Utility of 3-dimensional echocardiography, global longitudinal strain, and exercise stress echocardiography to detect cardiac dysfunction in breast cancer patients treated with doxorubicin-containing adjuvant therapy

Effects of Systemic Anticancer Treatment on Cardiorespiratory Fitness: A Systematic Review and Meta-Analysis

BACKGROUND

Poor cardiorespiratory fitness (CRF) is associated with a higher symptom burden and an increased prevalence of long-term treatment-related cardiovascular disease risk factors in cancer survivors. However, the magnitude of systemic therapy-related CRF impairment remains unclear.

OBJECTIVES

The aim of this study was to evaluate the effects of systemic anticancer treatment on CRF and identify physiological determinants underpinning CRF impairment.

METHODS

A systematic literature search was performed in PubMed, Embase, CINAHL, SPORTDiscus, and the Cochrane Library. The primary endpoint was the change in CRF, measured by peak oxygen consumption (Vo2peak), from before to after systemic treatment. Secondary endpoints included post-treatment differences in Vo2peak between cancer survivors and noncancer control subjects, along with physiological determinants of Vo2peak. Two meta-regressions were conducted to examine the association between CRF and cardiac output and arteriovenous oxygen difference.

RESULTS

A total of 44 studies were included, comprising 27 prospective trials (61%; n = 1,234 cancer survivors, median age 52.4 years) and 17 cross-sectional studies (39%; n = 1,372 cancer survivors, median age 54.0 years; n = 1,923 noncancer control subjects, median age 56.0 years). Systemic anticancer treatment was associated with a significant decrease in Vo2peak (weighted mean difference -2.13 mL·kg-1·min-1; 95% CI: -2.76 to -1.50 mL·kg-1·min-1). No significant differences were observed between patient subgroups (esophagogastric, breast, and colon or rectal cancers). At a median follow-up of 2 years (range: 6 weeks to 12 years) post-therapy, cancer survivors had a significantly lower Vo2peak (weighted mean difference -6.39 mL·kg-1·min-1; 95% CI: -7.60 to -5.18 mL·kg-1·min-1) compared with noncancer control subjects. Reduced arteriovenous oxygen difference was associated with lower Vo2peak (β = 2.55; 95% CI: 2.05-3.06; P < 0.001).

CONCLUSIONS

Systemic anticancer treatment leads to substantial and sustained impairments in CRF.

Cardiorespiratory fitness, cardiac morphology and function, and cardiovascular risk factors in long-term breast cancer survivors compared with non-cancer controls

BACKGROUND

Although anthracycline-related cardiotoxicity is widely studied, only a limited number of echocardiographic studies have assessed cardiac function in breast cancer survivors (BCSs) beyond ten years from anthracycline treatment, and the knowledge of long-term cardiorespiratory fitness (CRF) in this population is scarce. This study aimed to compare CRF assessed as peak oxygen uptake (V̇O2), cardiac morphology and function, and cardiovascular (CV) risk factors between long-term BCSs treated with anthracyclines and controls with no history of cancer.

METHODS

The CAUSE (Cardiovascular Survivors Exercise) trial included 140 BCSs recruited through the Cancer Registry of Norway, who were diagnosed with breast cancer stage II to III between 2008 and 2012 and had received treatment with epirubicin, and 69 similarly aged activity level-matched controls. All the participants underwent blood sampling, blood pressure measurements, echocardiography and cardiopulmonary exercise testing from October 2020 to August 2022.

RESULTS

BCSs were aged 59 ± 6 years and had received a cumulative dose of 357 (243 to 366) mg/m2 of epirubicin on average 11 ± 1 years before inclusion. There was no difference between BCSs and controls with respect to peak V̇O2 (27.6 ± 5.4 mL/kg/min vs. 27.1 ± 5.4 mL/kg/min, P = 0.25), 2D left ventricular ejection fraction (57 ± 3% vs. 57 ± 3%, P = 0.43), left ventricular global longitudinal strain (-20.5 ± 1.0% vs. -20.6 ± 1.0%, P = 0.46) or the proportion with N-terminal pro-brain natriuretic peptide ≥ 125 (22% vs. 20%, P = 0.93). The proportions with hypertension, dyslipidemia or diabetes did not differ between the groups.

CONCLUSION

We found that CRF, cardiac function, and CV risk profile in BCSs examined a decade after treatment with anthracyclines were similar to that in women with no history of cancer.

TRIAL REGISTRATION

clinicaltrials.gov (NCT04307407) https://clinicaltrials.gov/ct2/show/NCT04307407 .

Machine Learning-Driven Phenogrouping and Cardiorespiratory Fitness Response in Metastatic Breast Cancer

PURPOSE

The magnitude of cardiorespiratory fitness (CRF) impairment during anticancer treatment and CRF response to aerobic exercise training (AT) are highly variable. The aim of this ancillary analysis was to leverage machine learning approaches to identify patients at high risk of impaired CRF and poor CRF response to AT.

METHODS

We evaluated heterogeneity in CRF among 64 women with metastatic breast cancer randomly assigned to 12 weeks of highly structured AT (n = 33) or control (n = 31). Unsupervised hierarchical cluster analyses were used to identify representative variables from multidimensional prerandomization (baseline) data, and to categorize patients into mutually exclusive subgroups (ie, phenogroups). Logistic and linear regression evaluated the association between phenogroups and impaired CRF (ie, ≤16 mL O2·kg-1·min-1) and CRF response.

RESULTS

Baseline CRF ranged from 10.2 to 38.8 mL O2·kg-1·min-1; CRF response ranged from -15.7 to 4.1 mL O2·kg-1·min-1. Of the n = 120 candidate baseline variables, n = 32 representative variables were identified. Patients were categorized into two phenogroups. Compared with phenogroup 1 (n = 27), phenogroup 2 (n = 37) contained a higher number of patients with none or >three lines of previous anticancer therapy for metastatic disease and had lower resting left ventricular systolic and diastolic function, cardiac output reserve, hematocrit, lymphocyte count, patient-reported outcomes, and CRF (P < .05) at baseline. Among patients allocated to AT (phenogroup 1, n = 12; 44%; phenogroup 2, n = 21; 57%), CRF response (-1.94 ± 3.80 mL O2·kg-1·min-1 v 0.70 ± 2.22 mL O2·kg-1·min-1) was blunted in phenogroup 2 compared with phenogroup 1.

CONCLUSION

Phenotypic clustering identified two subgroups with unique baseline characteristics and CRF outcomes. The identification of CRF phenogroups could help improve cardiovascular risk stratification and guide investigation of targeted exercise interventions among patients with cancer.

The role of stress echocardiography in identifying cardiotoxicity: an in-depth exploration

Cancer treatment might cause heart failure and deteriorate the patients' quality of life. Despite the wide use of conventional echocardiography, it often fails to detect cardiotoxicity until advanced cardiac dysfunction at potentially irreversible stages. Advanced techniques, such as three-dimensional imaging and strain analysis in stress echocardiography, have shown promise in identifying cardiotoxicity at subclinical stages, even when traditional measures remain within normal ranges. These novel techniques have been shown to identify cardiac impairment in 30%-50% of the patients undergoing potentially cardiotoxic chemotherapy, which allows for early intervention and enhanced patient management. Although professional societies are advocating for the inclusion of these techniques into routine monitoring protocols, more research is needed to optimize and standardize their use across various centers and chemotherapeutic agents. This review explores the role of stress echocardiography in the early detection and monitoring of chemotherapy-induced cardiotoxicity. It delves into current knowledge and emerging research, aiming to provide a comprehensive understanding and to highlight areas worthy of further investigation.

Progress in the Use of Echocardiography in Patients with Tumors

Advances in cancer treatment have increased patient survival rates, shifting clinical focus towards minimizing treatment-related morbidity, including cardiovascular issues. Since echocardiography allows for a comprehensive non-invasive assessment at all cancer stages, it is well suited to monitor cardiovascular disease secondary to oncology treatment. This has earned it significant attention in the study of cardiac tumors and treatment-induced cardiac alterations. Ultrasound methods-ranging from transthoracic and transesophageal echocardiography to ultrasound diagnostic techniques including myocardial strain imaging, myocardial work indices, three-dimensional cardiac imaging-offer a holistic view of both the tumor and its treatment impact cardiac function. Stress echocardiography, myocardial contrast echocardiography, and myocardial acoustic angiography further augment this capability. Together, these echocardiographic techniques provide clinicians with early detection opportunities for cardiac damage, enabling timely interventions. As such, echocardiography continues to be instrumental in monitoring and managing the cardiovascular health of oncology patients, complementing efforts to optimize their overall treatment and survival outcomes.

Exposure to Doxorubicin Modulates the Cardiac Response to Isoproterenol in Male and Female Mice

Sex is a salient risk factor in the development of doxorubicin-induced cardiotoxicity. Sex differences in the heart's ability to respond to hypertrophic stimuli in doxorubicin-exposed animals have not been reported. We identified the sexual dimorphic effects of isoproterenol in mice pre-exposed to doxorubicin. Male and female intact or gonadectomized C57BL/6N mice underwent five weekly intraperitoneal injections of 4 mg/kg doxorubicin followed by a five-week recovery period. Fourteen days of subcutaneous isoproterenol injections (10 mg/kg/day) were administered after the recovery period. Echocardiography was used to assess heart function one and five weeks after the last doxorubicin injection and on the fourteenth day of isoproterenol treatment. Thereafter, mice were euthanized, and the hearts were weighed and processed for histopathology and gene expression analysis. Doxorubicin did not produce overt cardiac dysfunction in male or female mice before starting isoproterenol treatment. The chronotropic response to a single isoproterenol injection was blunted by doxorubicin, but the inotropic response was maintained in both males and females. Pre-exposure to doxorubicin caused cardiac atrophy in both control and isoproterenol-treated male mice but not in female mice. Counterintuitively, pre-exposure to doxorubicin abrogated isoproterenol-induced cardiac fibrosis. However, there were no sex differences in the expression of markers of pathological hypertrophy, fibrosis, or inflammation. Gonadectomy did not reverse the sexually dimorphic effects of doxorubicin. Additionally, pre-exposure to doxorubicin abrogated the hypertrophic response to isoproterenol in castrated male mice but not in ovariectomized female mice. Therefore, pre-exposure to doxorubicin caused male-specific cardiac atrophy that persisted after isoproterenol treatment, which could not be prevented by gonadectomy.

Protocol for pyrotinib cardiac safety in patients with HER2-positive early or locally advanced breast cancer-The EARLY-MYO-BC study

Background and aim

Cardiotoxicity has become the most common cause of non-cancer death among breast cancer patients. Pyrotinib, a tyrosine kinase inhibitor targeting HER2, has been successfully used to treat breast cancer patients but has also resulted in less well-understood cardiotoxicity. This prospective, controlled, open-label, observational trial was designed to characterize pyrotinib's cardiac impacts in the neoadjuvant setting for patients with HER2-positive early or locally advanced breast cancer.

Patients and methods

The EARLY-MYO-BC study will prospectively enroll HER2-positive breast cancer patients who are scheduled to receive four cycles of neoadjuvant therapy with pyrotinib or pertuzumab added to trastuzumab before radical breast cancer surgery. Patients will undergo comprehensive cardiac assessment before and after neoadjuvant therapy, including laboratory measures, electrocardiography, transthoracic echocardiography, cardiopulmonary exercise testing (CPET), and cardiac magnetic resonance (CMR). To test the non-inferiority of pyrotinib plus trastuzumab therapy to pertuzumab plus trastuzumab therapy in terms of cardiac safety, the primary endpoint will be assessed by the relative change in global longitudinal strain from baseline to completion of neoadjuvant therapy by echocardiography. The secondary endpoints include myocardial diffuse fibrosis (by T1-derived extracellular volume), myocardial edema (by T2 mapping), cardiac volumetric assessment by CMR, diastolic function (by left ventricular volume, left atrial volume, E/A, and E/E') by echocardiography, and exercise capacity by CPET.

Discussion

This study will comprehensively assess the impacts of pyrotinib on myocardial structural, function, and tissue characteristics, and, furthermore, will determine whether pyrotinib plus trastuzumab is a reasonable dual HER2 blockade regimen with regard to cardiac safety. Results may provide information in selecting an appropriate anti-HER2 treatment for HER2-positive breast cancer.

Clinical trial registration

https://clinicaltrials.gov/, identifier NCT04510532.

Breast cancer survivors with preserved or rescued cardiorespiratory fitness have similar cardiac, pulmonary and muscle function compared to controls

Breast cancer survivors (BCS) have a high prevalence of cardiovascular disease and low cardiorespiratory fitness (CRF). CRF is an important predictor of survival in BCS. However, the physiological factors that contribute to low CRF in BCS have not been completely elucidated. To assess differences in physiological factors (cardiac, pulmonary, muscle function) related to CRF between BCS and controls. Twenty-three BCS and 23 age-body mass index (BMI) matched controls underwent a peak cycling exercise test to determine CRF, with physiological factors measured at resting and at peak exercise. Cardiac hemodynamics (stroke volume [SV], SVindex, heart rate [HR], cardiac output [Formula: see text], and [Formula: see text]index) were evaluated using ultrasonography. Pulmonary function was evaluated using the oxygen uptake efficiency slope (OUES), ventilation to carbon dioxide production slope [Formula: see text] and breathing reserve at peak exercise (BR). Muscle oxygenation variables (oxygenated [HbO₂] deoxygenated [HHb] and total hemoglobin [Hb], and tissue oxygenation index [TSI]) were measured with near-infrared spectroscopy (NIRS). Both groups had similar CRF and similarly increased all hemodynamic variables (HR, SV, SVindex, [Formula: see text] and [Formula: see text]index) at peak exercise compared to resting (p < 0.001). BCS had higher overall HR and lower SVindex (group effect, p < 0.05). BCS had similar OUES, [Formula: see text] and BR compared to the controls. Both groups decreased TSI, and increased Hb and HHb similarly at peak exercise compared to resting (p < 0.001). Our data suggest BCS do not exhibit differences in cardiac, pulmonary, or muscle function at peak exercise compared to controls, when both groups have similar CRF and physical activity.

Validity of Estimated Cardiorespiratory Fitness in Patients With Primary Breast Cancer

Background

Estimated peak oxygen consumption (Vo₂peak) is widely used in oncology; however, estimated Vo₂peak equations were developed in noncancer settings.

Objectives

The aim of this study was to evaluate the validity of estimated Vo₂peak in women with primary breast cancer and to develop oncology-specific estimated Vo₂peak equations.

Methods

Vo₂peak was directly measured (TrueOne 2400, Parvo Medics) during 380 cardiopulmonary exercise tests in women previously treated for breast cancer (mean age: 59 ± 10 years; 3.1 ± 1.2 years post-therapy). The American College of Sports Medicine (ACSM), the Fitness Registry and the Importance of Exercise National Database (FRIEND), and heart failure (HF)-FRIEND equations were used to estimate Vo₂peak. New equations were developed using patient and peak (Onc_peak) or submaximal (Onc_sub) exercise test characteristics.

Results

The median differences between measured and estimated Vo₂peak were 7.0 mL O₂·kg⁻¹·min⁻¹, 3.9 mL O₂·kg⁻¹·min⁻¹, and −0.2 mL O₂·kg⁻¹·min⁻¹ for ACSM, FRIEND, and HF-FRIEND, respectively. The number of estimated Vo₂peak values within ±3.5 mL O₂·kg⁻¹·min⁻¹ of the measured values was 70 (18%), 164 (43%), and 306 (81%) for ACSM, FRIEND, and HF-FRIEND, respectively. The Onc_peak and Onc_Sub models included body mass index, age, a history of chemotherapy or radiation, the peak measured heart rate, and the treadmill grade and/or speed. The median differences between measured and estimated Vo₂peak were 0.02 mL O₂·kg⁻¹·min⁻¹ (Onc_peak) and −0.2 mL O₂·kg⁻¹·min⁻¹ (Onc_sub). Eighty-six percent (n = 325) and 76% (n = 283) estimated Vo₂peak values were within ±3.5 mL O₂·kg⁻¹·min⁻¹ of the measured Vo₂peak values for Onc_peak and Onc_sub, respectively.

Conclusions

HF-FRIEND or oncology-specific equations could be applied to estimate Vo₂peak in patients previously treated for breast cancer in settings where cardiopulmonary exercise tests are not available. (Trial Comparing the Effects of Linear Versus Nonlinear Aerobic Training in Women With Operable Breast Cancer [EXCITE]; NCT01186367

Traditional markers of cardiac toxicity fail to detect marked reductions in cardiorespiratory fitness among cancer patients undergoing anti-cancer treatment

AIMS

Left ventricular ejection fraction (LVEF) is standard of care for evaluating chemotherapy-associated cardiotoxicity, although global longitudinal strain (GLS) offers advantages. However, neither change in LVEF or GLS has been associated with short-term symptoms, functional capacity, or long-term heart failure (HF) risk. We sought to determine whether an integrative measure of cardiovascular function (VO2peak) that is strongly associated with HF risk would be more sensitive to cardiac damage induced by cancer treatment than LVEF, GLS, or cardiac biomarkers.

METHODS AND RESULTS

Patients (n = 206, 53 ± 13 years, 35% male) scheduled to commence anti-cancer treatment completed assessment prior to, and within 6 months after therapy. Changes in echocardiographic measures of LV function (LVEF, GLS), cardiac biomarkers (troponin and BNP), and cardiorespiratory fitness (VO2peak) were measured. LV function was normal prior to treatment (LVEF 61 ± 5%; GLS -19.4 ± 2.1), but VO2peak was only 88 ± 26% of age-predicted. After treatment, VO2peak was reduced by 7 ± 15% (equivalent of 7 years normal ageing, P < 0.0001) and the rates of functional disability (defined as VO2peak ≤ 18 mL/min/kg) almost doubled (15% vs. 26%, P = 0.016). In contrast, small, reductions in LVEF (59 ± 5% vs. 58 ± 5%, P = 0.03) and GLS (-19.4 ± 2.1 vs. -18.9 ± 2.2, P = 0.002) and an increase in troponin levels (4.0 ± 6.9 vs. 26.4 ± 26.2 ng/mL, P < 0.0001) were observed.

CONCLUSION

Anti-cancer treatment is associated with marked reductions in functional capacity that occur independent of reductions in LVEF and GLS. The assessment of VO2peak prior to, and following treatment may be a more sensitive means of identifying patients at increased risk of HF.

Exercise Training Preserves Myocardial Strain and Improves Exercise Tolerance in Doxorubicin-Induced Cardiotoxicity

Doxorubicin causes cardiotoxicity and exercise intolerance. Pre-conditioning exercise training seems to prevent doxorubicin-induced cardiac damage. However, the effectiveness of the cardioprotective effects of exercise training concomitantly with doxorubicin treatment remains largely unknown. To determine whether low-to-moderate intensity aerobic exercise training during doxorubicin treatment would prevent cardiotoxicity and exercise intolerance, we performed exercise training concomitantly with chronic doxorubicin treatment in mice. Ventricular structure and function were accessed by echocardiography, exercise tolerance by maximal exercise test, and cardiac biology by histological and molecular techniques. Doxorubicin-induced cardiotoxicity, evidenced by impaired ventricular function, cardiac atrophy, and fibrosis. Exercise training did not preserve left ventricular ejection fraction or reduced fibrosis. However, exercise training preserved myocardial circumferential strain alleviated cardiac atrophy and restored cardiomyocyte cross-sectional area. On the other hand, exercise training exacerbated doxorubicin-induced body wasting without affecting survival. Finally, exercise training blunted doxorubicin-induced exercise intolerance. Exercise training performed during doxorubicin-based chemotherapy can be a valuable approach to attenuate cardiotoxicity.

Long-term Cardiopulmonary Consequences of Treatment-Induced Cardiotoxicity in Survivors of ERBB2-Positive Breast Cancer

Importance

Trastuzumab improves outcomes in patients with ERBB2-positive (formerly HER2) breast cancer but is associated with treatment-induced cardiotoxicity, most commonly manifest by an asymptomatic decline in left ventricular ejection fraction (LVEF). Little is known to date regarding the long-term effects of treatment-induced cardiotoxicity on cardiopulmonary function in patients who survive trastuzumab-treated breast cancer.

Objective

To determine whether treatment-induced cardiotoxicity recovers or is associated with long-term cardiopulmonary dysfunction in survivors of ERBB2-positive breast cancer.

Design, Setting, and Participants

This cross-sectional case-control study enrolled patients with nonmetastatic ERBB2-positive breast cancer after completion of trastuzumab-based therapy (median, 7.0 [interquartile range (IQR), 6.2-8.7] years after therapy) who met 1 of 2 criteria: (1) cardiotoxicity (TOX group) developed during trastuzumab treatment (ie, asymptomatic decrease of LVEF≥10% from baseline to <55% [n = 22]) or (2) no evidence of cardiotoxicity during trastuzumab treatment (NOTOX group [n = 20]). Patients were treated at the Memorial Sloan Kettering Cancer Center. Fifteen healthy control participants (HC group) were also enrolled for comparison purposes. All groups were frequency matched by age strata (<55, 55-64, and ≥65 years). Data were collected from September 9, 2016, to August 10, 2018, and analyzed from November 20, 2018, to August 12, 2019.

Main Outcomes and Measures

Speckle-tracking echocardiography and maximal cardiopulmonary exercise testing were performed to measure indices of left ventricular function (including LVEF and global longitudinal strain [GLS]) and peak oxygen consumption (peak VO2).

Results

A total of 57 participants (median age, 60.8 [IQR, 52.7-65.7] years) were included in the analysis. Overall, 38 of 42 patients with breast cancer (90%) were treated with anthracyclines before trastuzumab. Resting mean (SD) LVEF was significantly lower in the TOX group (56.9% [5.2%]) compared with the NOTOX (62.4% [4.0%]) and HC (65.3% [2.9%]) groups; similar results were found for GLS (TOX group, -17.8% [2.2%]; NOTOX group, -19.8% [2.2%]; HC group, -21.3% [1.8%]) (P < .001). Mean peak VO2 in the TOX group (22.9 [4.4] mL/kg/min) was 15% lower compared with the NOTOX group (27.0 [5.3] mL/kg/min; P = .03) and 25% lower compared with the HC group (30.5 [3.4] mL/ kg/min; P < .001). In patients with breast cancer, GLS was significantly associated with peak VO2 (β coefficient, -0.75; 95% CI, -1.32 to -0.18).

Conclusions and Relevance

Treatment-induced cardiotoxicity appears to be associated with long-term marked impairment of cardiopulmonary function and may contribute to increased risk of late-occurring cardiovascular disease in survivors of ERBB2-positive breast cancer.

Association between systolic ejection time and outcomes in heart failure by ejection fraction

AIMS

Worsening heart failure (HF) is associated with shorter left ventricular systolic ejection time (SET), but there are limited data describing the relationship between SET and clinical outcomes. Thus, the objective was to describe the association between SET and clinical outcomes in an ambulatory HF population irrespective of ejection fraction (EF).

METHODS AND RESULTS

We identified ambulatory patients with HF with reduced EF (HFrEF) and HF with preserved EF (HFpEF) who had an outpatient transthoracic echocardiogram performed between August 2008 and July 2010 at a tertiary referral centre. Multivariable logistic regression was used to evaluate the association between SET and 1-year outcomes. A total of 545 HF patients (171 HFrEF, 374 HFpEF) met eligibility criteria. Compared with HFpEF, HFrEF patients were younger [median age 60 years (25th-75th percentiles 50-69) vs. 64 years (25th-75th percentiles 53-74], with fewer females (30% vs. 56%) and a similar percentage of African Americans (36% vs. 35%). Median (25th-75th percentiles) EF with HFrEF was 30% (25-35%) and with HFpEF was 54% (48-58%). Median SET was shorter (280 ms vs. 315 ms, P < 0.001), median pre-ejection period was longer (114 ms vs. 89 ms, P < 0.001), and median relaxation time was shorter (78.7 ms vs. 93.3 ms, P < 0.001) among patients with HFrEF vs. HFpEF. Death or HF hospitalization occurred in 26.9% (n = 46) HFrEF and 11.8% (n = 44) HFpEF patients. After adjustment, longer SET was associated with lower odds of the composite of death or HF hospitalization at 1 year among HFrEF but not HFpEF patients.

CONCLUSION

Longer SET is independently associated with improved outcomes among HFrEF patients but not HFpEF patients, supporting a potential role for normalizing SET as a therapeutic strategy with systolic dysfunction.

Cytotoxic-induced heart failure among breast cancer patients in Nigeria: A call to prevent today's cancer patients from being tomorrow's cardiac patients

We report three cases of heart failure (HF) associated with the use of cytotoxic drugs such as anthracycline, cyclophosphamide, and 5-fluorouracil in the treatment of breast cancer in Nigerians. The patients had systolic and diastolic HF: HF with reduced ejection fraction and preserved ejection fraction. The prevalence of breast cancer is increasing across Africa, and cytotoxics are some of the most common and best drugs used during management. The cardiotoxicity caused by these drugs limits their use as chemotherapeutic agents. Cytotoxic-induced HF is a preventable and manageable cause of cardiovascular disease (CVD) in Nigeria and Africa. This article discusses the pathophysiology of cytotoxic-induced HF and presents the risk factors that impair cardiovascular function. The importance of proper assessment and the prophylactic and therapeutic measures in the management of cytotoxic-induced HF are emphasized. The peculiar challenges in the management of cytotoxic-induced HF in Nigeria were also discussed. The need for early involvement of cardiologists by oncologists to improve on the chemotherapeutic and cardiovascular outcome in the management of patients with breast cancer was stressed. Perhaps, it is time to birth a new discipline of cardiooncology in Nigeria.

Cardiovascular Consequences of Skeletal Muscle Impairments in Breast Cancer

Breast cancer survivors suffer from disproportionate cardiovascular disease risk compared to age-matched controls. Beyond direct cardiotoxic effects due to treatments such as chemotherapy and radiation, breast-cancer-related reductions in skeletal muscle mass, quality and oxidative capacity may further contribute to cardiovascular disease risk in this population by limiting the ability to engage in aerobic exercise—a known promoter of cardiovascular health. Indeed, 20–30% decreases in peak oxygen consumption are commonly observed in breast cancer survivors, which are indicative of exercise intolerance. Thus, breast-cancer-related skeletal muscle damage may reduce exercise-based opportunities for cardiovascular disease risk reduction. Resistance training is a potential strategy to improve skeletal muscle health in this population, which in turn may enhance the capacity to engage in aerobic exercise and reduce cardiovascular disease risk.

Exercise Intolerance in Anthracycline-Treated Breast Cancer Survivors: The Role of Skeletal Muscle Bioenergetics, Oxygenation, and Composition

BACKGROUND

Peak oxygen consumption (VO2 ) is reduced in women with a history of breast cancer (BC). We measured leg blood flow, oxygenation, bioenergetics, and muscle composition in women with BC treated with anthracycline chemotherapy (n = 16, mean age: 56 years) and age- and body mass index-matched controls (n = 16).

MATERIALS AND METHODS

Whole-body peak VO2 was measured during cycle exercise. 31 Phosphorus magnetic resonance (MR) spectroscopy was used to measure muscle bioenergetics during and after incremental to maximal plantar flexion exercise (PFE). MR imaging was used to measure lower leg blood flow, venous oxygen saturation (Sv O2 ), and VO2 during submaximal PFE, and abdominal, thigh, and lower leg intermuscular fat (IMF) and skeletal muscle (SM).

RESULTS

Whole-body peak VO2 was significantly lower in BC survivors versus controls (23.1 ± 7.5 vs. 29.5 ± 7.7 mL/kg/minute). Muscle bioenergetics and mitochondrial oxidative capacity were not different between groups. No group differences were found during submaximal PFE for lower leg blood flow, Sv O2 , or VO2 . The IMF-to-SM ratio was higher in the thigh and lower leg in BC survivors (0.36 ± 0.19 vs. 0.22 ± 0.07, p = .01; 0.10 ± 0.06 vs. 0.06 ± 0.02, p = .03, respectively) and were inversely related to whole-body peak VO2 (r = -0.71, p = .002; r = -0.68, p = .003, respectively). In the lower leg, IMF-to-SM ratio was inversely related to VO2 and O2 extraction during PFE.

CONCLUSION

SM bioenergetics and oxidative capacity in response to PFE are not impaired following anthracycline treatment. Abnormal SM composition (increased thigh and lower leg IMF-to-SM ratio) may be an important contributor to reduced peak VO2 during whole-body exercise among anthracycline-treated BC survivors.

IMPLICATIONS FOR PRACTICE

Peak oxygen consumption (peak VO2 ) is reduced in breast cancer (BC) survivors and is prognostic of increased risk of cardiovascular disease-related and all-cause mortality. Results of this study demonstrated that in the presence of deficits in peak VO2 1 year after anthracycline therapy, skeletal muscle bioenergetics and oxygenation are not impaired. Rather, body composition deterioration (e.g., increased ratio of intermuscular fat to skeletal muscle) may contribute to reduced exercise tolerance in anthracycline BC survivors. This finding points to the importance of lifestyle interventions including caloric restriction and exercise training to restore body composition and cardiovascular health in the BC survivorship setting.

The Utility of Cardiac Reserve for the Early Detection of Cancer Treatment-Related Cardiac Dysfunction: A Comprehensive Overview

With progressive advancements in cancer detection and treatment, cancer-specific survival has improved dramatically over the past decades. Consequently, long-term health outcomes are increasingly defined by comorbidities such as cardiovascular disease. Importantly, a number of well-established and emerging cancer treatments have been associated with varying degrees of cardiovascular injury that may not emerge until years following the completion of cancer treatment. Of particular concern is the development of cancer treatment related cardiac dysfunction (CTRCD) which is associated with an increased risk of heart failure and high risk of morbidity and mortality. Early detection of CTRCD appears critical for preventing long-term cardiovascular morbidity in cancer survivors. However, current clinical standards for the identification of CTRCD rely on assessments of cardiac function in the resting state. This provides incomplete information about the heart's reserve capacity and may reduce the sensitivity for detecting sub-clinical myocardial injury. Advances in non-invasive imaging techniques have enabled cardiac function to be quantified during exercise thereby providing a novel means of identifying early cardiac dysfunction that has proved useful in several cardiovascular pathologies. The purpose of this narrative review is (1) to discuss the different non-invasive imaging techniques that can be used for quantifying different aspects of cardiac reserve; (2) discuss the findings from studies of cancer patients that have measured cardiac reserve as a marker of CTRCD; and (3) highlight the future directions important knowledge gaps that need to be addressed for cardiac reserve to be effectively integrated into routine monitoring for cancer patients exposed to cardiotoxic therapies.

Usefulness of Global Longitudinal Strain for Early Identification of Subclinical Left Ventricular Dysfunction in Patients With Active Cancer

Cardiotoxicity from cancer therapy has become a leading cause of morbidity and mortality in cancer survivors. The most commonly used definition is cancer therapeutic related cardiac dysfunction defined as a left ventricular ejection fraction (LVEF) reduction of >10%, to a value below 50%. However, according to the recent American and European Society of Echocardiography, global longitudinal strain (GLS) is the optimal parameter for early detection of subclinical left ventricular dysfunction. The objective of this study was to evaluate the frequency of GLS reduction in patients with active cancer and its correlation to other echocardiographic parameters. Data were collected as part of the International Cardio-Oncology Registry. All patients performed at least 2 echocardiograms including GLS. We evaluated the frequency of GLS reduction (≥10% relative reduction), its correlation to LVEF reduction and whether there are other predicting echocardiographic parameters. In 64 consecutive patients, 12 (19%) had ≥10% GLS relative reduction, of which 75% had no concomitant ejection fraction reduction. There were no significant differences in the baseline cardiac risk factors (hypertension, diabetes, hyperlipidemia, or smoking). Treatment with Doxorubicin, Pertuzumab, or Ifosfamide was significantly more frequent in patients GLS reduction. No other echocardiographic parameters, including diastolic function or systolic pulmonary artery pressure were significant predictors for GLS reduction. In conclusion, our study demonstrates that GLS reduction is frequent in active cancer patients, precedes LVEF reduction and cannot be anticipated by other echocardiographic parameters. Using GLS routinely during therapy may lead to an early diagnosis of cardiotoxicity.

Protecting the heart in cancer therapy

Recent advances in cancer prevention and management have led to an exponential increase of cancer survivors worldwide. Regrettably, cardiovascular disease has risen in the aftermath as one of the most devastating consequences of cancer therapies. In this work, we define cancer therapeutics-induced cardiotoxicity as the direct or indirect cardiovascular injury or injurious effect caused by cancer therapies. We describe four progressive stages of this condition and four corresponding levels of prevention, each having a specific goal, focus, and means of action. We subsequently unfold this didactic framework, surveying mechanisms of cardiotoxicity, risk factors, cardioprotectants, biomarkers, and diagnostic imaging modalities. Finally, we outline the most current evidence-based recommendations in this area according to multidisciplinary expert consensus guidelines.

Exercise Therapy and Cardiovascular Toxicity in Cancer

Cardio-oncology is an emerging discipline focused predominantly on the detection and management of cancer treatment-induced cardiac dysfunction (cardiotoxicity), which predisposes to development of overt heart failure or coronary artery disease. The direct adverse consequences, as well as those secondary to anticancer therapeutics, extend beyond the heart, however, to affect the entire cardiovascular-skeletal muscle axis (ie, whole-organism cardiovascular toxicity). The global nature of impairment creates a strong rationale for treatment strategies that augment or preserve global cardiovascular reserve capacity. In noncancer clinical populations, exercise training is an established therapy to improve cardiovascular reserve capacity, leading to concomitant reductions in cardiovascular morbidity and its attendant symptoms. Here, we overview the tolerability and efficacy of exercise on cardiovascular toxicity in adult patients with cancer. We also propose a conceptual research framework to facilitate personalized risk assessment and the development of targeted exercise prescriptions to optimally prevent or manage cardiovascular toxicity after a cancer diagnosis.

Cardio-oncology: the role of advanced echocardiography in cancer patients

INTRODUCTION

Cardio-oncology is a rapidly growing field aimed at improving the quality of care of cancer patients by preventing and monitoring cardiovascular complications resulting from cancer treatment. Cardiac imaging, and in particular, transthoracic echocardiography, plays an essential
role in the baseline assessment and serial follow-up of cardio-oncology patients. Areas covered: This review article discusses the role of cardiac imaging with a focus on advanced echocardiography for the detection and management of cancer therapy related cardiovascular complications, in particular, left ventricular dysfunction and heart failure. Expert commentary: While traditional imaging based assessment of left ventricular ejection fraction still has its place in cardiac monitoring, more advanced echocardiographic modalities, in particular, myocardial deformation imaging with speckle tracking strain analysis, show great potential for detecting early signs of cardiotoxicity. Larger studies are needed to determine both the clinical role of strain measurement in influencing initiation of cardioprotective agents and its prognostic value in long term outcome.

Lifestyle Interventions to Improve Cardiorespiratory Fitness and Reduce Breast Cancer Recurrence

As patients are living longer after a cancer diagnosis, survivorship is becoming increasingly important in cancer care. The sequelae of multimodality therapies include weight gain and decreased cardiorespiratory fitness, which increase cardiovascular risk. Evidence suggests that physical activity reduces the risk of breast cancer recurrence and death. Avoidance of weight gain after therapy also improves outcomes after a diagnosis of breast cancer. Prospective randomized trials must be performed to determine the benefits of specific physical activity and dietary habits for survivors of breast cancer. This review outlines the important physiologic changes that occur with antineoplastic therapy and the important role of exercise and diet.

Reliability of Left Ventricular Ejection Fraction from Three-Dimensional Echocardiography for Cardiotoxicity Onset Detection in Patients with Breast Cancer

BACKGROUND

Cardiotoxicity is a well-known adverse effect of various chemotherapeutic agents that can be monitored by echocardiography. A decrease in left ventricular ejection fraction (LVEF) triggers consideration for therapy modification or interruption. The aim of this study was to evaluate how variability in LVEF estimates computed using three-dimensional echocardiography could influence cardiotoxicity onset detection.

METHODS

One hundred eighty one patients with breast cancer treated with anthracycline and trastuzumab were analyzed. LVEF was computed using two commercial software packages. In a subgroup of 40 patients, three-dimensional echocardiographic data were reanalyzed to assess intra- and interobserver variability by two expert investigators using both packages. Global longitudinal strain (GLS) imaging was evaluated in 64 patients.

RESULTS

End-diastolic volume, end-systolic volume, and LVEF measurements obtained applying the two software packages were in good agreement, with small bias and acceptable limits of agreement. Intra- and interobserver variability was smaller using one of the two software packages. However, for both packages, variability indexes were in the range of affecting LVEF estimates at a level that could lead to an inaccurate assessment of cardiac adverse effects of cancer therapeutic drugs. On the basis of LVEF, 11 of 181 patients (6.1%) had cardiotoxicity at 3-month follow-up. The absolute value of GLS was smaller in 16 of 64 patients (25%) thought to have cardiotoxicity on the basis of GLS results, including six of seven patients who had cardiotoxicity considering LVEF in this subgroup.

CONCLUSIONS

Following clinical definition of cardiotoxicity onset, variability in LVEF computation by three-dimensional echocardiography could be a confounding factor for cardiotoxicity diagnosis, and different software packages should not be used interchangeably for LVEF monitoring. GLS confirms its predictive value for subsequent cardiotoxicity.

Pathophysiology of exercise intolerance in breast cancer survivors with preserved left ventricular ejection fraction

Breast cancer (BC) survival rates have improved during the past two decades and as a result older BC survivors are at increased risk of developing heart failure (HF). Although the HF phenotype common to BC survivors has received little attention, BC survivors have a number of risk factors associated with HF and preserved ejection fraction (HFPEF) including older age, hypertension, obesity, metabolic syndrome and sedentary lifestyle. Moreover, not unlike HFPEF, BC survivors with preserved left ventricular ejection fraction (BCPEF) have reduced exercise tolerance measured objectively as decreased peak oxygen uptake (peak VO₂). This review summarizes the literature regarding the mechanisms of exercise intolerance and the role of exercise training to improve peak VO₂ in BCPEF.

Cardio-oncology: what you need to know now for clinical practice and echocardiography

Cardio-oncology is a rapidly growing field aimed at minimizing the effects of cardiovascular morbidity and mortality in cancer survivors. To meet this aim, patients are assessed at baseline to define their risk of cardiotoxicity and then followed closely during and after chemotherapy to assess for early signs or symptoms of cardiovascular disease. Cardiac imaging, and in particular, transthoracic echocardiography, plays an essential role in the baseline assessment and serial follow-up of cardio-oncology patients. The objectives of this paper are to review the mechanisms of cardiotoxicity of several common chemotherapeutic agents associated with an increased risk for left ventricular systolic dysfunction and to outline recommendations regarding the baseline assessment and serial follow-up of cardio-oncology patients with a focus on the role of echocardiography.

Cardiac dysfunction in cancer survivors unmasked during exercise

BACKGROUND

The cardiac dysfunction associated with anthracycline-based chemotherapy cancer treatment can exist subclinically for decades before overt presentation. Stress echocardiography, the measurement of left ventricular (LV) deformation and arterial haemodynamic evaluation, has separately been used to identify subclinical cardiovascular (CV) dysfunction in several patient groups including those with hypertension and diabetes. The purpose of the present cross-sectional study was to determine whether the combination of these techniques could be used to improve the characterisation of subclinical CV dysfunction in long-term cancer survivors previously treated with anthracyclines.

MATERIALS AND METHODS

Thirteen long-term cancer survivors (36 ± 10 years) with prior anthracycline exposure (11 ± 8 years posttreatment) and 13 age-matched controls were recruited. Left ventricular structure, function and deformation were assessed using echocardiography. Augmentation index was used to quantify arterial haemodynamic load and was measured using applanation tonometry. Measurements were taken at rest and during two stages of low-intensity incremental cycling.

RESULTS

At rest, both groups had comparable global LV systolic, diastolic and arterial function (all P > 0·05); however, longitudinal deformation was significantly lower in cancer survivors (-18 ± 2 vs. -20 ± 2, P < 0·05). During exercise, this difference between groups persisted and further differences were uncovered with significantly lower apical circumferential deformation in the cancer survivors (-24 ± 5 vs. -29 ± 5, -29 ± 5 vs. 35 ± 8 for first and second stage of exercise respectively, both P < 0·05).

CONCLUSION

In contrast to resting echocardiography, the measurement of LV deformation at rest and during exercise provides a more comprehensive characterisation of subclinical LV dysfunction. Larger studies are required to determine the clinical relevance of these preliminary findings.

Cancer Treatment as an Accelerated Aging Process: Assessment, Biomarkers, and Interventions

An accumulating body of evidence supports the hypothesis that cancer and/or cancer treatment is associated with accelerated aging. The majority of these data come from the pediatric literature; however, a smaller yet growing body of literature points toward similar findings in the geriatric population. This is a key survivorship issue the growing number of older adults with cancer face, along with the short- and long-term impact of cancer therapy on the aging process. This article will review clinical and biologic markers of aging in older adults with cancer, use cardiovascular disease as a model of accelerated aging, and discuss potential interventions to decrease the risk.

Cardiac Atrophy and Heart Failure In Cancer

Functional changes in the heart in patients with cancer can be a result of both the disease itself and various cancer therapies, and limiting cardiac damage has become an increasingly important issue as survival rates in patients with cancer have improved. Processes involved in cancer-induced cardiac atrophy may include cardiomyocyte atrophy and apoptosis, decreased protein synthesis, increased autophagy and proteolysis via the ubiquitin-proteosome system. Further to direct effects of malignancy on the heart, several chemotherapeutic agents are known to affect the myocardium, in particular the anthracyclines. The aim of this report is to review the effects of cancer and cancer treatment on the heart and what is known about the underlying mechanisms. Furthermore, clinical strategies to limit and treat cancer-associated cardiac atrophy are discussed, emphasising the benefit of a multidisciplinary approach by cardiologists and oncologists to optimise models of care to improve outcomes for patients with cancer.

Cancer History Portends Worse Acute and Long-term Noncardiac (but Not Cardiac) Mortality After Primary Percutaneous Coronary Intervention for Acute ST-Segment Elevation Myocardial Infarction

OBJECTIVE

To define the effect of a history of cancer on in-hospital and long-term mortality after primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI).

PATIENTS AND METHODS

In this retrospective cohort study of 2346 patients with STEMI enrolled in the Mayo Clinic PCI registry from November 1, 2000, through October 31, 2010, we identified 261 patients (11.1%) with a history of cancer. The in-hospital and long-term outcomes (median follow-up, 6.2 years; interquartile range=4.3-8.5 years), including cardiac and noncardiac death and heart failure hospitalization, of these patients were compared with those of 1313 cancer-negative patients matched on age, sex, family history of coronary artery disease, and date of STEMI.

RESULTS

Patients with cancer had higher in-hospital noncardiac (1.9% vs 0.4%; P=.03) but similar cardiac (5.8% vs 4.6%; P=.37) mortality as matched controls. The group at highest acute mortality risk were those diagnosed as having cancer within 6 months before STEMI (hazard ratio [HR]=7.0; 95% CI, 1.4-34.4; P=.02). At 5 years, patients with cancer had similar cardiac mortality (4.2% vs 5.8%; HR=1.27; 95% CI, 0.77-2.10; P=.35) despite more heart failure hospitalizations (15% vs 10%; HR=1.72; 95% CI, 1.18-2.50; P=.01) but faced higher noncardiac mortality (30.0% vs 11.0%; HR=3.01; 95% CI, 2.33-3.88; P<.001) than controls, attributable solely to cancer-related deaths.

CONCLUSION

One in 10 patients in this contemporary registry of patients undergoing primary PCI for STEMI has a history of cancer. These patients have more than a 3 times higher acute in-hospital and long-term noncardiac mortality risk but no increased acute or long-term cardiac mortality risk with guideline-recommended cardiac care.

Cardiovascular Late Effects and Exercise Treatment in Breast Cancer: Current Evidence and Future Directions

Advances in detection and supportive care strategies have led to improvements in cancer-specific and overall survival after a diagnosis of early-stage breast cancer. These improvements, however, are associated with an increase in competing forms of morbidity and mortality, particularly cardiovascular disease (CVD). Indeed, in certain subpopulations of patients, CVD is the leading cause of mortality after early breast cancer, and these women also have an increased risk of CVD-specific morbidity, including an elevated incidence of coronary artery disease and heart failure compared with their sex- and age-matched counterparts. Exercise treatment is established as the cornerstone of primary and secondary prevention of CVD in multiple clinical populations. The potential benefits of exercise treatment to modulate CVD or CVD risk factors before, immediately after, or in the months/years after adjuvant therapy for early-stage breast cancer have received limited attention. We discuss the risk and extent of CVD in patients with breast cancer, review the pathogenesis of CVD, and highlight existing evidence from select clinical trials investigating the efficacy of structured exercise treatment across the CVD continuum in early breast cancer.

Carvedilol Administration Can Prevent Doxorubicin-Induced Cardiotoxicity: A Double-Blind Randomized Trial

OBJECTIVE

The aim of this study is to evaluate the preventive effects of carvedilol on doxorubicin-induced cardiotoxicity.

METHODS

In this trial, 70 female patients with breast cancer who were candidates to receive doxorubicin were enrolled, from which 30 were selected randomly to receive carvedilol 6.25 mg daily during chemotherapy, with the rest receiving placebo as the control group. Both groups were evaluated 1 week before and 1 week after chemotherapy by measuring the left ventricular ejection fraction and strain/strain rate.

RESULTS

Data analysis showed that the case group presented no significant reduction in strain and strain-rate parameters after intervention, while there was a significant reduction in these parameters in the control group (all p values <0.001). Also, the mean differences of strain parameters in the case group were significantly less than in the control group in all evaluated heart walls (basal septal strain, p = 0.005, basal lateral strain, p = 0.001, basal inferior strain, p < 0.001, and basal anterior strain, p < 0.001); the same was true for the strain-rate parameters (the p values for basal septal, basal lateral, basal inferior and basal anterior strain rate were 0.037, 0.037, 0.002 and <0.001, respectively).

CONCLUSION

This study shows that carvedilol can prevent doxorubicin-induced cardiotoxicity. Whether this prophylaxis should be considered as the preferred method needs further investigation.

Ventricular-Arterial Coupling in Breast Cancer Patients After Treatment With Anthracycline-Containing Adjuvant Chemotherapy

BACKGROUND

Anthracycline-containing chemotherapy (Anth-C) is associated with long-term cardiovascular mortality. Although cardiovascular risk assessment has traditionally focused on the heart, evidence has demonstrated that vascular dysfunction also occurs during and up to 1 year following Anth-C. Whether vascular dysfunction persists long-term or negatively influences cardiac function remains unknown. Hence, the present study evaluated ventricular-arterial coupling, in concert with measures of vascular structure and function, in the years following Anth-C.

METHODS

Arterial elastance (Ea), end-systolic elastance (Ees), and ventricular-arterial coupling (Ea/Ees) were measured during rest and exercise using echocardiography. Resting vascular function (flow-mediated dilation) and structure (carotid intima-media thickness, arterial stiffness) were also measured.

RESULTS

Thirty breast cancer survivors (6.5 ± 3.6 years after Anth-C) with normal left ventricular ejection fraction (LVEF) (60% ± 6%) and 30 matched controls were studied. At rest, no differences were found in Ea, Ees, Ea/Ees, or LVEF between groups. The normal exercise-induced increase in Ees was attenuated in survivors at 50% and 75% of maximal workload (p < .01). Ea/Ees was also higher at all workloads in the survivors compared with the controls (p < .01). No differences in vascular structure and function were observed between the two groups (p > .05).

CONCLUSION

In the years after Anth-C, ventricular-arterial coupling was significantly attenuated during exercise, primarily owing to decreased LV contractility (indicated by a reduced Ees). This subclinical dysfunction appears to be isolated to the heart, as no differences in Ea were observed. The previously reported adverse effects of Anth-C on the vasculature appear to not persist in the years after treatment, as vascular structure and function were comparable to controls.

IMPLICATIONS FOR PRACTICE

Anthracycline-induced cardiotoxicity results in significantly impaired ventricular-arterial coupling in the years following chemotherapy, owing specifically to decreased left ventricular contractility. This subclinical dysfunction was identified only under exercise stress. A comprehensive evaluation of vascular structure and function yielded no differences between those treated with anthracyclines and controls. Combined with a stress stimulus, ventricular-arterial coupling might hold significant value beyond characterization of integrative cardiovascular function, in particular as a part of a risk-stratification strategy after anthracycline-containing chemotherapy. Although vascular function and structure were not different in this cohort, this does not undermine the importance of identifying vascular (dys)function in this population, because increases in net arterial load during exercise might amplify the effect of reductions in contractility on cardiovascular function after anthracycline-containing chemotherapy.

Current and emerging modalities for detection of cardiotoxicity in cardio-oncology

Advancements in diagnostic tools and curative-intent therapies have improved cancer-specific survival. With prolonged survival, patients are now subject to increased aging and development of cardiovascular risk factors such that further improvements in cancer-specific mortality are at risk of being offset by increased cardiovascular mortality. Moreover, established and novel adjuvant therapies used in cancer treatment are associated with unique and varying degrees of direct as well as indirect myocardial and cardiovascular injury (i.e., cardiotoxicity). Current approaches for evaluating anticancer therapy-induced injury have limitations, particularly lack of sensitivity for early detection of subclinical cardiac and cardiovascular dysfunction. With emerging evidence suggesting early prevention and treatment can mitigate the degree of cardiotoxicity and limit interruption of life-saving cancer therapy, the importance of early detection is increasingly paramount. Newer imaging modalities, functional capacity testing and blood biomarkers have the potential to improve early detection of cardiotoxicity and reduce cardiovascular morbidity and mortality.

Subclinical ventricular dysfunction detected by speckle tracking two years after use of anthracycline

Background

Heart failure is a severe complication associated with doxorubicin (DOX) use. Strain, assessed by two-dimensional speckle tracking (2D-STE), has been shown to be useful in identifying subclinical ventricular dysfunction.

Objectives

a) To investigate the role of strain in the identification of subclinical ventricular dysfunction in patients who used DOX; b) to investigate determinants of strain response in these patients.

Methods

Cross-sectional study with 81 participants: 40 patients who used DOX ±2 years before the study and 41 controls. All participants had left ventricular ejection fraction (LVEF) ≥55%. Total dose of DOX was 396mg (242mg/ms²). The systolic function of the LV was evaluated by LVEF (Simpson), as well as by longitudinal (ε_LL), circumferential (ε_CC), and radial (ε_RR) strains. Multivariate linear regression (MLR) analysis was performed using ε_LL (model 1) and ε_CC (model 2) as dependent variables.

Results

Systolic and diastolic blood pressure values were higher in the control group (p < 0.05). ε_LL was lower in the DOX group (-12.4 ±2.6%) versus controls (-13.4 ± 1.7%; p = 0.044). The same occurred with ε_CC: -12.1 ± 2.7% (DOX) versus -16.7 ± 3.6% (controls; p < 0.001). The S’ wave was shorter in the DOX group (p = 0.035). On MLR, DOX was an independent predictor of reduced ε_CC (B = -4.429, p < 0.001). DOX (B = -1.289, p = 0.012) and age (B = -0.057, p = 0.029) were independent markers of reduced ε_LL.

Conclusion

a) ε_LL, ε_CC and the S’ wave are reduced in patients who used DOX ±2 years prior to the study despite normal LVEF, suggesting the presence of subclinical ventricular dysfunction; b) DOX was an independent predictor of reduced ε_CC; c) prior use of DOX and age were independent markers of reduced ε_LL.

Cancer therapy-induced cardiotoxicity: role of ultrasound deformation imaging as an aid to early diagnosis

In the last decade, ultrasound deformation imaging, based on both Doppler and speckle tracking echocardiography techniques, has emerged as a more sensitive tool to identify subtle and subclinical left ventricular systolic dysfunction in several clinical settings compared with ejection fraction. In this article, we review the evidence relative to the application of ultrasound deformation imaging to the oncologic field for detection of left ventricular systolic dysfunction induced by cardiotoxic treatments with the aim of verifying whether this approach may actually help in early diagnosis of chemotherapy-induced cardiotoxicity.

Evaluation, prevention and management of cancer therapy-induced cardiotoxicity: a contemporary approach for clinicians

PURPOSE OF REVIEW

While targeted therapies have improved cancer outcomes, unique cardiovascular toxicities are increasingly recognized, particularly when administered sequentially after anthracyclines or radiation. Patients with cancer therapy-induced cardiotoxicity benefit from collaborative care involving cardiology and oncology, leading to a new interdisciplinary field called cardio-oncology. The present review will highlight contemporary clinical issues in cardio-oncology.

RECENT FINDINGS

Recently, risk factors for cancer therapy-induced cardiotoxicity have been evaluated in real-world rather than in clinical trial patients. Biomarkers and advanced echocardiography are emerging as sensitive tools for preclinical identification of cancer therapy-induced cardiotoxicity. Single-center studies suggest that cancer therapy-induced cardiotoxicity responds to prompt heart failure medical treatment, and such therapy may even prevent cardiotoxicity.

SUMMARY

Modern cancer therapy has short-term cardiac risk that may require collaborative management by clinicians with expertise in cardiology and oncology. The increased effectiveness of modern cancer therapy is resulting in a growing population of cancer survivors who are at long-term risk for cardiovascular disease. The present review of contemporary clinical issues in cardio-oncology will be of interest to healthcare providers who manage cardiotoxicity during cancer therapy, and who follow patients who survive cancer but face increased long-term cardiovascular risk.

Prevention and Treatment of Cardiac Dysfunction in Breast Cancer Survivors

As recurrence free survival following a breast cancer diagnosis continues to improve, cardiovascular morbidity and mortality will assume greater importance in the breast cancer survivorship research agenda particularly for women receiving potentially cardiotoxic therapy. Development of (1) tools to readily identify pre-diagnostic risk factors for cardiac dysfunction, (2) well-tolerated prophylactic treatments to reduce the risk of cardiac injury, and (3) sensitive and affordable monitoring techniques which can identify subclinical toxicity prior to a drop in left ventricular ejection fraction are or should be focus areas of cardio-oncology research. Since weight as well as cardiorespiratory fitness generally decline after a breast cancer diagnosis, behavioral approaches which can improve energy balance and fitness are important to optimize cardiovascular health in all breast cancer survivors not just those undergoing cardiotoxic therapy. These goals are likely best achieved by partnerships between cardiologists, oncologists and internists such as those initiated with the formation of the International CardiOncology Society (ICOS) and the NCI Community Cardiotoxicity Task Force.

Quantitative measures of physical functioning after autologous hematopoietic stem cell transplantation in multiple myeloma: a feasibility study

BACKGROUND

The safety and feasibility of the symptom-limited cardiopulmonary exercise test (CPET) and the 6-minute walk test (6MWT) has not been rigorously tested in patients with multiple myeloma (MM) after high-dose chemotherapy with autologous stem cell transplantation (ASCT), nor have correlations with patient-reported outcomes (PROs) been explored.

PATIENTS AND METHODS

We undertook CPET, 6MWT, and PRO assessments using standardized measurements and questionnaires in patients with MM in remission after ASCT.

RESULTS

A total of 22 patients who were a median of 17 months after ASCT underwent assessment. No severe adverse events were observed. Exercise capacity, measured during CPET as the peak oxygen consumption, was 17.5 ± 5.9 mL/kg/min, the equivalent of 38% ± 18% less than that for age- and sex-predicted sedentary normative values. During the 6MWT, the mean 6-minute walk distance was 500 m, or 25% ± 13% less than the predicted values. Additional analysis using Pearson's correlation revealed no significant univariate associations between exercise or functional capacity and any PROs.

CONCLUSION

Patients with MM have marked and significant reductions in quantitative measures of physical function for years after the initial therapy, although that did not correlate with PROs in the present pilot study. Larger prospective studies are required to determine the clinical ramifications of these findings and to mechanistically dissect them, as well to test interventions aimed at mitigating them.