Evaluation of the Left Ventricular Function with Tissue Tracking and Tissue Doppler Echocardiography in Pediatric Malignancy Survivors after Anthracycline Therapy

The role of conventional echocardiographic parameters on detecting subclinical anthracycline therapy related cardiac dysfunction—The SATRACD study

Background

Subclinical anthracycline therapy related cardiac dysfunction (ATRCD) can be detected with speckle tracking echocardiographic image (STE), which is not widely available in Uganda. We aimed to investigate the role of the two conventional echocardiographic parameters [mitral annular plane systolic excursion (MAPSE) and mitral annular peak systolic tissue Doppler velocity (S’)] on diagnosing subclinical ATRCD.

Method and results

207 cancer patients who underwent anthracycline based chemotherapy were recruited at baseline and followed up until 6 months after ending anthracycline therapy. Comprehensive echocardiographic data were collected at each visit. Global longitudinal strain (GLS) by STE was used as the gold standard diagnostic test to define the case of subclinical ATRCD. Data of the 200 patients who had no evidence of clinical ATRCD were analyzed. One hundred and seventy-two (86.0%) were female, with a median age of 42 years and 47 (23.5%) patients were diagnosed with subclinical ATRCD at the end of anthracycline therapy by GLS criteria. The area under the curve (AUC), cutoff point, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of reduction of MAPSE (ΔMAPSE) were 0.6736 (95% CI: 0.5885, 0.7587), ≥ 2 mm, 74.5% (95% CI: 59.7%, 86.1%), 54.9% (95% CI: 46.7%, 63.0%), 33.7% (95% CI: 24.7%, 43.6%), and 87.5% (95% CI: 79.2%, 93.4%). The AUC, cutoff point, sensitivity, specificity, PPV, and NPV of reduction of S’ (ΔS’) were 0.6018 (95% CI: 0.5084, 0.6953), ≥ 0.5 cm/s, 61.7% (95% CI: 46.4%, 75.5%), 52.7% (95% CI: 44.4%, 60.9%), 29.0% (95% CI: 20.4%, 38.9%), and 76.1% (95% CI: 72.4%, 88.6%). When ΔMAPSE and ΔS’ are used as parallel test, the net sensitivity and specificity is 89.4% and 28.8%, respectively, the net PPV and NPV is 27.8% and 90.0%, respectively.

Conclusion

The ΔMAPSE and ΔS’ showed fairly good accuracy, sensitivity and NPV to detect subclinical ATRCD in Ugandan cancer patients. These conventional echocardiographic parameters may serve as screening tools for detecting subclinical ATRCD in resource limited settings.

Cardiac Surveillance for Early Detection of Late Subclinical Cardiac Dysfunction in Childhood Cancer Survivors After Anthracycline Therapy

BACKGROUND

In childhood cancer survivors (CCSs) anthracycline-related cardiotoxicity is an important cause of morbidity and late mortality, but the optimal modality of cardiac surveillance still remains to be defined. The aim of this study was to assess whether non-invasive echocardiography-based functional cardiac measures can detect early subclinical myocardial changes in long-term pediatric cancer survivors who received anthracycline therapy.

METHODS

Twenty anthracycline-treated long-term CCSs and 20 age, sex, and body surface area matched healthy controls were enrolled in this study. Among cancer survivors, mean age at diagnosis was 6.5 ± 4.4 years, and the mean cumulative anthracycline dose was 234.5 ± 87.4 mg/m2. All subjects underwent a comprehensive functional echocardiographic protocol study including two-dimensional echocardiography (2D Echo), tissue Doppler imaging (TDI), speckle tracking (STE) and three-dimensional echocardiography (3D Echo). Patients were studied at a mean follow-up time of 6.5 ± 2.8 years from the end of therapy.

RESULTS

No significant differences in two-dimensional left ventricle ejection fraction (LVEF), diastolic parameters and speckle tracking (STE)-derived myocardial strain were observed between patients treated with anthracyclines and controls. Myocardial performance index was significantly prolonged (p = 0.005) and three-dimensional LVEF was significantly reduced (p = 0.002) in CCSs compared to controls, even though most values were within the normal range. There were no significant correlations between 2D, STE, and 3D echocardiographic parameters and age at diagnosis or duration of follow-up. No significant differences in echocardiographic parameters were found when stratifying cancer patients according to established risk factors for anthracycline cardiomyopathy.

CONCLUSIONS

This study found significantly reduced three-dimensional LVEF in CCSs compared with controls, despite no significant differences in two-dimensional LVEF and longitudinal strain values. These findings suggest that long-term CCSs who had received anthracycline therapy may be found to have subclinical features of myocardial dysfunction. However, further studies are needed to demonstrate the validity of new imaging techniques, including STE and 3D Echo, to identify patients at risk for cardiomyopathy in the long-term follow-up of CCSs.

Cardiac left ventricular ejection fraction in men and women with schizophrenia on long-term antipsychotic treatment

Patients with schizophrenia exhibit a higher cardiovascular mortality compared to the general population which has been attributed to life-style factors, genetic susceptibility and antipsychotic medication. Recent echocardiographic studies have pointed to an association between clozapine treatment and reduced left ventricular ejection fraction (LVEF), a measure that has been inversely associated with adverse outcomes including all-cause mortality. Cardiovascular magnetic resonance (CMR) is considered the reference method for LVEF measurement. The aim of the present study was to investigate the LVEF in patients with schizophrenia on long-term treatment with antipsychotics and healthy controls. Twenty-nine adult patients with schizophrenia on long-term medication with antipsychotics and 27 age-, sex- and body mass index-matched healthy controls (mean ages 44 and 45 years, respectively) were recruited from outpatient psychiatric clinics in Uppsala, Sweden. The participants were interviewed and underwent physical examination, biochemical analyses, electrocardiogram and CMR. Men with schizophrenia on long-term antipsychotic treatment showed significantly lower LVEF than controls (p = 0.0076), whereas no such difference was evident among women (p = 0.44). Specifically, clozapine-treated male patients had 10.6% lower LVEF than male controls (p = 0.0064), whereas the LVEF was 5.5% below that of controls among male patients treated with non-clozapine antipsychotics (p = 0.047). Among medicated men with schizophrenia, we found significantly lower LVEF compared to healthy individuals, suggesting the need of routine cardiac monitoring in this patient group. This is the first study showing a significant negative association between treatment with non-clozapine antipsychotics and LVEF.

Longitudinal Changes in Echocardiographic Parameters of Cardiac Function in Pediatric Cancer Survivors

Objectives

The purpose of this study was to assess the timing of changes in serial echocardiographic parameters in pediatric cancer survivors and to evaluate their associations with cardiomyopathy development.

Background

Pediatric cancer survivors undergo serial echocardiograms to screen for cardiotoxicity. It is not clear whether small longitudinal changes in functional or structural parameters over time have clinical significance.

Methods

This is a multicenter, retrospective, case-control study of ≥1-year survivors following the end of cancer therapy. Cardiomyopathy cases (fractional shortening [FS] ≤28% or ejection fraction [EF] ≤50% on ≥2 occasions) were matched to control subjects (FS ≥30%, EF ≥55%, not on cardiac medications) by cumulative anthracycline and chest radiation dose, follow-up duration, and age at diagnosis. Digitally archived clinical surveillance echocardiograms were quantified in a central core laboratory, blinded to patient characteristics. Using mixed models with interaction terms between time and case status, we estimated the least square mean differences of 2-dimensional, M-mode, pulsed wave Doppler, and tissue Doppler imaging–derived parameters over time between cases and control subjects.

Results

We identified 50 matched case-control pairs from 5 centers. Analysis of 412 echocardiograms (cases, n = 181; control subjects, n = 231) determined that indices of left ventricular systolic function (FS, biplane EF), diastolic function (mitral E/A ratio), and left ventricular size (end-diastolic dimension z-scores) were significantly different between cases and control subjects, even 4 years prior to the development of cardiomyopathy.

Conclusions

Longitudinal changes in cardiac functional parameters can occur relatively early in pediatric cancer survivors and are associated with the development of cardiomyopathy.

Subclinical Cardiac Dysfunction in Childhood Cancer Survivors on 10-Years Follow-Up Correlates With Cumulative Anthracycline Dose and Is Best Detected by Cardiopulmonary Exercise Testing, Circulating Serum Biomarker, Speckle Tracking Echocardiography, and Tissue Doppler Imaging

Background: Survivors of childhood cancer are at risk for anthracycline- and/or radiotherapy-induced cardiotoxicity. Aims: The aim of this study was to assess clinical, laboratory, and imaging parameters of subclinical cardiovascular disease in childhood cancer survivors. Methods: Patients underwent cardiopulmonary exercise test (CPET), laboratory testing, transthoracic echocardiography (TTE) with tissue doppler imaging (TDI) and speckle tracking. A subset of patients also underwent cardiovascular magnetic resonance imaging (CMR). Findings were correlated to cumulative anthracycline and exposure to mediastinal irradiation during cancer treatment. In a subgroup analysis, TTE and CMR findings were compared to data from 40 gender- and age-matched patients with childhood onset hypertrophic cardiomyopathy (HCM). Results: Cardiac evaluation was performed in 79 patients (43 males) at 11.2 ± 4.5 years after cancer treatment. Oncologic diagnosis at a median age of 12.0 years was Hodgkin lymphoma in 20, sarcoma in 17, acute leukemia in 24, relapse leukemia in 10, and others in 8 patients. Cumulative anthracycline dose exceeded 300 mg/m² in 28 patients. Twenty six patients also received mediastinal irradiation. Decreased peak respiratory oxygen uptake in % predicted on CPET, increased levels of N-terminal pro-brain natriuretic peptide (NTproBNP), increased global longitudinal strain on TTE speckle tracking, and diastolic dysfunction on TDI were the most prominent findings on detailed cardiology follow-up. In contrast to HCM patients, childhood cancer survivors did not show left ventricular hypertrophy (LVPWd z-score median 0.9 vs. 2.8, p < 0.001), hyperdynamic systolic function on TTE (Ejection fraction 62 ± 7 vs. 72 ± 12%, p = 0.001), or fibrotic myocardial changes on CMR (Late gadolinium positive 0/13 vs. 13/36, p = 0.001; extracellular volume fraction 22 ± 2 vs. 28 ± 3, p < 0.001) at time of follow-up. There was no correlation between chest radiation exposure and abnormal cardiac findings. Cumulative anthracycline dose was the only significant independent predictor on multivariate analysis for any cardiovascular abnormality on follow-up (p = 0.036). Conclusion: Increasing cumulative anthracycline dose during cancer treatment correlates with subclinical cardiac dysfunction in childhood cancer survivors best detected by elevated cardiac serum biomarkers, decreased exercise capacity on CPET, and abnormalities on echocardiographic speckle tracking and TDI.

Is health status impaired in childhood cancer survivors? A systematic review and meta-analysis

BACKGROUND

An increase in survival rates of childhood cancer is associated with long-term health issues in survivors.

METHODS

We conducted a systematic review and meta-analysis comparing health status-related endpoints in childhood cancer survivors (CCS) versus controls.

RESULTS

Eighty-six studies (n = 98,480 participants, 62% CCS) were included in the review. Of these, 73 studies (n = 96,550, 63% CCS) could be meta-analyzed. CCS showed a lower left ventricular ejection and fractional shortening (SMD=-0.59 and -0.55, respectively, both p < 0.01 [n=1,824 and 1,880]), a lower HDL-cholesterol concentration (SMD=-0.48, p<0.001, n=1,378) and a higher waist-to-hip ratio (SMD=0.61, p < 0.01, n=229) than their healthy peers. No significant differences were found for the remaining endpoints.

CONCLUSIONS

CCS is associated with a lower left ventricular function and HDL-cholesterol level, and a higher waist-to-hip ratio than healthy controls. These findings support the need to closely monitor the cardiometabolic health status of CCS and to implement preventive lifestyle interventions for this population.

Evaluation of long-term cardiac side effects of anthracycline chemotherapy by conventional and non-conventional echocardiographic methods in childhood cancer survivors

OBJECTIVE

Anthracycline chemotherapeutic agents carry the well-recognised risk of cardiac toxicity. The aim of this study was to determine the long-term effect of anthracycline chemotherapy on the biventricular function in childhood cancer survivors using tissue Doppler imaging and two-dimensional speckle tracking echocardiography.

PATIENTS AND METHODS

The study included 45 survivors of childhood cancers and 50 healthy age-matched control patients. Cardiac function was prospectively studied with conventional echocardiography, tissue Doppler imaging, and speckle tracking echocardiography after completion of treatment. The same analysis was performed on matched controls.

RESULTS

There was no difference in age, gender, height, and weight between the study and control groups. The mean anthracycline dose was 240 ± 106 mg/m2 and the mean remission duration was 8.2 ± 5 years (1-20 years) in the study group. Conventional echocardiography showed similar ejection fraction, shortening fraction, and left ventricle end-diastolic diameter in both groups. Mitral lateral and septal tissue Doppler imaging showed normal but according to control group relatively sub-normal systolic and diastolic function in patient group. The global longitudinal and circumferential strain and strain rates were significantly lower in the patient group compared to control group. Correlation analysis revealed a negative and significant correlation between total anthracycline dose and global longitudinal and circumferential strain and strain rates.

CONCLUSION

Sub-clinical systolic and diastolic dysfunction may not be detected by conventional echocardiographic methods which are frequently used in daily practice. Sub-clinical systolic and diastolic dysfunction may be detected more sensitively by echocardiographic method such as speckle tracking echocardiography in childhood cancer survivors.

Tissue Doppler Imaging for anthracycline cardiotoxicity monitoring in pediatric patients with cancer

BACKGROUND

Cardiotoxic effects of anthracycline therapy are a major cause of morbidity for childhood cancer survivors. The aim of this retrospective evaluation is to assess the efficacy of Tissue Doppler Imaging in the early detection of myocardial alterations in these patients.

METHODS

A population of 50 childhood cancer survivors (32 males and 18 females) who have been treated with anthracyclines was evaluated by standard and TDI echocardiographic examination of the basal and median region of the interventricular septum (IVSb, IVSm), of the left ventricular posterior wall (LVPWb, LVPWm), and of the mitral annulus; the results were compared with those obtained from a population of 50 healthy age-matched and sex-matched controls by using the Student test. The clinical and echocardiographic data of the two groups were compared also with the independent samples t-test. All data were expressed as mean ± standard deviation. A two-tailed P-value < 0.05 was considered statistically significant. Statistical analysis was performed using STATA 7.0.

RESULTS

The case-control analysis showed statistically significant differences (p < 0,05) between the patients and the controls values. The systolic performance of the patients was normal (LVEF (p = 0,0029) and LVFS (p = 0,0002)). Statistically significant differences between patients and controls were found for diastolic function measurements obtained with PW Doppler such as IVRT (p = 0,0000), DT (p = 0,0041), E (p = 0,0000), A (p = 0,0458), even if E/A ratio was not altered. TDI analysis also show significant differences between patients and controls in both LVPW and IVS (basal and middle segments); E/E' ratio and E'/A' ratio did not vary significantly. Linear Regression and multivariate analysis showed that Hematopoietic Stem Cell Transplantation had the highest impact on our measurements.

CONCLUSIONS

The results showed a myocardial diastolic impairment with preserved ejection fraction. Since the median follow-up time of our cohort was 2 years, further evaluation is needed to better define the diastolic alterations. TDI analysis showed high sensitivity for the detection of mild myocardial dysfunction; the implementation of this novel method as standard practice in the follow-up of selected childhood cancer survivors might help to achieve a better management of long-term complications of cardiotoxic chemotherapy.

Myocardial stiffness as assessed by diastolic wall strain in adult survivors of childhood leukaemias with preserved left ventricular ejection fraction

Aims

We tested the hypothesis that myocardial stiffness as assessed by diastolic wall strain (DWS) is altered in adult survivors of childhood leukaemias with preserved left ventricular (LV) ejection fraction and explored its association with myocardial fibrosis and diastolic deformation.

Methods and results

Ninety-four (53 males) adult survivors of childhood leukaemias aged 22.2 ± 5.5 years and 66 (36 males) healthy controls were studied retrospectively. Diastolic wall strain and calibrated integrated backscatter (cIB) were measured as indices of myocardial stiffness and fibrosis, respectively. Left and right ventricular (RV) diastolic and torsional mechanics were interrogated using speckle tracking echocardiography. Patients had significantly lower LV DWS, and hence stiffer LV myocardium, and greater myocardial cIB in patients than controls (all P < 0.001). Left ventricular longitudinal, radial, and circumferential early diastolic strain rates, circumferential late diastolic strain rate, and peak twisting and untwisting velocities, tricuspid annular early diastolic velocity, and RV-free wall longitudinal early diastolic strain rate were significantly lower in patients than controls (all P < 0.05). Diastolic wall strain correlated inversely with myocardial cIB, and positively with LV longitudinal, radial, and circumferential early diastolic strain rates (all P < 0.05), while myocardial cIB correlated inversely with LV radial and circumferential early diastolic strain rates, circumferential late diastolic strain rate, peak twisting and untwisting velocities, and tricuspid annular e velocity (all P < 0.05).

Conclusion

In adult survivors of childhood leukaemias, despite the preservation of LV ejection fraction, increased stiffness of the LV myocardium is evident and is associated with myocardial fibrosis and impaired ventricular diastolic function.

Cardiovascular imaging in the diagnosis and monitoring of cardiotoxicity: role of echocardiography

The evaluation by cardiovascular imaging of chemotherapy patients became a central topic in the last several years. The use of drugs for the treatment of cancers increased, and new molecules and protocols were developed to improve outcomes in these patients. Although, these novel approaches also produced a progressive increase in side effects, particularly myocardial dysfunction. Imaging of the heart was highly accurate in the early diagnosis of cancer therapeutics related-cardiac dysfunction. Echocardiography is the first-line method to assess ventricular function alterations, and it is required to satisfy the need for an early, easy and accurate diagnosis to stratify the risk of heart failure and manage treatments. A careful monitoring of cardiac function during the course of therapy should prevent the onset of severe heart impairment. This review provides an overview of the most important findings of the role of echocardiography in the management of chemotherapy-treated patients to create a clear and complete description of the efficacy of conventional measurements, the importance of comprehensive heart evaluations, the additional role of new echocardiographic techniques, the utility of integrated studies using other imaging tools and the positions of the most important international societies on this topic.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cancer treatment-related cardiac toxicity: prevention, assessment and management

Cancer therapies, especially anthracyclines and monoclonal antibodies, have been linked with increased rates of cardiotoxicity. The development of some cardiac side effects happens over several months, and changes in ejection fraction can be detected long before permanent damage or disability occurs. Advanced heart failure could be averted with better and earlier detection. Methodologies for early detection of cardiac changes include stress echocardiograms, cardiac velocity measurements, radionuclide imaging, cardiac MRI and several potential biomarkers. Many agents have been described for prophylaxis of cardiac events precipitated by cancer therapy. Prophylactic use of beta-blockers and ACE inhibitors may be considered for use with trastuzumab in breast cancer as tolerated. Recovery of cardiac function is possible early after the injury from a cancer therapy. Late complications for coronary artery disease, hypertension and arrhythmia are underappreciated. Treatments for severe cancer therapy-related cardiac complications follow the existing paradigms for congestive heart failure and coronary artery disease, although outcomes for cancer patients differ from outcomes for non-cancer patients.

Echocardiographic Detection of Cardiac Dysfunction in Childhood Cancer Survivors: How Long Is Screening Required?

BACKGROUND

Childhood cancer survivors treated with anthracycline chemotherapy are at an increased risk of long-term cardiac toxicity, and guidelines recommend that exposed survivors undergo echocardiography every 1-5 years. However, it is unclear whether survivors should undergo echocardiographic screening indefinitely, or if a period of echocardiographic stability indicates that screening is no longer necessary. The objective of this study was to evaluate the outcomes of echocardiographic screening to aid in the refinement of existing guidelines.

METHODS

We retrospectively analyzed the results of echocardiographic screening in a cohort of adult survivors of childhood cancer treated with anthracyclines and/or cardiac radiation therapy. Interval regression analysis was performed to identify predictors of single-episode or sustained abnormal echocardiograms.

RESULTS

The cohort constituted 333 survivors, with median follow-up time of 15.8 years post-treatment (range: 5.0-47.9), and median age at treatment of 8 years (range: 1.5-18). Forty-nine survivors had an abnormal echocardiogram (14.7%), and 29 (8.7%) had reproducible abnormal findings. An ongoing continual increase in the incidence of sustained echocardiographic abnormality was seen among patients treated with >250 mg/m(2) doxorubicin at age <5 years, reaching 43% by 20 years of therapy. In contrast, no sustained abnormal echocardiographic findings arose after 10 years of therapy in survivors treated with <250 mg/m(2) at age ≥5 years.

CONCLUSIONS

Single-episode echocardiographic abnormalities are often not reproduced in subsequent evaluations. The duration of echocardiographic screening for childhood cancer survivors should be reassessed for patients who received lower doses of anthracycline after age 5.

Impairment of left ventricular function early in treatment with clozapine: a preliminary study

This preliminary prospective study evaluated cardiac status in 15 treatment-resistant schizophrenia patients (aged 18-55 years) without evidence of cardiovascular disease. Patients underwent clinical assessment, blood tests, ECG, and echocardiography before and during clozapine treatment for 4 weeks as doses increased from 25 to 100 mg/day. Serum concentrations of high-sensitivity C-reactive protein, troponin-I, brain natriuretic peptide, and clozapine+norclozapine were assayed at week 3; ECG and echocardiography were repeated at week 4. At moderate serum drug concentrations (124 ng/ml), the heart rate increased by 10% and high-sensitivity C-reactive protein levels were slightly elevated, but troponin-I and brain natriuretic peptide levels were not elevated. Echocardiographic indices indicated declining left ventricular (LV) diastolic and systolic function in 60-80% of participants, with an increase in systolic pulmonary artery pressure, A-wave velocity, and LV myocardial performance index by 16-24% in 60-80% of participants and a decrease in the E/A ratio by 29% in 73% of participants - all uncorrelated with drug concentrations. Early treatment with moderate doses of clozapine was associated with subclinical but substantial decreases in LV functioning in surprisingly high proportions of participants. Studies with more participants, higher drug doses, and long-term follow-up are needed to confirm and determine the course of the observed abnormalities and to evaluate their relationship with rare clinical cardiotoxicity associated with clozapine.

Diastolic function in anthracycline-treated children

BACKGROUND

Anthracyclines are effective medications for childhood cancer. Their limitation is the risk of cardiomyopathy. Although diastolic dysfunction has been described in patients who received anthracyclines, cardiac monitoring has focused on systolic function, which is abnormal in up to 41% of the patients. We conducted a study to assess diastolic function utilising transmitral inflow Doppler velocities and tissue Doppler imaging in anthracycline-treated children 5 years post-therapy.

METHODS

This was a retrospective study on 63 anthracycline-treated patients. Echocardiographic parameters included peak early and late transmitral inflow Doppler velocities (E, A), E/A ratio, E deceleration time, and tissue Doppler imaging early and late diastolic mitral annulus velocities (E', A'), E/E' ratio, and E'/A' ratio.

RESULTS

All indices of diastolic function that we measured were normal in the anthracycline-treated patients.

CONCLUSION

We conclude that diastolic function assessed by transmitral inflow Doppler velocities and tissue Doppler imaging is normal in anthracycline-treated children 5 years after completion of treatment. Further longitudinal study is needed to determine whether diastolic function becomes abnormal with time in this patient population.

Evaluation of cardiotoxicity by tissue Doppler imaging in childhood leukemia survivors treated with low-dose anthracycline

Improvement in long-term survival in patients with acute childhood leukemia has led to the need for monitorization of chemotherapy-related morbidity and mortality. This study included 60 patients with acute lymphoblastic leukemia that were in remission for at least 2 years and 30 healthy controls. Systolic and diastolic function of myocardium was evaluated using conventional echocardiography and tissue Doppler imaging of the left ventricle, interventricular septum and right ventricle. Median age of patients was 11.7 years (range 10-14.9 years), and the median duration of remission was 4 years (range 2.5-5 years). All patients were treated with a low cumulative dose of adriamycin (100 mg/m(2)) according to the St. Jude Total-XIIIA protocol. The ejection fraction (EF) and fractional shortening were normal in the patient and control groups, even though EF values were significantly lower in the patients (69.5 ± 2.3 vs. 72.7 ± 3 %, P < 0.01). Myocardial systole (S m), early diastole (E m) and late diastole (A m) velocities in all segments of the myocardium were significantly lower in the patient group (P < 0.01 for all segments). Cardiotoxicity was noted in all segments of the myocardium in the patient group, despite the fact that they were all treated with a low cumulative dose of adriamycin. Based on these findings, we think that there is no safe dose for anthracyclines and periodic echocardiographic evaluation of both the left and right ventricles must be performed in all patients treated with anthracyclines, even at low doses.

Managing chemotherapy-related cardiotoxicity in survivors of childhood cancers

In the US, children diagnosed with cancer are living longer, but not without consequences from the same drugs that cured their cancer. In these patients, cardiovascular disease is the leading cause of non-cancer-related morbidity and mortality. Although this review focuses on anthracycline-related cardiomyopathy in childhood cancer survivors, the global lifetime risk of other cardiovascular diseases such as atherosclerosis, arrhythmias and intracardiac conduction abnormalities, hypertension, and stroke also are increased. Besides anthracyclines, newer molecularly targeted agents, such as vascular endothelial growth factor receptor and tyrosine kinase inhibitors, also have been associated with acute hypertension, cardiomyopathy, and increased risk of ischemic cardiac events and arrhythmias, and are summarized here. This review also covers other risk factors for chemotherapy-related cardiotoxicity (including both modifiable and non-modifiable factors), monitoring strategies (including both blood and imaging-based biomarkers) during and following cancer treatment, and discusses the management of cardiotoxicity (including prevention strategies such as cardioprotection by use of dexrazoxane).

Screening for cardiac dysfunction in anthracycline-exposed childhood cancer survivors

PURPOSE

To examine the utility and reliability of obtaining early echocardiographic measurements of left ventricular (LV) remodeling as well as blood biomarkers of cardiac injury in asymptomatic childhood cancer survivors at risk for LV dysfunction and congestive heart failure due to past exposure to anthracycline chemotherapy.

EXPERIMENTAL DESIGN

Using a cross-sectional design, anthracycline-exposed childhood cancer survivors with preserved ejection fraction (EF; ≥50%) were evaluated using early echocardiographic indices and blood biomarkers of LV dysfunction. Survivors treated with ≥300 mg/m(2) anthracyclines [high risk (HR): n = 100] were compared with those treated with <300 mg/m(2) anthracyclines [low risk (LR): n = 50] and matched healthy controls (HC: n = 50). All echocardiograms were interpreted by an institutional cardiologist and a study cardiologist blinded to risk status.

RESULTS

Time from diagnosis was comparable for HR (12.0 years) and LR (13.2 years, P = 0.8) survivors. Echocardiograms: HR had lower LV thickness-dimension ratio (Z-score: HR: -0.62, LR: -0.03, HC: -0.02; P < 0.001), increased LV wall stress (HR: 66.7 g/cm(2), LR: 56.6 g/cm(2), HC: 54.2 g/cm(2); P < 0.01), and higher myocardial performance index (HR: 0.51, LR: 0.46, HC: 0.46; P < 0.01). Interobserver correlation (clinical/blinded reading) for all echocardiographic indices was excellent (range: R = 0.76-0.97, P < 0.001). Blood biomarkers: With the exception of NT-proBNP (r = 0.28, P < 0.01), there was no correlation between blood biomarkers (B-type natriuretic peptide, Troponin-T, ST-2, Galectin-3) and LV dysfunction.

CONCLUSION

Childhood cancer survivors with preserved EF 10+ years from anthracycline exposure had dose-dependent changes in echocardiographic markers of LV dysfunction.

Cardiac complications of chemotherapy: role of imaging

OPINION STATEMENT

New advances in cancer diagnosis and treatment have increased survival rates in patients with cancer. In parallel with this increase in the number of cancer survivors is an increasing prevalence of cardiac complications from cancer treatment. Chemotherapy-induced cardiac dysfunction is a major contributor to adverse morbidity and mortality rates in cancer patients. Evidence suggests that both clinical symptoms and the traditional left ventricular ejection fraction (LVEF) may lack sensitivity as measures of cardiotoxicity. The early identification of subclinical LV dysfunction is becoming increasingly important, as this may allow cancer patients and their physicians to make informed decisions about therapeutic options. The features of echocardiography make it a useful tool in the diagnosis and monitoring of cardiotoxicity. This review will examine the role of cardiac imaging in detecting cardiotoxicity, focusing primarily on the conventional and more recent echocardiographic approaches for assessing subclinical cardiotoxicity.

Assessment of early-onset chronic progressive anthracycline cardiotoxicity in children: different response patterns of right and left ventricles

We aimed to assess early-onset chronic progressive cardiotoxicity in the left and right ventricles with increasing cumulative anthracycline doses. We evaluated 72 patients within the first year after doxorubicin and/or daunorubicin treatment (median 1.3 months; range 0.3-11.5) and 31 healthy controls. Pretreatment and posttreatment QT interval analyzes were performed in 27 newly diagnosed patients. The echocardiographic data of all examinations of 72 patients were classified into three groups according to instant cumulative anthracycline doses: treatment group (TG)-I (≤120 mg/m(2); n = 26), TG-II (120-240 mg/m(2); n = 39), and TG-III (≥240 mg/m(2); n = 40). Diastolic and systolic parameters were analyzed by conventional echocardiography and tissue Doppler imaging (TDI) and compared with those of healthy controls. The mean age for patients and controls was 8.2 ± 4.5 and 9.6 ± 4.2 years, respectively (p > 0.05). QTc dispersion significantly increased after anthracycline treatment (p = 0.02). TDI showed decreased E' velocity (p < 0.001) and E'/A' ratio (p < 0.001) at lateral tricuspid annulus segment in TG-I, and these findings continued in TG-II and -III. In addition, S' velocity decreased in TG-I, -II, and -III at lateral mitral annulus (10.5 ± 2.6 cm/s, p < 0.05; 9.9 ± 2.2 cm/s, p < 0.001; and 10.1 ± 2.3 cm/s, p < 0.01, respectively). However, decrease in left-ventricular ejection fraction was statistically significant in TG-II and -III (p < 0.001). Although myocardial performance index was significantly increased in all treatment groups in both segments, it was primarily due to significant increases in isovolumic relaxation time at the lateral tricuspid annulus and isovolumic contraction time at the lateral mitral annulus. Abnormalities in diastolic function in right ventricle and systolic function in the left ventricle were observed even with a cumulative anthracycline dose <120 mg/m(2) by TDI. In addition, anthracycline treatment led to an increase in QTc dispersion.

Evaluation of traditional and novel measures of cardiac function to detect anthracycline-induced cardiotoxicity in survivors of childhood cancer

PURPOSE

Cardiovascular disease is the leading noncancer cause of death among survivors of childhood cancer. Ejection fraction (EF) and fractional shortening (FS) are common echocardiographic measures of cardiac function, but newer imaging modalities may provide additional information about preclinical disease. This study aimed to evaluate these modalities in detection of anthracycline-induced cardiac toxicity.

METHODS

We compared mean radial displacement, EF, and FS among 17 adult survivors of childhood cancer exposed to ≥ 300 mg/m(2) of anthracyclines to 17 age- and sex-matched healthy controls. Survivors with a history of cardiac-directed radiation, diabetes, or heart disease were excluded.

RESULTS

Survivors (35% male), mostly with history of treatment for a solid tumor, had a median age at diagnosis of 15 years (1-20) and 27 years (18-50) at evaluation. Median anthracycline exposure was 440 (range 300-645) mg/m(2). FS (35.5 vs. 39.6%, p < 0.01) and radial displacement (5.6 vs. 6.7 mm, p = 0.02) were significantly lower in survivors compared to controls, respectively. Although the mean EF was lower in survivors versus controls (55.4 vs. 59.7%), it was not statistically significant (p = 0.057). All echocardiographic measures were inversely associated with anthracycline dose, though radial displacement was no longer significantly correlated with anthracycline dose after controlling for survival time (p = 0.07), while EF remained correlated (p = 0.003).

IMPLICATIONS FOR CANCER SURVIVORS

Radial displacement, EF, and FS are lower in childhood cancer survivors compared to controls. In this study, radial displacement added no new information beyond the traditional measures, but clinical utility remains undetermined and requires further longitudinal study.

Use of cardiac markers for monitoring of doxorubixin-induced cardiotoxicity in children with cancer

The aim of this study was to evaluate N-terminal probrain natriuretic peptides (NT-pro-BNP), cardiac troponin T, and creatinine kinase, MB isoenzyme (CK-MB) in the determination of subclinical left ventricular (LV) dysfunction by echocardiography in patients treated with doxorubicin. We performed a cross-sectional case study of systolic, diastolic function and tissue Doppler imaging by echocardiography in children with cancer who received a certain cumulative dose of doxorubicin. Blood levels for NT-pro-BNP, cardiac troponin T, and CK-MB were analyzed within 6 hours of the cardiac study. Of 30 patients, 5 (16.7%) had LV dysfunction with an abnormally high NT-pro-BNP level of 363 ± 78 pg/mL, whereas patients with normal LV function had an NT-pro-BNP level of 148 ± 173 pg/mL (P = 0.012). The NT-pro-BNP level not only inversely correlated with fractional shortening (r = -0.43, P = 0.017) and ejection fraction (r = - 0.45, P = 0.013) but also correlated with mitral deceleration time ( r = 0.41, P = 0.021) and a cumulative dose of doxorubicin (r = 0.44, P = 0.014). For tissue Doppler imaging, NT-pro-BNP correlated with a peak systolic velocity at the myocardial segment (Sm) (r = -0.40, P = 0.027). NT-pro-BNP is a sensitive test and has a moderate relationship with the LV systolic and diastolic function, thus making it a useful cardiac marker for the monitoring of early anthracycline cardiotoxicity.

Long-term heart function after adjuvant epirubicin chemotherapy for breast cancer

BACKGROUND

Newer studies raise concern that adjuvant anthracycline treatment for breast cancer (BC) causes long-term heart damage. We aimed to examine whether heart failure or impairment could be demonstrated several years after low-dose epirubicin-based adjuvant treatment.

MATERIAL AND METHODS

The study-population was a historical cohort comprising 980 women who were randomized to receive one of two adjuvant regimens for treatment for BC: 7-9 cycles of cyclophosphamide-epirubicin-5-fluorouracil [CEF (600 + 60 + 600 mg/m(2))] or cyclophosphamide-methotrexate-5- fluorouracil [CMF (600 + 40 + 600 mg/m(2))]. We collected information in national registries of death and diagnoses and a sample of 77 survivors was examined with tissue-Doppler imaging (TDI), echocardiography, radionuclide ventriculography and N-terminal-pro-B-type-natriuretic peptide (NT-proBNP), an established marker for heart failure.

RESULTS AND CONCLUSION

Median follow-up was 12 years (39 days-20 years). Fifty-one percent had died. Incidence of CHF was 2.6/1000/year and equal in the treatment groups. In the sample, individuals who had received CEF showed no cardiac impairment when compared to individuals who received CMF. NT-proBNP-levels were within normal limits but higher in the CEF-group than in the CMF-group (confidence limits 105-226%, p = 0.03). Results of our study seem reassuring regarding the long-term risk of cardiotoxicity following low-dose adjuvant epirubicin treatment. However, larger, longitudinal studies are needed to establish the clinical implications.

Cardiovascular programming in children born small for gestational age and relationship with prenatal signs of severity

OBJECTIVE

The objective of the study was to evaluate cardiovascular function in children who were small-for-gestational-age (SGA) fetuses.

STUDY DESIGN

This was a prospective study including 100 controls and 50 children diagnosed in utero as SGA after 34 weeks subdivided into the following categories: SGA and intrauterine growth restriction (IUGR) according to the absence or presence, respectively, of weight centile less than 3 or abnormal cerebroplacental Doppler. Postnatal cardiovascular outcome was evaluated at 3-6 years of age by echocardiography, blood pressure, and carotid ultrasound.

RESULTS

Both SGA and IUGR presented in childhood more globular hearts, reduced longitudinal motion, and impaired relaxation with an increase in radial function. Both groups showed increased blood pressure and carotid intima-media thickness. There was a linear tendency to worse cardiovascular results in IUGR as compared with SGA.

CONCLUSION

Fetal cardiovascular programming occurs in SGA, regardless of Doppler and weight centile. These findings challenge the concept of constitutionally small and warrant further investigation to identify predictors of cardiovascular outcome in SGA.

Non-invasive imaging and monitoring cardiotoxicity of cancer therapeutic drugs

Cardiotoxicity due to administration of cancer therapeutic agents such as anthracyclines and herceptin are well described. Established guidelines to screen for chemotherapy-related cardiotoxicity (CRC) are primarily based on serial assessment of left ventricular (LV) ejection fraction (EF). However, other parameters such as LV volume, diastolic function, and strain may also be useful in screening for cardiotoxicity. More recent advances in molecular imaging of apoptosis and tissue characterization by cardiac MRI are techniques which might allow early detection of patients at high risk for developing cardiotoxicity prior to a drop in EF. This comprehensive multi-modality review will discuss both the current established imaging techniques as well as the emerging technologies which may revolutionize the future of screening and evaluation for CRC.

Left ventricular twisting and untwisting motion in childhood cancer survivors

BACKGROUND

Anthracycline has been shown to degrade titin that plays a role in myocardial twisting and untwisting. This study aimed to test the hypothesis that left ventricular (LV) twisting and untwisting motion may be altered in children after anthracycline therapy.

METHODS

Thirty-six childhood leukemia survivors aged 15.6 ± 5.5 years and 20 healthy controls aged 16.8 ± 7.7 years (P = 0.54) were studied. LV twisting and untwisting motion was determined using speckle tracking imaging, whereas LV ejection fraction and systolic and diastolic mitral annular velocities were determined respectively by three-dimensional and tissue-Doppler echocardiography.

RESULTS

Compared with controls, patients had significantly lower LV ejection fraction (P = 0.01) but similar systolic and diastolic mitral annular velocities (all P > 0.05). Their peak LV torsion (P = 0.003), systolic twisting velocity (P < 0.001), and diastolic untwisting velocity (P = 0.04) were significantly lower than controls, which could be attributable to their reduced apical rotation (P = 0.03) and apical untwisting rate (P = 0.002). For the whole cohort, LV systolic torsion and twisting velocity correlated significantly with apical untwisting rate (P < 0.001) and LV diastolic untwisting velocity (P < 0.001). In patients, none of the twisting or untwisting parameters were found to correlate with cumulative anthracycline dose (all P > 0.05). Twenty-eight (78%) patients had LV ejection fractions ≥50%. Although their systolic and diastolic mitral annular velocities were similar to those of controls, their peak LV torsion (P = 0.005), apical untwisting rate (P = 0.01), and LV systolic twisting velocity (P = 0.001) remained significantly lower.

CONCLUSION

Impairment of LV twisting and untwisting motion is evident in children after anthracycline therapy, even in those with "normal" LV ejection fractions.

Cardiovascular effects of systemic cancer treatment

Many methods of systemic anticancer treatment have detrimental effects on the cardiovascular system, thus limiting the possibility of further therapy, worsening patients' quality of life and increasing mortality. The best recognized and most clinically relevant is the cardiotoxicity of anthracyclines. Other cytotoxic drugs associated with significant risk of cardiovascular complications include alkylating agents, 5-fluorouracil and paclitaxel. Cardiovascular adverse effects are also associated with the use of targeted therapies, such as trastuzumab, bevacizumab and tyrosine kinase inhibitors, and some of the drugs used in the treatment of hematological malignancies, such as all-trans-retinoic acid and arsenic trioxide. The most serious cardiac complication of anticancer therapy is congestive heart failure, associated predominantly with the use of anthracyclines, trastuzumab and high-dose cyclophosphamide. Myocardial ischemia is mainly caused by antimetabolite and interferon alpha treatment. Other adverse effects may include hypotension, hypertension, arrhythmias and conduction disorders, edema, pericarditis and thrombo-embolic complications. The aim of this review is to summarize and critically analyze the available evidence on the cardiovascular toxicity of systemic anticancer therapies, with particular attention to the recently recognized adverse effects of targeted therapies.

Fetal growth restriction results in remodeled and less efficient hearts in children

BACKGROUND

Fetal growth restriction (FGR) affects 5% to 10% of newborns and is associated with increased cardiovascular mortality in adulthood. The most commonly accepted hypothesis is that fetal metabolic programming leads secondarily to diseases associated with cardiovascular disease, such as obesity, diabetes mellitus, and hypertension. Our main objective was to evaluate the alternative hypothesis that FGR induces primary cardiac changes that persist into childhood.

METHODS AND RESULTS

Within a cohort of fetuses with growth restriction identified in fetal life and followed up into childhood, we randomly selected 80 subjects with FGR and compared them with 120 normally grown fetuses, matched for gender, birth date, and gestational age at birth. Cardiovascular assessment was performed in childhood (mean age of 5 years). Compared with control subjects, children with FGR had a different cardiac shape, with increased transversal diameters and more globular cardiac ventricles. Although left ejection fraction was similar among the study groups, stroke volume was reduced significantly, which was compensated for by an increased heart rate to maintain output in severe FGR. This was associated with subclinical longitudinal systolic dysfunction (decreased myocardial peak velocities) and diastolic changes (increased E/E' ratio and E deceleration time). Children with FGR also had higher blood pressure and increased intima-media thickness. For all parameters evaluated, there was a linear increase with the severity of growth restriction.

CONCLUSIONS

These findings suggest that FGR induces primary cardiac and vascular changes that could explain the increased predisposition to cardiovascular disease in adult life. If these results are confirmed, the impact of strategies with beneficial effects on cardiac remodeling should be explored in children with FGR.

Screening for cardiomyopathy in muscular dystrophy with tissue doppler imaging

OBJECTIVE

To study role of Tissue Doppler imaging (TDI) in identification of cardiomyopathy before development of ventricular dysfunction.

METHODS

Twenty-five patients with Duchenne's (DMD) and 10 with Becker's (BMD) muscular dystrophy along with 20 controls were evaluated using TDI.

RESULTS

Pulse Tissue Doppler signals of the lateral left ventricle wall (lateral mitral annulus) revealed reduced systolic velocities in the DMD patients (mean +/- SD: 7.8 +/- 1.1 cm/sec vs. 8.6 +/- 1.1 cm/sec in controls) in patients of DMD. 60% of the non ambulatory DMD (ejection fraction 45+/-9%) patients had mild LV dysfunction and reduced systolic velocities (6.96 +/- 1.7 cm/sec, p<0.05 vs controls). The ambulatory DMD patients also had reduced systolic velocities (7.8 +/- 1.1 cm/sec) though ejection fraction was normal. Reduced tissue Doppler systolic velocities in the ambulatory DMD patients with normal conventional echocardiography would suggest that perhaps some of these patients (20% had velocities less than Mean - 2 SD of controls) have early myocardial dysfunction (picked up only as abnormal myocardial velocities).

CONCLUSIONS

TDI picked up systolic dysfunction of the lateral wall in DMD even when overall LV function was normal conventional echocardiography. Tissue Doppler imaging is a useful technique to pick up early ventricular dysfunction and should be evaluated in larger studies and also with other techniques like magnetic resonance imaging.