Cardiotoxicity of CPX-351 in children and adolescents with relapsed AML: a Children's Oncology Group report.

Introduction: Anthracyclines are effective in treating acute myeloid leukemia (AML) but limited by cardiotoxicity. CPX-351, a liposomal daunorubicin and cytarabine, may provide therapeutic benefit with less cardiotoxicity. Acute changes in left ventricular systolic function and cardiac biomarkers were evaluated after a cycle of CPX-351 in children with relapsed AML treated on the phase 1/2 Children's Oncology Group study, AAML1421. Methods: Subjects received 135 units/m2/dose of CPX-351 on days 1, 3, and 5 as cycle 1. Echocardiograms were performed and centrally quantitated at baseline and at the end of cycle 1 (day 29 +/- 1 week). High sensitivity troponin (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured at baseline and serially through the end of cycle 1 (days 5, 8, 15, 22 and 29). Differences between baseline and post-CPX-351 echo/biomarker measures were analyzed using Wilcoxon signed rank tests. Linear regression was used to model post-CPX-351 left ventricular ejection fraction (LVEF) with cTnT/NT-proBNP at each time point, controlling for baseline LVEF. Cancer therapy related cardiac dysfunction (CTRCD) was defined as a decline in LVEF of ≥10%-<50%. Results: Twenty-five of 38 heavily anthracycline pre-treated (median 348 mg/m2 daunorubicin equivalents) subjects enrolled on AAML1421 were included in the cardiac analyses. At baseline, centrally quantitated LVEF was <50% in 8 of 25 subjects (32%) with a median LVEF of 53.8% [48.0, 56.9]. Following CPX-351, LVEF declined significantly (ΔLVEF -3.3% [-7.8, 0]) and 6 of 25 subjects (24%) experienced CTRCD. Amongst all subjects, hs-cTnT was modestly increased at end of cycle 1 compared to baseline [baseline hs-cTnT 7.2 (3, 10.6); ΔcTnT 1.80 (0, 6.1), p = 0.03]. NT-proBNP remained stably elevated without significant change. No significant associations were seen between NT-proBNP or cTnT levels and post-CPX-351 LVEF. Discussion: In this single arm study of anthracycline pre-treated children exposed to CPX-351, baseline abnormalities in cardiovascular function were prevalent. Following CPX-351, LVEF decreased, cTnT increased, and NT-proBNP did not change. Longer follow-up is needed to determine whether these changes result in clinically meaningful long-term decrements in cardiac function. An ongoing randomized trial of CPX-351 compared to standard anthracyclines in anthracycline naïve patients will provide further insight into the cardiac effects of CPX-351 (ClinicalTrials.gov; NCT04293562).

Rationale and design of the Children's Oncology Group study AAML1831 integrated cardiac substudies in pediatric acute myeloid leukemia therapy.

Background: Pediatric acute myeloid leukemia (AML) therapy is associated with substantial short- and long-term treatment-related cardiotoxicity mainly due to high-dose anthracycline exposure. Early left ventricular systolic dysfunction (LVSD) compromises anthracycline delivery and is associated with inferior event-free and overall survival in de novo pediatric AML. Thus, effective cardioprotective strategies and cardiotoxicity risk predictors are critical to optimize cancer therapy delivery and enable early interventions to prevent progressive LVSD. While dexrazoxane-based cardioprotection reduces short-term cardiotoxicity without compromising cancer survival, liposomal anthracycline formulations have the potential to mitigate cardiotoxicity while improving antitumor efficacy. This overview summarizes the rationale and methodology of cardiac substudies within AAML1831, a randomized Children's Oncology Group Phase 3 study of CPX-351, a liposomal formulation of daunorubicin and cytarabine, in comparison with standard daunorubicin/cytarabine with dexrazoxane in the treatment of de novo pediatric AML. Methods/design: Children (age <22 years) with newly diagnosed AML were enrolled and randomized to CPX-351-containing induction 1 and 2 (Arm A) or standard daunorubicin and dexrazoxane-containing induction (Arm B). Embedded cardiac correlative studies aim to compare the efficacy of this liposomal anthracycline formulation to dexrazoxane for primary prevention of cardiotoxicity by detailed core lab analysis of standardized echocardiograms and serial cardiac biomarkers throughout AML therapy and in follow-up. In addition, AAML1831 will assess the ability of early changes in sensitive echo indices (e.g., global longitudinal strain) and cardiac biomarkers (e.g., troponin and natriuretic peptides) to predict subsequent LVSD. Finally, AAML1831 establishes expert consensus-based strategies in cardiac monitoring and anthracycline dose modification to balance the potentially competing priorities of cardiotoxicity reduction with optimal leukemia therapy. Discussion: This study will inform diagnostic, prognostic, preventative, and treatment strategies regarding cardiotoxicity during pediatric AML therapy. Together, these measures have the potential to improve leukemia-free and overall survival and long-term cardiovascular health in children with AML. Clinical trial registration: https://clinicaltrials.gov/, identifier NCT04293562.

Feasibility of a Health Coach Intervention to Reduce Sitting Time and Improve Physical Functioning Among Breast Cancer Survivors: Pilot Intervention Study.

BACKGROUND: Sedentary behavior among breast cancer survivors is associated with increased risk of poor physical function and worse quality of life. While moderate to vigorous physical activity can improve outcomes for cancer survivors, many are unable to engage in that intensity of physical activity. Decreasing sitting time may be a more feasible behavioral target to potentially mitigate the impact of cancer and its treatments. OBJECTIVE: The purpose of this study was to investigate the feasibility and preliminary impact of an intervention to reduce sitting time on changes to physical function and quality of life in breast cancer survivors, from baseline to a 3-month follow-up. METHODS: Female breast cancer survivors with self-reported difficulties with physical function received one-on-one, in-person personalized health coaching sessions aimed at reducing sitting time. At baseline and follow-up, participants wore the activPAL (thigh-worn accelerometer; PAL Technologies) for 3 months and completed physical function tests (4-Meter Walk Test, Timed Up and Go, and 30-Second Chair Stand) and Patient-Reported Outcomes Measurement Information System (PROMIS) self-reported outcomes. Changes in physical function and sedentary behavior outcomes were assessed by linear mixed models. RESULTS: On average, participants (n=20) were aged 64.5 (SD 9.4) years; had a BMI of 30.4 (SD 4.5) kg/m2; and identified as Black or African American (n=3, 15%), Hispanic or Latina (n=4, 20%), and non-Hispanic White (n=14, 55%). Average time since diagnosis was 5.8 (SD 2.2) years with participants receiving chemotherapy (n=8, 40%), radiotherapy (n=18, 90%), or endocrine therapy (n=17, 85%). The intervention led to significant reductions in sitting time: activPAL average daily sitting time decreased from 645.7 (SD 72.4) to 532.7 (SD 142.1; ß=-112.9; P=.001) minutes and average daily long sitting bouts (bout length ≥20 min) decreased from 468.3 (SD 94.9) to 366.9 (SD 150.4; ß=-101.4; P=.002) minutes. All physical function tests had significant improvements: on average, 4-Meter Walk Test performance decreased from 4.23 (SD 0.95) to 3.61 (SD 2.53; ß=-.63; P=.002) seconds, Timed Up and Go performance decreased from 10.30 (SD 3.32) to 8.84 (SD 1.58; ß=-1.46; P=.003) seconds, and 30-Second Chair Stand performance increased from 9.75 (SD 2.81) to 13.20 completions (SD 2.53; ß=3.45; P<.001). PROMIS self-reported physical function score improved from 44.59 (SD 4.40) to 47.12 (SD 5.68; ß=2.53; P=.05) and average fatigue decreased from 52.51 (SD 10.38) to 47.73 (SD 8.43; ß=-4.78; P=.02). CONCLUSIONS: This 3-month pilot study suggests that decreasing time spent sitting may be helpful for breast cancer survivors experiencing difficulties with physical function and fatigue. Reducing sitting time is a novel and potentially more feasible approach to improving health and quality of life in cancer survivors.

Cardiovascular profile of contemporary treatments of renal cell carcinoma: A single-center prospective study.

BACKGROUND: Tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs) have revolutionized the treatment of metastatic renal cell carcinoma (mRCC). Emerging data suggest that these agents can result in clinically significant cardiotoxicity, compromising the care. METHODS: We conducted a prospective longitudinal study to evaluate the incidence of de novo cardiac dysfunction as assessed by echocardiography and blood biomarkers in mRCC patients receiving TKI with or without ICI followed at baseline, 3-month and 6-month. We recruited consecutive newly diagnosed mRCC patients treated at our institution between 2015 and 2018 as well as patients with localized RCC not treated with systemic therapies and healthy control (HC) subjects for comparison. RESULTS: Twenty-eight patients were enrolled in the mRCC group (a mean age of 65.2 ± 7.5 years), 29 patients in the localized RCC group (63.6 ± 8.9 years), and 20 volunteers in the HC group (52.9 ± 9.6 years). At baseline, patients from all three groups had normal cardiac function as measured by left ventricular ejection fraction (LVEF), although patients with mRCC or localized RCC had significantly lower mean LVEF compared to HC (61.9%, 62.4%, and 68.1% respectively). Otherwise, there were no statistically significant changes in echocardiographic parameters or incidence of clinical heart failure from baseline to 6-months in patients with mRCC. Cardiac blood biomarkers including troponin I, brain natriuretic peptide, and galectin-3 remained stable over time. CONCLUSION: Our findings suggest that contemporary treatment strategies of mRCC at this single institution are well tolerated without clinically meaningful overt declines in cardiac function over time. Further studies are warranted to include a larger number of patients to better assess the overall cardiovascular safety associated with contemporary treatments of mRCC.

Cardiovascular toxicities with pediatric tyrosine kinase inhibitor therapy: An analysis of adverse events reported to the Food and Drug Administration.

We sought to examine cardiovascular toxicities associated with tyrosine kinase inhibitors in pediatrics. We examined 1624 pediatric adverse events with imatinib, dasatinib, sorafenib, pazopanib, crizotinib, and ruxolitinib reported to the Food and Drug Administration between January 1, 2015, and August 14, 2020. There were 102 cardiovascular event reports. Hypertension was the most commonly reported cardiovascular event and was most frequently associated with sorafenib and pazopanib. The presence of infection increased the reporting odds of cardiovascular events overall and specifically cardiac arrest, heart failure, and hypertension. These data provide early insight into cardiovascular toxicities with tyrosine kinase inhibitor use in pediatrics.

Fitbit Use and Activity Levels From Intervention to 2 Years After: Secondary Analysis of a Randomized Controlled Trial.

BACKGROUND: There has been a rapid increase in the use of commercially available activity trackers, such as Fitbit, in physical activity intervention research. However, little is known about the long-term sustained use of trackers and behavior change after short-term interventions. OBJECTIVE: This study aims to use minute-level data collected from a Fitbit tracker for up to 2 years after the end of a randomized controlled trial to examine patterns of Fitbit use and activity over time. METHODS: Participants in this secondary data analysis were 75 female breast cancer survivors who had been enrolled in a 12-week physical activity randomized controlled trial. Participants randomized to the exercise intervention (full intervention arm) received a Fitbit One, which was worn daily throughout the 12-week intervention, and then were followed for 2 years after the intervention. Participants randomized to the waitlist arm, after completing the randomized controlled trial, received a Fitbit One and a minimal version of the exercise intervention (light intervention arm), and then were followed for 2 years after the intervention. Average and daily adherence and MVPA were compared between the 2 groups in the interventional and postinterventional periods using both linear and generalized additive mixed effects models. RESULTS: Adherence to wearing the Fitbit during the 12-week intervention period was significantly higher in the full intervention arm than in the light intervention arm (85% vs 60%; P<.001). Average adherence was significantly lower for both study arms during the follow-up period than in the intervention period; however, there were statistically different patterns of adherence during the follow-up period, with the light intervention arm having steeper declines than the full intervention arm over time (P<.001). Similar to the adherence results, mean minutes of Fitbit-measured MVPA was higher for the full intervention arm than for the light intervention arm during the 12-week intervention period (mean MVPA 27.89 minutes/day, SD 16.38 minutes/day vs 18.35 minutes/day, SD 12.64 minutes/day; P<.001). During the follow-up period, average MVPA was significantly lower than the 12-week intervention period for both the full intervention arm (21.74 minutes/day, SD 24.65 minutes/day; P=.002) and the light intervention arm (15.03 minutes/day, SD 13.27 minutes/day; P=.004). Although the mean MVPA in each arm was similar across the follow-up period (P=.33), the pattern of daily MVPA was significantly different between the 2 groups (P<.001). CONCLUSIONS: While adherence to wearing activity trackers and maintaining physical activities declined after completion of a 12-week exercise intervention, a more active interventional strategy resulted in greater wear time and activity levels during the intervention and more stable patterns of adherence and activity in the long term. An improved understanding of long-term maintenance patterns may inform improved exercise interventions that result in sustained increases in physical activity. TRIAL REGISTRATION: ClinicalTrials.gov NCT02332876; https://clinicaltrials.gov/ct2/show/NCT02332876.

Minimizing cardiac toxicity in children with acute myeloid leukemia.

Anthracycline chemotherapy remains an integral component of modern pediatric acute myeloid leukemia (AML) regimens and is often delivered at high doses to maximize cancer survival. Unfortunately, high-dose anthracyclines are associated with a significant risk of cardiotoxicity, which may result in early and/or long-term left ventricular systolic dysfunction and heart failure. Moreover, the development of cardiotoxicity during pediatric AML therapy is associated with lower event-free and overall survival, which may be partially attributable to incomplete anthracycline delivery. A combined strategy of primary cardioprotection and close cardiac monitoring can maximize chemotherapy delivery while reducing the toxicity of intensive AML therapy. Primary cardioprotection using dexrazoxane reduces short-term cardiotoxicity without compromising cancer survival. Liposomal anthracycline formulations, which are under active investigation, have the potential to mitigate cardiotoxicity while also improving antitumor efficacy. Primary cardioprotective strategies may reduce but not eliminate the risk of cardiotoxicity; therefore, close cardiac monitoring is also needed. Standard cardiac monitoring consists of serial echocardiographic assessments for left ventricular ejection fraction decline. Global longitudinal strain has prognostic utility in cancer therapy-related cardiotoxicity and may be used as an adjunct assessment. Additional cardioprotective measures should be considered in response to significant cardiotoxicity; these include cardiac remodeling medications to support cardiac recovery and anthracycline dose interruption and/or regimen modifications. However, the withholding of anthracyclines should be limited to avoid compromising cancer survival. A careful approach to cardioprotection during AML therapy is critical to maximize the efficacy of leukemia treatment while minimizing the short- and long-term risks of cardiotoxicity.

Molecular mechanisms of anthracycline cardiovascular toxicity.

Anthracyclines are effective chemotherapeutic agents, commonly used in the treatment of a variety of hematologic malignancies and solid tumors. However, their use is associated with a significant risk of cardiovascular toxicities and may result in cardiomyopathy and heart failure. Cardiomyocyte toxicity occurs via multiple molecular mechanisms, including topoisomerase II-mediated DNA double-strand breaks and reactive oxygen species (ROS) formation via effects on the mitochondrial electron transport chain, NADPH oxidases (NOXs), and nitric oxide synthases (NOSs). Excess ROS may cause mitochondrial dysfunction, endoplasmic reticulum stress, calcium release, and DNA damage, which may result in cardiomyocyte dysfunction or cell death. These pathophysiologic mechanisms cause tissue-level manifestations, including characteristic histopathologic changes (myocyte vacuolization, myofibrillar loss, and cell death), atrophy and fibrosis, and organ-level manifestations including cardiac contractile dysfunction and vascular dysfunction. In addition, these mechanisms are relevant to current and emerging strategies to diagnose, prevent, and treat anthracycline-induced cardiomyopathy. This review details the established and emerging data regarding the molecular mechanisms of anthracycline-induced cardiovascular toxicity.

Early Changes in Physical Activity and Quality of Life With Thoracic Radiation Therapy in Breast Cancer, Lung Cancer, and Lymphoma.

PURPOSE: The effects of thoracic radiation therapy (RT) on physical functioning and quality of life (QoL) are incompletely defined. We determined the associations between thoracic RT dose volume metrics, physical activity, and QoL in patients with cancer. METHODS AND MATERIALS: Participants with breast cancer, lung cancer, or mediastinal lymphoma treated with radiation with or without chemotherapy were enrolled in a prospective, longitudinal cohort study. Data were collected pre-RT, immediately post-RT, and 5 to 9 months post-RT. At each timepoint, self-reported physical activity was assessed via the Godin-Shephard Leisure-Time Physical Activity Questionnaire, and QoL metrics were assessed via Functional Assessment of Chronic Illness Therapy Fatigue and Dyspnea Scales. Multivariable adjusted linear regression models were stratified by breast cancer alone and lung cancer and lymphoma combined. RESULTS: One hundred thirty participants were included in the study. In breast cancer (n = 80), each 1-Gy increase in mean heart dose was associated with worse Functional Assessment of Chronic Illness Therapy Fatigue scores (-1.0; 95% confidence interval [CI], -1.9 to -0.2; P = .021); similar associations were observed between V5 and fatigue (-2.5; 95% CI, -4.4 to -0.6; P = .010 for each 10% increase in V5). In lung cancer and lymphoma (n = 50), each 10% increase in V5 was associated with decreased physical activity (Godin-Shephard Leisure-Time Physical Activity Questionnaire score -2.3; 95% CI, -4.3 to -0.4; P = .017). Although the associations between baseline levels of physical activity and fatigue and dyspnea were of borderline significance in breast cancer alone (P < .10), increased physical activity over time was associated with improvements in fatigue and dyspnea across all cancer types (P < .05 for all). CONCLUSIONS: Higher cardiac RT dose was associated with worse fatigue and physical activity across breast cancer, lung cancer, and mediastinal lymphoma. Longitudinal increases in physical activity were associated with concurrent improvements in QoL measures. Strategies to increase physical activity and decrease cardiac RT dose may improve physical functioning and QoL for patients with cancer.

Left ventricular segmental strain and the prediction of cancer therapy-related cardiac dysfunction.

AIMS: We aimed to determine the early changes and predictive value of left ventricular (LV) segmental strain measures in women with breast cancer receiving doxorubicin. METHODS AND RESULTS: In a cohort of 237 women with breast cancer receiving doxorubicin with or without trastuzumab, 1151 echocardiograms were prospectively acquired over a median (Q1-Q3) of 7 (2-24) months. LV ejection fraction (LVEF) and 36 segmental strain measures were core lab quantified. A supervised machine learning (ML) model was then developed using random forest regression to identify segmental strain measures predictive of nadir LVEF post-doxorubicin completion. Cancer therapy-related cardiac dysfunction (CTRCD) was defined as a ≥10% absolute LVEF decline pre-treatment to a value <50%. Median (Q1-Q3) baseline age was 48 (41-57) years. Thirty-five women developed CTRCD, and eight of these developed symptomatic heart failure. From pre-treatment to doxorubicin completion, longitudinal strain worsened across the basal and mid-LV segments but not in the apical segments; circumferential strain worsened primarily in the septum; radial strain worsened uniformly and transverse strain remained unchanged across all LV segments. In the ML model, anterolateral and inferoseptal circumferential strain were the most predictive features; longitudinal and transverse strain in the basal inferoseptal, anterior, basal anterolateral, and apical lateral segments were also top predictive features. The addition of predictive segmental strain measures to a model including age, cancer therapy regimen, hypertension, and LVEF increased the area under the curve (AUC) from 0.70 (95% confidence interval (CI) 0.60-0.80) to 0.87 (95% CI 0.81-0.92), ΔAUC = 0.18 (95% CI 0.08-0.27) for the prediction of CTRCD. CONCLUSION: Our findings suggest that segmental strain measures can enhance cardiotoxicity risk prediction in women with breast cancer receiving doxorubicin.

Atlas-based measures of left ventricular shape may improve characterization of adverse remodeling in anthracycline-exposed childhood cancer survivors: a cross-sectional imaging study.

BACKGROUND: Adverse cardiac remodeling is an important precursor to anthracycline-related cardiac dysfunction, however conventional remodeling indices are limited. We sought to examine the utility of statistical atlas-derived measures of ventricular shape to improve the identification of adverse anthracycline-related remodeling in childhood cancer survivors. METHODS: We analyzed cardiac magnetic resonance imaging from a cross-sectional cohort of 20 childhood cancer survivors who were treated with low (< 250 mg/m2 [N = 10]) or high (≥250 mg/m2 [N = 10]) dose anthracyclines, matched 1:1 by sex and age between dose groups. We reconstructed 3D computational models of left ventricular end-diastolic shape for each subject and assessed the ability of conventional remodeling indices (volume, mass, and mass to volume ratio) vs. shape modes derived from a statistical shape atlas of an asymptomatic reference population to stratify anthracycline-related remodeling. We compared conventional parameters and five atlas-based shape modes: 1) between survivors and the reference population (N = 1991) using multivariable linear regression, and 2) within survivors by anthracycline dose (low versus high) using two-sided T-tests, multivariable logistic regression, and receiver operating characteristic curves. RESULTS: Compared with the reference population, survivors had differences in conventional measures (lower volume and mass) and shape modes (corresponding to lower overall size and lower sphericity; all p < 0.001). Among survivors, differences in a shape mode corresponding to increased basal cavity size and altered mitral annular orientation in the high-dose group were observed (p = 0.039). Collectively, atlas-based shape modes in conjunction with conventional measures discriminated survivors who received low vs. high anthracycline dosage (area under the curve [AUC] 0.930, 95% confidence interval 0.816, 1.00) significantly better than conventional measures alone (AUC 0.710, 95% confidence interval 0.473, 0.947; AUC comparison p = 0.0498). CONCLUSIONS: Compared with a reference population, heart size is smaller in anthracycline-exposed childhood cancer survivors. Atlas-based measures of left ventricular shape may improve the detection of anthracycline dose-related remodeling differences.

Comprehensive Assessment of Changes in Left Ventricular Diastolic Function With Contemporary Breast Cancer Therapy.

OBJECTIVES: This study determined the effects of doxorubicin and/or trastuzumab on diastolic function and the relationship between diastolic function and systolic dysfunction. BACKGROUND: Doxorubicin and trastuzumab can result in left ventricular ejection fraction (LVEF) declines. However, the effects of these therapies on diastolic function remain incompletely defined. METHODS: In a rigorously phenotyped, longitudinal cohort study of 362 breast cancer participants treated with doxorubicin, doxorubicin followed by trastuzumab, or trastuzumab alone, changes in diastolic function were evaluated using linear models estimated via generalized estimating equations. Associations between baseline and changes in diastolic function with LVEF and longitudinal strain were also determined using generalized estimating equations. The Kaplan-Meier estimator derived the proportion of participants who experienced incident diastolic dysfunction. Cox proportional hazards models estimated the associations between participant characteristics and diastolic dysfunction risk, and between diastolic function and cancer therapy-related cardiac dysfunction risk, defined by an LVEF decline of ≥10% to <50%. RESULTS: Over a median of 2.1 years (interquartile range [IQR]: 1.3 to 4.2 years), participants treated with doxorubicin or doxorubicin followed by trastuzumab demonstrated a persistent worsening in diastolic function, with reductions in the E/A ratio, lateral and septal e' velocities, and increases in E/e' (p < 0.01). These changes were not observed with trastuzumab alone. Incident abnormal diastolic function grade occurred in 60% at 1 year, 70% by 2 years, and 80% by 3 years. Abnormal diastolic function grade was associated with a subsequent decrease in LVEF (-2.1%; 95% confidence intervals [CI]: -3.1 to -1.2; p < 0.001) and worsening in longitudinal strain (0.6%; 95% CI: 0.1 to 1.1; p = 0.013) over time. Changes in E/e' ratio were modestly associated with worsening longitudinal strain (0.1%; 95% CI: 0.0 to 0.2; p = 0.022). CONCLUSIONS: A modest, persistent worsening of diastolic function is observed with contemporary breast cancer therapy. Abnormal and worsening diastolic dysfunction is associated with a small risk of subsequent systolic dysfunction. (Cardiotoxicity of Cancer Therapy [CCT]; NCT01173341).

Dexrazoxane preferentially mitigates doxorubicin cardiotoxicity in female children with sarcoma.

Objective: We sought to determine how sex and dexrazoxane therapy influence cardiac remodelling in children with sarcoma receiving high-dose doxorubicin. Methods: In a retrospective cohort of 85 children with sarcoma receiving high-dose doxorubicin, echocardiography measures prior to, early after (within 6 months of doxorubicin completion) and 1 - 2 years after doxorubicin completion were quantified. At each follow-up visit, multivariable, propensity-adjusted linear regression models evaluated dexrazoxane's effects on changes in left ventricular (LV) shortening fraction (SF), structure, strain and wall stress for subgroups divided by sex. Likelihood ratio tests assessed the interaction between sex and dexrazoxane in determining these changes. Results: Early after doxorubicin completion, males not treated with dexrazoxane (n = 15) developed increased cavity size and diminished circumferential strain; females (n = 8) developed diminished SF and strain indices, and increased cavity size and wall stress. With dexrazoxane, males (n = 33) demonstrated less deterioration in circumferential strain by 3.4% (95% CI 0.01 to 6.8), and females (n = 29) demonstrated less reduction in SF by 5.7% (95% CI 2.1 to 9.3), and had mitigation of increases in cavity size and wall stress. In interaction analyses, females had greater protection with dexrazoxane with regard to SF (p = 0.019) and cavity size in diastole (p = 0.002) and systole (p ≤ 0.001). These findings largely persisted 1 - 2 years after doxorubicin therapy. Conclusions: Early, sustained alterations in LV structure and function occur in children with sarcoma after high-dose doxorubicin, with adverse changes and protective effects of dexrazoxane more pronounced in females as compared with males. Dexrazoxane may have sex-specific cardioprotective effects.

Detailed phenotyping reveals distinct trajectories of cardiovascular function and symptoms with exposure to modern breast cancer therapy.

BACKGROUND: Breast cancer therapies are associated with a risk of cardiac dysfunction, most commonly defined by changes in left ventricular ejection fraction (LVEF). Recently, the authors identified 3 classes of LVEF change after exposure to anthracyclines and/or trastuzumab using latent class growth modeling. The objective of the current study was to characterize the clinical, biochemical, and functional profiles associated with LVEF trajectory class membership. METHODS: Transthoracic echocardiography and biomarker assessments were performed and questionnaires were administered at standardized intervals in a longitudinal cohort of 314 patients with breast cancer who were treated with anthracyclines and/or trastuzumab. Univariable and multivariable multinomial regression analyses evaluated associations between baseline variables and LVEF trajectory class membership. Generalized estimating equations were used to define mean changes in cardiovascular measures over time within each class. RESULTS: Among the 3 distinct subgroups of LVEF changes identified (stable [class 1]; modest, persistent decline [class 2]; and significant early decline followed by partial recovery [class 3]), higher baseline LVEF, radiotherapy, and sequential therapy with anthracyclines and/or trastuzumab were associated with class 2 or 3 membership. Sustained abnormalities in longitudinal strain and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were observed in patients in class 2, as were heart failure symptoms. Similar abnormalities were observed in patients in class 3, but there was a trend toward recovery, particularly for longitudinal strain. CONCLUSIONS: Patients with modest, persistent LVEF declines experienced sustained abnormalities in imaging and biochemical markers of cardiac function and heart failure symptoms. Further investigation is needed to characterize the long-term risk of heart failure, particularly in those with modest LVEF declines.

Abnormalities in 3-Dimensional Left Ventricular Mechanics With Anthracycline Chemotherapy Are Associated With Systolic and Diastolic Dysfunction.

OBJECTIVES: The objective of this study was to evaluate the changes in three-dimensional (3D) speckle-tracking echocardiography-derived measures of mechanics and their associations with systolic and diastolic dysfunction after anthracyclines. BACKGROUND: An improved understanding of the changes in 3D cardiac mechanics with anthracyclines may provide important mechanistic insight and identify new metrics to detect cardiac dysfunction. METHODS: A total of 142 women with breast cancer receiving doxorubicin (240 mg/m2) with or without trastuzumab underwent 3D speckle-tracking echocardiography at standardized intervals prior to, during, and annually after chemotherapy. Left ventricular ejection fraction (LVEF), global circumferential strain (GCS), global longitudinal strain (GLS), principal strain, twist, and torsion were quantified. Linear regression analyses defined the associations between clinical factors and 3D parameters. Linear regression models with cluster robust variance estimators determined the associations between 3D measures and 2-dimensional (2D) LVEF and Doppler-derived E/e' over time. RESULTS: There were significant abnormalities in 3D LVEF, GCS, GLS, and principal strain post-doxorubicin compared with control subjects (p < 0.001). The 3D parameters worsened post-anthracyclines, and only partially recovered to baseline over a median of 2.1 years (interquartile range: 1 to 4 years). Higher blood pressure and body mass index were associated with worse post-anthracycline 3D GCS and GLS, respectively. All 3D measures were associated with 2D LVEF at the same visit; only 3D LVEF, GCS, GLS, and principal strain were associated with 2D LVEF at subsequent visits (p < 0.05). In exploratory analyses, 3D LVEF and GCS were associated with subsequent systolic function independent of their corresponding 2D measures. The 3D LVEF, GCS, principal strain, and twist were significantly associated with concurrent, but not subsequent, E/e'. CONCLUSIONS: Anthracyclines result in early and persistent abnormalities in 3D mechanics. The 3D LVEF and strain measures are associated with concurrent and subsequent systolic dysfunction, and concurrent diastolic dysfunction. Future research is needed to define the mechanisms and clinical relevance of abnormal 3D mechanics.