancy occurring ≥5 years after diagnosis. “Peripartum” cardiac events were defined as occurring within pregnancy or ≤5months after delivery. Cardiac events were classified “symptomatic” or “subclinical”. “Peripartum cardiomyopathy” (PPCM) was defined as symptomatic dysfunction without prior cardiac dysfunction. Of 64 eligible women, 5 (7.8%) had peripartum cardiac events: 3 symptomatic, 2 subclinical. Of 110 live births, 2 (1.8%, 95% CI 0.2–6.4) were defined as PPCM: Significantly greater than the published general population incidence of 1:3000 (p < 0.001), representing a 55-fold (95% CI 6.6–192.0) increased risk. Risk factor analyses were hypothesis-generating, revealing younger age at cancer diagnosis and higher anthracycline dose. Postpartum, cardiac function of 4 women (80%) failed to return to baseline. In conclusion, peripartum cardiac dysfunction is an uncommon but potentially serious complication in long-term survivors of paediatric and AYA malignancies previously treated with cardiotoxic therapies. Peripartum cardiac assessment is strongly recommended for at-risk patients.

Home-Based Exercise Training Improves Left Ventricle Diastolic Function in Survivors of Childhood ALL: A Tissue Doppler and Velocity Vector Imaging Study

BACKGROUND

Advanced echocardiographic methods may reveal signs of late anthracycline cardiac toxicity (ACT) even in asymptomatic patients. We studied echocardiographic tissue Doppler imaging (TDI) and velocity vector imaging (VVI) in long-term survivors of childhood acute lymphoblastic leukemia (ALL) before and after an exercise intervention.

METHODS

Twenty-one asymptomatic, anthracycline-treated, long-term childhood ALL survivors with matched controls were studied at baseline. Seventeen of the survivors participated in a 3-month home-based exercise program. Echocardiography with TDI and VVI was performed.

RESULTS

At baseline, ejection fraction (60.7 ± 4.7% vs. 62.3 ± 3.7%, P = 0.22) and fractional shortening (32.6 ± 3.1% vs. 34.0 ± 2.8%, P = 0.13) were similar in survivors and controls. Lateral early diastolic mitral annulus velocity E' (32.81 ± 5.71 cm/sec vs. 38.03 ± 6.21 cm/sec, P = 0.01), E'/A' (1.60 ± 0.48 vs. 2.07 ± 0.63, P = 0.01), and E/E' (2.78 ± 0.35 vs. 2.42 ± 0.62, P = 0.04) were impaired compared to controls. Peak circumferential strain and strain rate were attenuated at apex (-24.50 ± 3.46% vs. -28.06 ± 4.39%, P = 0.01 and -1.47 ± 0.22 sec(-1) vs. -1.68 ± 0.33 sec(-1) , P = 0.02) compared to controls. After the intervention, early diastolic mitral inflow velocity E (87.76 ± 12.54 cm/s vs. 95.28 ± 10.48 cm/s, P = 0.04) and E' increased (31.78 ± 5.50 cm/s vs. 34.96 ± 5.41 cm/s, P < 0.01). Peak circumferential systolic and diastolic strain rates at mid-level (-1.22 ± 0.21 sec(-1) vs. -1.35 ± 0.24 sec(-1) , P = 0.04 and 1.25 ± 0.25 sec(-1) vs. 1.48 ± 0.35 sec(-1) , P < 0.01) improved after the exercise program.

CONCLUSIONS

A simple home-based exercise program improved cardiac function in asymptomatic childhood ALL survivors. Adding TDI in routine echocardiographic examination may improve the recognition of early signs of ACT, and VVI may bring additional information. The improvements in cardiac function after the exercise program emphasize the importance of physical activity in this population.

Comparison of epirubicin and doxorubicin cardiotoxicity induced by low doses: evolution of the diastolic and systolic parameters studied by radionuclide angiography

BACKGROUND

Previous studies have demonstrated that epirubicin (EPI) has a lower propensity to produce cardiotoxic effects than doxorubicin (DXR) at high doses.

HYPOTHESIS

The aim of the study was to compare the cardiotoxicity induced by low doses of EPI and DXR in patients before and 1 month after the end of chemotherapy.

METHOD

In a prospective study, 99 patients with a mean age of 51 +/- 12 years and without cardiac disease were studied before and 1 month after the end of chemotherapy. Group 1 included 38 patients receiving 246 +/- 96 mg/m2 of DXR and Group 2 included 61 patients receiving EPI with and equivalent dose of 219 +/- 92 mg/m2 of DXR. Ejection fraction (EF) of the left ventricle (LV), peak ejection rate (PER), and peak filling rate (PFR) [expressed in end-diastolic volume/s (EDV/s)] were evaluated by gated radionuclide angiography; PFR/PER were also calculated.

RESULTS

Moderate and similar alterations of left ventricular ejection fraction were shown for low doses of anthracyclines. The EF of the LV decreased from 57 +/- 6% to 54 +/- 6% for DXR group (Group 1) (p = 0.005), and from 58 +/- 5% to 55 +/- 5% for the EPI group (Group 2)(p = 0.001). The PER of the left ventricle fell from 3.08 +/- 0.46 EDV/s to 2.79 +/- 0.49 in Group 1 (p = 0.004) and from 2.98 +/- 0.50 to 2.73 +/- 0.34 EDV/s in Group 2 (p = 0.001). In contrast, no significant alteration of PFR appeared in Group 2 (from 2.72 +/- 0.51 to 2.62 +/- 0.41 EDV/s) for the equivalent dose of anthracycline, while PFR of the LV dropped from 2.82 +/- 0.76 (EDV/s) to 2.41 +/- 0.55 after doxorubicin (p = 0.004). No difference was found between 1 and 12 months after the end of the treatment in 25 patients in Group 1 and 28 patients in Group 2. These results confirm the advantage of EPI over DXR in terms of cardiotoxicity and help explain the relationship of cellular damage mechanisms with the functional parameters of nuclear investigation.

CONCLUSION

A possible explanation for specific alteration after DXR could be the increased production of semiquinone free radicals, which are known to induce membrane damage and, consequently, myocardial edema and diastolic alteration.

Prevention by dexrazoxane of down-regulation of ryanodine receptor gene expression in anthracycline cardiomyopathy in the rat

Anthracyclines can cause cumulative dose-related cardiotoxicity characterized by changes in Ca(2+) metabolism, including dysfunction of the sacroplasmic reticulum (SR) and decreased expression of Ca(2+)-handling proteins, such as the ryanodine receptor (RyR2). In this study, we examined the effect of dexrazoxane (ICRF-187), an iron chelator which prevents anthracycline cardiotoxicity, on RyR2 gene expression in rats treated chronically with daunorubicin. Daunorubicin (2.5 mg kg(-1) i.v. weekly for 6 weeks) produced cardiotoxicity as demonstrated by histopathologic changes. The ryanodine receptor/glyceraldehyde phosphate dehydrogenase (GAPDH) mRNA ratio was decreased by 38+/-3% (P<0.02) compared to values in control rats. Dexrazoxane pre-treatment (50 mg kg(-1); 1 h prior to each daunorubicin injection) prevented the decrease in RyR2/GAPDH mRNA ratio and histopathologic lesions in daunorubicin-treated rats. This is the first report that a protective agent such as dexrazoxane can ameliorate the decreased expression of a specific gene involved in anthracycline-induced cardiotoxicity.