Cardiac function, perfusion, and morbidity in irradiated long-term survivors of Hodgkin's disease

Coronary artery disease surveillance among childhood, adolescent and young adult cancer survivors: A systematic review and recommendations from the International Late Effects of Childhood Cancer Guideline Harmonization Group

BACKGROUND

Coronary artery disease (CAD) is a concerning late outcome for cancer survivors. However, uniform surveillance guidelines are lacking.

AIM

To harmonise international recommendations for CAD surveillance for survivors of childhood, adolescent and young adult (CAYA) cancers.

METHODS

A systematic literature review was performed and evidence graded using the Grading of Recommendations, Assessment, Development and Evaluation criteria. Eligibility included English language studies, a minimum of 20 off-therapy cancer survivors assessed for CAD, and 75% diagnosed prior to age 35 years. All study designs were included, and a multidisciplinary guideline panel formulated and graded recommendations.

RESULTS

32 of 522 identified articles met eligibility criteria. The prevalence of CAD ranged from 0 to 72% and was significantly increased compared to control populations. The risk of CAD was increased among survivors who received radiotherapy exposing the heart, especially at doses ≥15 Gy (moderate-quality evidence). The guideline panel agreed that healthcare providers and CAYA cancer survivors treated with radiotherapy exposing the heart should be counselled about the increased risk for premature CAD. While the evidence is insufficient to support primary screening, monitoring and early management of modifiable cardiovascular risk factors are recommended. Initiation and frequency of surveillance should be based on the intensity of treatment exposures, family history, and presence of co-morbidities but at least by age 40 years and at a minimum of every 5 years. All were strong recommendations.

CONCLUSION

These systematically assessed and harmonised recommendations for CAD surveillance will inform care and guide research concerning this critical outcome for CAYA cancer survivors.

Vascular toxic effects of cancer therapies

Cancer therapies can lead to a broad spectrum of cardiovascular complications. Among these, cardiotoxicities remain of prime concern, but vascular toxicities have emerged as the second most common group. The range of cancer therapies with a vascular toxicity profile and the clinical spectrum of vascular toxic effects are quite broad. Historically, venous thromboembolism has received the greatest attention but, over the past decade, the arterial toxic effects, which can present as acute vasospasm, acute thrombosis and accelerated atherosclerosis, of cancer therapies have gained greater recognition. This Review focuses on these types of cancer therapy-related arterial toxicity, including their mechanisms, and provides an update on venous thromboembolism and pulmonary hypertension associated with cancer therapies. Recommendations for the screening, treatment and prevention of vascular toxic effects of cancer therapies are outlined in the context of available evidence and society guidelines and consensus statements. The shift towards greater awareness of the vascular toxic effects of cancer therapies has further unveiled the urgent needs in this area in terms of defining best clinical practices. Well-designed and well-conducted clinical studies and registries are needed to more precisely define the incidence rates, risk factors, primary and secondary modes of prevention, and best treatment modalities for vascular toxicities related to cancer therapies. These efforts should be complemented by preclinical studies to outline the pathophysiological concepts that can be translated into the clinic and to identify drugs with vascular toxicity potential even before their widespread clinical use.

Potential Clinical Implications of miR-1 and miR-21 in Heart Disease and Cardioprotection

The interest in non-coding RNAs, which started more than a decade ago, has still not weakened. A wealth of experimental and clinical studies has suggested the potential of non-coding RNAs, especially the short-sized microRNAs (miRs), to be used as the new generation of therapeutic targets and biomarkers of cardiovascular disease, an ever-growing public health issue in the modern world. Among the hundreds of miRs characterized so far, microRNA-1 (miR-1) and microRNA-21 (miR-21) have received some attention and have been associated with cardiac injury and cardioprotection. In this review article, we summarize the current knowledge of the function of these two miRs in the heart, their association with cardiac injury, and their potential cardioprotective roles and biomarker value. While this field has already been extensively studied, much remains to be done before research findings can be translated into clinical application for patient’s benefit.

Radiation-Associated Cardiac Disease: From Molecular Mechanisms to Clinical Management

PURPOSE OF REVIEW

Radiation-associated cardiac disease (RACD) is an increasingly recognized latent manifestation of chest and mediastinal radiation therapy. The delayed presentation reflects increased survival rates from malignancies successfully treated decades previously. However, individuals are now presenting with multiple coexistent manifestations of RACD and pulmonary disease as a consequence of high-dose radiation administered prior to the routine institution of modern dose-modulating regimens. Increased awareness of RACD is critical for implementation of appropriate screening algorithms and for specific management strategies involving the timing and strategies of intervention in these patients.

RECENT FINDINGS

Recent advances in multimodality cardiac imaging have demonstrated pathognomonic findings of RACD, which can predict outcomes including mortality. Accurate diagnosis of these typically concurrent manifestations is critical and should prompt referral to a center experienced in managing RACD as surgical risk is significantly increased for this patient cohort, particularly for those undergoing redo operation. The latent effect of RACD and its unique combination of manifestations means that these patients will increasingly present with challenging management issues, resulting in increased rates of morbidity and mortality. Timing of treatment intervention must be carefully considered, although percutaneous options may provide alternative future strategies for this higher risk cohort.

Multimodality Imaging in Restrictive Cardiomyopathies: An EACVI expert consensus document In collaboration with the "Working Group on myocardial and pericardial diseases" of the European Society of Cardiology Endorsed by The Indian Academy of Echocardiography

Restrictive cardiomyopathies (RCMs) are a diverse group of myocardial diseases with a wide range of aetiologies, including familial, genetic and acquired diseases and ranging from very rare to relatively frequent cardiac disorders. In all these diseases, imaging techniques play a central role. Advanced imaging techniques provide important novel data on the diagnostic and prognostic assessment of RCMs. This EACVI consensus document provides comprehensive information for the appropriateness of all non-invasive imaging techniques for the diagnosis, prognostic evaluation, and management of patients with RCM.

Radiation Therapy Is Associated With an Increased Incidence of Cardiac Events in Patients with Small Cell Lung Cancer

PURPOSE

Cardiac radiation dose was a predictor of inferior overall survival in the Radiation Therapy Oncology Group 0617 non-small cell lung cancer trial. We examined the association between radiation therapy (RT) and cardiac events (CE) for patients with small cell lung cancer (SCLC).

METHODS AND MATERIALS

The US population-based Surveillance, Epidemiology, and End Results Program and Medicare claims databases were queried for rates of CE among patients with SCLC treated with chemotherapy (CTX) ± RT. Propensity score matching (PSM) and multivariate analysis were conducted. Patients were matched for actual/theoretical RT start date (to prevent immortal time bias) and then full PSM balanced clinical characteristics. Cumulative incidence function curves were generated.

RESULTS

From 2000 to 2011, 7060 patients were included: 2892 limited-stage SCLC (LS-SCLC) and 4168 extensive-stage SCLC. Grouping LS-SCLC and extensive-stage SCLC together, the incidence of CE for the CTX + RT and CTX-only groups was 44.1% versus 39% at 60 months (P = .008). After PSM (5286 patients), the incidence of CE for the CTX + RT and CTX-only groups was 43% versus 38.6% at 60 months (P = .033). Analysis of only LS-SCLC (2016 patients) demonstrated that the incidence of CE for CTX + RT versus CTX-only groups was 50.3% versus 42% at 60 months (P = .0231). Multivariate analysis again demonstrated an association between CE and RT (hazard ratio 1.20; 95% confidence interval 1.06-1.37; P = .005). After PSM (1614 patients), the incidence of CE for CTX + RT versus CTX-only groups was 51.7% versus 41.6% at 60 months (P = .0042).

CONCLUSIONS

Patients with SCLC are at significant risk of developing CE posttreatment; RT is associated with an absolute increase in the rate of CE at 5 years of approximately 5% for all patients with SCLC and up to 10% for patients with LS-SCLC. Cardiac risk management and cardiac-sparing RT techniques should be further evaluated for patients with SCLC.

Effects of low-dose rate γ-irradiation combined with simulated microgravity on markers of oxidative stress, DNA methylation potential, and remodeling in the mouse heart

Purpose

Space travel is associated with an exposure to low-dose rate ionizing radiation and the microgravity environment, both of which may lead to impairments in cardiac function. We used a mouse model to determine short- and long-term cardiac effects to simulated microgravity (hindlimb unloading; HU), continuous low-dose rate γ-irradiation, or a combination of HU and low-dose rate γ-irradiation.

Methods

Cardiac tissue was obtained from female, C57BL/6J mice 7 days, 1 month, 4 months, and 9 months following the completion of a 21 day exposure to HU or a 21 day exposure to low-dose rate γ-irradiation (average dose rate of 0.01 cGy/h to a total of 0.04 Gy), or a 21 day simultaneous exposure to HU and low-dose rate γ-irradiation. Immunoblot analysis, rt-PCR, high-performance liquid chromatography, and histology were used to assess inflammatory cell infiltration, cardiac remodeling, oxidative stress, and the methylation potential of cardiac tissue in 3 to 6 animals per group.

Results

The combination of HU and γ-irradiation demonstrated the strongest increase in reduced to oxidized glutathione ratios 7 days and 1 month after treatment, but a difference was no longer apparent after 9 months. On the other hand, no significant changes in 4-hydroxynonenal adducts was seen in any of the groups, at the measured endpoints. While manganese superoxide dismutase protein levels decreased 9 months after low-dose γ-radiation, no changes were observed in expression of catalase or Nrf2, a transcription factor that determines the expression of several antioxidant enzymes, at the measured endpoints. Inflammatory marker, CD-2 protein content was significantly decreased in all groups 4 months after treatment. No significant differences were observed in α-smooth muscle cell actin protein content, collagen type III protein content or % total collagen.

Conclusions

This study has provided the first and relatively broad analysis of small molecule and protein markers of oxidative stress, T-lymphocyte infiltration, and cardiac remodeling in response to HU with simultaneous exposure to low-dose rate γ-radiation. Results from the late observation time points suggest that the hearts had mostly recovered from these two experimental conditions. However, further research is needed with larger numbers of animals for a more robust statistical power to fully characterize the early and late effects of simulated microgravity combined with exposure to low-dose rate ionizing radiation on the heart.

Implication of microRNAs in the development and potential treatment of radiation-induced heart disease

Radiotherapy is the most commonly used methodology to treat oncological disease, one of the most widespread causes of death worldwide. Oncological patients cured by radiotherapy applied to the mediastinal area have been shown to suffer from cardiovascular disease. The increase in the prevalence of radiation-induced heart disease has emphasized the need to seek new therapeutic targets to mitigate the negative impact of radiation on the heart. In this regard, microRNAs (miRNAs) have received considerable interest. miRNAs regulate post-transcriptional gene expression by their ability to target various mRNA sequences because of their imperfect pairing with mRNAs. It has been recognized that miRNAs modulate a diverse spectrum of cardiac functions with developmental, pathophysiological, and clinical implications. This makes them promising potential targets for diagnosis and treatment. This review summarizes the recent findings about the possible involvement of miRNAs in radiation-induced heart disease and their potential use as diagnostic or treatment targets in this respect.

Long-term cardiovascular health in adult cancer survivors

The number of cancer survivors has tremendously increased over the past decades as a result of aging of the population and improvements in early cancer detection and treatment. Ongoing successes in cancer treatment are expected to result in a further increase in the number of long-term survivors. However, cancer treatment can have detrimental cardiovascular side-effects that impact morbidity and mortality, reducing quality of life in cancer survivors. The spectrum of radiotherapy- and chemotherapy-induced cardiovascular disease is broad, varying from subclinical valvular dysfunction to overt congestive heart failure, and such effects may not be apparent for more than twenty years after the initial cancer treatment. Awareness of these long-term side-effects is of crucial value in the management of these patients, in order to reduce the impact of cardiovascular morbidity and mortality. This review provides a comprehensive overview of the long-term cardiovascular complications of cancer treatments (radiotherapy and chemotherapy) in adult cancer survivors.

Cumulative burden of cardiovascular morbidity in paediatric, adolescent, and young adult survivors of Hodgkin's lymphoma: an analysis from the St Jude Lifetime Cohort Study

BACKGROUND

The magnitude of cardiovascular morbidity in paediatric, adolescent, and young adult survivors of Hodgkin's lymphoma is not known. Using medically ascertained data, we applied the cumulative burden metric to compare chronic cardiovascular health conditions in survivors of Hodgkin's lymphoma and general population controls.

METHODS

For this study, participant data were obtained from two ongoing cohort studies at St Jude Children's Research Hospital: the St Jude Lifetime Cohort Study (SJLIFE) and the St Jude Long-term Follow-up Study (SJLTFU). SJLIFE is a cohort study initiated on April 27, 2007, to enable longitudinal clinical evaluation of health outcomes of survivors of childhood cancer treated or followed at St Jude Children's Research Hospital, and SJLTFU is an administrative system-based study initiated in 2000 to collect outcome and late toxicity data for all patients treated at the hospital for childhood cancer. The patient cohort for our study was defined as patients treated at St Jude Children's Research Hospital who reached 18 years of age and were at least 10 years post-diagnosis of pathologically confirmed primary Hodgkin's lymphoma. Outcomes in the Hodgkin's lymphoma survivors were compared with a sample of SJLIFE community control participants, aged 18 years or older at the time of assessment, frequency-matched based on strata defined by 5-year age blocks within each sex, who were selected irrespective of previous medical history. All SJLIFE participants underwent assessment for 22 chronic cardiovascular health conditions. Direct assessments, combined with retrospective clinical reviews, were used to assign severity to conditions using a modified Common Terminology Criteria of Adverse Events (CTCAE) version 4.03 grading schema. Occurrences and CTCAE grades of the conditions for eligible non-SJLIFE participants were accounted for by multiple imputation. The mean cumulative count (treating death as a competing risk) was used to estimate cumulative burden.

FINDINGS

Of 670 survivors treated at St Jude Children's Research Hospital, who survived 10 years or longer and reached age 18 years, 348 were clinically assessed in the St Jude Lifetime Cohort Study (SJLIFE); 322 eligible participants did not participate in SJLIFE. Age and sex frequency-matched SJLIFE community controls (n=272) were used for comparison. At age 50 years, the cumulative incidence of survivors experiencing at least one grade 3-5 cardiovascular condition was 45·5% (95% CI 36·6-54·3), compared with 15·7% (7·0-24·4) in community controls. The survivor cohort at age 50 experienced a cumulative burden of 430·6 (95% CI 380·7-480·6) grade 1-5 and 100·8 (77·3-124·3) grade 3-5 cardiovascular conditions per 100 survivors; these numbers were appreciably higher than those in the control cohort (227·4 [192·7-267·5] grade 1-5 conditions and 17·0 [8·4-27·5] grade 3-5 conditions per 100 individuals). Myocardial infarction and structural heart defects were the major contributors to the excess grade 3-5 cumulative burden in survivors. High cardiac radiation dose (≥35 Gy) was associated with an increased proportion of grade 3-5 cardiovascular burden, whereas increased anthracyline dose was not.

INTERPRETATION

The true effect of cardiovascular morbidity in paediatric, adolescent, and young adult survivors of Hodgkin's lymphoma is reflected in the cumulative burden. Survivors aged 50 years will experience more than two times the number of chronic cardiovascular health conditions and nearly five times the number of more severe (grade 3-5) cardiovascular conditions compared with community controls and, on average, have one severe, life-threatening, or fatal cardiovascular condition. The cumulative burden metric provides a more comprehensive approach for assessing overall morbidity compared with currently used cumulative incidence based analytic methodologies, and will assist clinical researchers when designing future trials and refining general practice screening guidelines.

FUNDING

US National Cancer Institute, St Baldrick's Foundation, and American Lebanese Syrian Associated Charities.

Mediastinal irradiation in a patient affected by lung carcinoma after heart transplantation: Helical tomotherapy versus three dimensional conformal radiotherapy

Patients who have undergone solid organ transplants are known to have an increased risk of neoplasia compared with the general population. We report our experience using mediastinal irradiation with helical tomotherapy versus three‐dimensional conformal radiation therapy to treat a patient with lung carcinoma 15 years after heart transplantation. Our dosimetric evaluation showed no particular difference between the techniques, with the exception of some organs. Mediastinal irradiation after heart transplantation is feasible and should be considered after evaluation of the risk. Conformal radiotherapy or intensity‐modulated radiotherapy appears to be the appropriate treatment in heart‐transplanted oncologic patients.

Association between radiation dose to the heart and myocardial fatty acid metabolic impairment due to chemoradiation-therapy: Prospective study using I-123 BMIPP SPECT/CT

PURPOSE

To investigate long term changes in myocardial fatty acid metabolic impairment caused by chemoradiation-therapy (CRT).

MATERIALS AND METHODS

We investigated 12 esophageal cancer patients who underwent SPECT/CT using I-123-labeled fatty acid analog (BMIPP) at pre-CRT, pre-boost irradiation, 3-month post-CRT, and 1-year post-CRT. The myocardial uptake was measured using the defect score and the total percentage of uptake (%uptake), which were defined as the sum of the visual scores and that of %uptake in each of 17 segments in the left ventricle (LV), respectively. The correlations between radiation dose to the heart (mean dose, V20, V40, and V60 of the LV and the whole heart (WH)) and the change of myocardial BMIPP uptake from pre-CRT (Δmyocardial BMIPP uptake) were assessed.

RESULTS

At pre-boost, Δmyocardial BMIPP uptake was significantly correlated with LV-V40 and WH-V60. At 3-month post-CRT, Δmyocardial BMIPP uptake was significantly correlated with LV-V40, WH-V40, and WH-V60. However, there were no statistically significant correlations at 1-year post-CRT. Neither mean dose nor V20 of the LV/WH was significantly correlated with Δmyocardial BMIPP uptake at any time.

CONCLUSIONS

In the long term after CRT, myocardial metabolism might be affected by factors other than the radiation dose to the heart.

Radiation Effects in the Mediastinum and Surroundings: Imaging Findings and Complications

Radiotherapy is one of the cornerstones for treatment of patients with cancer. Although advances in radiotherapy technology have considerably improved radiation delivery, potential adverse effects are still common. Postradiation changes to the mediastinum can include different structures such as the heart, great vessels, and esophagus. The purpose of the article was to illustrate the expected variety of changes to the mediastinum and adjacent lung resulting from external beam radiotherapy and radiotherapy-induced complications to the mediastinum and to discuss different radiotherapy delivery techniques.

Long-term cardiac abnormalities after cranial radiotherapy in childhood cancer survivors

BACKGROUND

Cardiac morbidity is an important late effect in long-term childhood cancer survivors (CCS) treated with cardiotoxic agents or radiotherapy (RT) on the chest. However, there is limited data on the long-term cardiac sequelae in CCS who only received cranial RT. We hypothesized that cranial RT might negatively influence cardiac structure and function.

METHODS AND RESULTS

We studied 13 CCS [mean age 30.8 (18.1-39.3) years, 7 males] who received RT only on the head for a cranial tumor and 36 age- and sex-matched healthy sibling controls. Echocardiographic follow-up was performed at median 21.7 (12.6-30.8) years after diagnosis. CCS had lower indexed diastolic LV volumes [56.0 (31.4-68.3) vs. 60.5 (41.9-94.3) mL/m(2), p = 0.024]. CCS also had reduced LV systolic and diastolic function, reflected by lower systolic LV myocardial velocities (5.3 ± 0.9 vs. 7.1 ± 1.7 cm/s, p = 0.001) and longitudinal deformation (- 17.3 ± 3.1 vs. - 20.7 ± 2.0%, p < 0.001), as well as lower diastolic LV myocardial velocities (- 10.7 ± 1.7 vs. - 12.2 ± 1.5 cm/s, p = 0.006) and deformation speed (1.1 ± 0.3 vs. 1.5 ± 0.2 1/s, p = 0.005). Additionally, in CCS insulin-like growth factor levels [15.4 (9.2-34.6) vs. 24.4 (14.8-55.5) nmol/L, p = 0.007] were lower.

CONCLUSION

Cranial RT in CCS is associated with smaller cardiac volumes and reduced systolic and diastolic LV function. This off target effect of RT might be related to lower insulin-like growth factor levels.

[Postoperative radiotherapy of breast cancer and cardiotoxicity]

Cardiac complications may present a particular problem following radiation treatment applied to the mediastinum and thoracic wall (and especially to the left breast). Exposure of the heart during radiotherapy increases the risk of ischemic heart disease occurring generally years after the treatment. The incidence of radiation cardiotoxicity depends on various factors related to oncological therapies and the patient (details of radiotherapy, age, gender, comorbidities, smoking habits, etc.). Until recently the majority of clinical studies reported increased cardiac morbidity in patients receiving radiation treatment of the chest wall and the breast. Due to modern methods, however, postoperative chest wall and left breast irradiation is much safer today than previously. In order to avoid cardiotoxicity, adherence to clinical practice guidelines for chemo- and targeted therapy of breast cancer, use of the most advanced irradiation procedures, regular monitoring of patients, and close cooperation between cardiologists and oncologists are all recommended.

Radiation-induced heart disease: an under-recognized entity?

OPINION STATEMENT

Radiation-induced heart disease (RIHD) represents a spectrum of cardiovascular disease in patients who have undergone mediastinal, thoracic, or breast radiotherapy (RT). RIHD may involve any cardiac structure and is a major cause of morbidity and mortality in cancer survivors. While large cohort studies have demonstrated that symptomatic RIHD is a common late finding in this population, the incidence of asymptomatic disease is likely to be even higher. Long-term follow-up with regular screening for RIHD plays an important role in the management of cancer survivors who have undergone RT. Aggressive modification of traditional cardiovascular risk factors such as hypertension, dyslipidemia, and cigarette smoking is essential in patients at risk for RIHD, as these have been shown to potentiate the risks of radiation. In patients with symptomatic RIHD, medical and/or percutaneous therapies are often preferable to surgical interventions in view of the increased surgical risk associated with radiation damage to surrounding tissues. Percutaneous revascularization should generally be favored over surgical revascularization. Transcatheter valve replacements have not been widely used in this population but may offer an alternative to high-risk surgical valve procedures. Pericardiectomy is usually associated with extremely poor short-term and long-term outcomes in patients with RIHD and should be avoided in most cases. Heart transplantation is also higher risk in patients with RIHD than in patients with other etiologies of heart failure, but may be considered in young patients without other comorbidities.

Are cardiac magnetic resonance imaging and radionuclide ventriculography good options against echocardiography for evaluation of anthracycline induced chronic cardiotoxicity in childhood cancer survivors?

Anthracyclines are widely used for the treatment of solid tumors in pediatric oncology. However, their uses may be limited by progressive chronic cardiotoxicity related to the cumulative dosage. The aims of this study are to compare diagnostic techniques and prepare an algorithm for diagnosis of anthracycline induced chronic cardiotoxicity. The patients were evaluated according to age, sex, time elapsed since the last dose of anthracycline treatment, presence of cardiovascular symptoms, follow-up duration, type of anthracycline, cumulative anthracycline dose, and concomitant mediastinal radiation therapy. Late subclinical cardiotoxicity was detected by history, physical examination, electrocardiography (ECG), Holter monitor, echocardiography (ECHO), radionuclide ventriculography (MUGA), and cardiac magnetic resonance imaging (MRI). Thirty-seven male and 19 female patients with a median age of 11.2 ± 4.6 (range, 3.5-22.0) years were included in the study. Patients were grouped according to cumulative anthracycline doses. Subclinical cardiac dysfunction was detected in 20 patients by at least one of ECHO, MRI or MUGA after anthracycline chemotherapy. We revealed that other than ECHO, MRI and MUGA have high clinical importance for evaluating subclinical late cardiac complications in children treated with anthracyclines.

Expert consensus for multi-modality imaging evaluation of cardiovascular complications of radiotherapy in adults: a report from the European Association of Cardiovascular Imaging and the American Society of Echocardiography

Cardiac toxicity is one of the most concerning side effects of anti-cancer therapy. The gain in life expectancy obtained with anti-cancer therapy can be compromised by increased morbidity and mortality associated with its cardiac complications. While radiosensitivity of the heart was initially recognized only in the early 1970s, the heart is regarded in the current era as one of the most critical dose-limiting organs in radiotherapy. Several clinical studies have identified adverse clinical consequences of radiation-induced heart disease (RIHD) on the outcome of long-term cancer survivors. A comprehensive review of potential cardiac complications related to radiotherapy is warranted. An evidence-based review of several imaging approaches used to detect, evaluate, and monitor RIHD is discussed. Recommendations for the early identification and monitoring of cardiovascular complications of radiotherapy by cardiac imaging are also proposed.

Expert consensus for multi-modality imaging evaluation of cardiovascular complications of radiotherapy in adults: a report from the European Association of Cardiovascular Imaging and the American Society of Echocardiography

Cardiac toxicity is one of the most concerning side effects of anti-cancer therapy. The gain in life expectancy obtained with anti-cancer therapy can be compromised by increased morbidity and mortality associated with its cardiac complications. While radiosensitivity of the heart was initially recognized only in the early 1970s, the heart is regarded in the current era as one of the most critical dose-limiting organs in radiotherapy. Several clinical studies have identified adverse clinical consequences of radiation-induced heart disease (RIHD) on the outcome of long-term cancer survivors. A comprehensive review of potential cardiac complications related to radiotherapy is warranted. An evidence-based review of several imaging approaches used to detect, evaluate, and monitor RIHD is discussed. Recommendations for the early identification and monitoring of cardiovascular complications of radiotherapy by cardiac imaging are also proposed.

Cardiovascular complications of radiation therapy for thoracic malignancies: the role for non-invasive imaging for detection of cardiovascular disease

Radiation exposure to the thorax is associated with substantial risk for the subsequent development of cardiovascular disease. Thus, the increasing role of radiation therapy in the contemporary treatment of cancer, combined with improving survival rates of patients undergoing this therapy, contributes to a growing population at risk of cardiovascular morbidity and mortality. Associated cardiovascular injuries include pericardial disease, coronary artery disease, valvular disease, conduction disease, cardiomyopathy, and medium and large vessel vasculopathy-any of which can occur at varying intervals following irradiation. Higher radiation doses, younger age at the time of irradiation, longer intervals from the time of radiation, and coexisting cardiovascular risk factors all predispose to these injuries. The true incidence of radiation-related cardiovascular disease remains uncertain due to lack of large multicentre studies with a sufficient duration of cardiovascular follow-up. There are currently no consensus guidelines available to inform the optimal approach to cardiovascular surveillance of recipients of thoracic radiation. Therefore, we review the cardiovascular consequences of radiation therapy and focus on the potential role of non-invasive cardiovascular imaging in the assessment and management of radiation-related cardiovascular disease. In doing so, we highlight characteristics that can be used to identify individuals at risk for developing post-radiation cardiovascular disease and propose an imaging-based algorithm for their clinical surveillance.

Risk factors affecting cardiac left-ventricular hypertrophy and systolic and diastolic function in the chronic phase of allogeneic hematopoietic cell transplantation

Chronic impairment of cardiac function can be an important health risk and impair the quality of life, and may even be life-threatening for long-term survivors of allogeneic hematopoietic cell transplantation (HCT). However, risk factors for and/or the underlying mechanism of cardiac dysfunction in the chronic phase of HCT are still not fully understood. We retrospectively investigated factors affecting cardiac function and left-ventricular hypertrophy (LVH) in the chronic phase of HCT. Sixty-three recipients who survived for >1 year after receiving HCT were evaluated using echocardiography. Based on simple linear regression models, high-dose TBI-based conditioning was significantly associated with a decrease in left-ventricular ejection fraction and the early peak flow velocity/atrial peak flow velocity ratio, following HCT (coefficient=-5.550, P=0.02 and coefficient=-0.268, P=0.02, respectively). These associations remained significant with the use of multiple linear regression models. Additionally, the serum ferritin (s-ferritin) level before HCT was found to be a significant risk factor for LVH on multivariable logistic analysis (P=0.03). In conclusion, our study demonstrated that a myeloablative regimen, especially one that involved high-dose TBI, impaired cardiac function, and that a high s-ferritin level might be associated with the development of LVH in the chronic phase of HCT.

Cardiovascular Disease

Although important advances have been made in curing childhood cancer in the last several decades, long-term survivors face considerable morbidity and mortality because of late effects from their initial anticancer therapy. By 30 years after treatment, the cumulative mortality from treatment-related medical illness actually exceeds that of mortality from cancer recurrence. Cardiovascular disease, in particular, is a leading threat to the well-being of adult survivors of childhood cancers. Unfortunately, the mechanisms of these late cardiac effects are understudied and poorly understood. This article reviews cardiotoxicity associated with 2 major anticancer regimens used in treating childhood cancer patients: anthracycline treatment and radiation therapy. The known pathophysiology and clinical cardiac risk factors that further predispose these patients to late-onset cardiac events are discussed. Basic and translational research is urgently needed to clarify pathophysiologic mechanisms of late cardiac effects and to develop therapies to improve both long-term survival and quality of life of adults cured of pediatric cancers.

Radiation-induced heart disease: a clinical update

Cardiovascular diseases and cancer are the two leading causes of morbidity and mortality worldwide. Improvement in cancer therapy has led to increasing number of cancer survivors, some of whom may suffer from adverse cardiovascular effects of radiation therapy. Longterm followup is essential, as the cardiac complication may manifest years after completion of radiation therapy. In this paper, we have discussed the cardiovascular effects of radiation therapy.

Screening Hodgkin lymphoma survivors for radiotherapy induced cardiovascular disease

Long term prognosis of Hodgkin lymphoma (HL) survivors is affected by late toxicity of radiotherapy and chemotherapy. Cardiovascular complications of radiotherapy have been shown to have a great impact on the long term survival. The aim of this review is to summarize the available data on different screening modalities for cardiovascular disease and to suggest a screening program. Patients older than 45 years at HL diagnosis should be screened for coronary artery disease (CAD) starting 5 years after mediastinal radiotherapy; they are at increased risk of pre-existent atherosclerosis which can be accelerated by radiotherapy. Screening for CAD should start 10 years after radiotherapy in younger patients. The best screening modality for CAD is subject of discussion, based on the latest studies we suggest screening by Coronary artery calcium score measurements or CT-angiography. Valvular disorders should be looked for by echocardiography starting 10 years after radiotherapy. Electrocardiograms should be performed at each cardiovascular screening moment in order to detect arrhythmia's or conduction abnormalities. We suggest repeating these screening tests every 5 years or at onset of cardiovascular complaints; patients should be extensively instructed about signs and symptoms of cardiovascular disease. Furthermore traditional risk factors for cardiovascular disease should be carefully monitored and treated. We suggest determining a cardiovascular risk profile at diagnosis of HL in patients older than 45 years. In case of a high risk, treating HL without RT should be considered.

Cardiac Function in Long-Term Survivors of Childhood Lymphoma

Objectives. We studied long-term effects of therapy for childhood lymphoma on cardiac function. Design and patients. We prospectively evaluated 45 survivors of childhood lymphoma, using clinical parameters, electrocardiography and echocardiography. Further comparisons were made between lymphoma subgroups and between males and females. Results. Mean age at diagnosis was 9.1 years. Mean followup duration was 10.9 years. The NYHA functional class was I in 43 patients and II in 2 patients. A prolonged QTc interval (>0.44 msec) was found in 8 patients. Left ventricular (LV) systolic function and compliance were normal (LV shortening fraction 40 ± 5.6%; cardiac index 2.84 ± 1.13 L/min/m²; E/A wave ratio 2.5 ± 1.3; mean ± S.D.), LV mass was normal (97 ± 40 grams/m², mean ± S.D.). Mitral regurgitation was observed in 7/45 patients (16%). Asymptomatic pericardial effusions were found in 3/45 (7%) patients. Conclusions. Long-term follow-up shows that most parameters of cardiac function are normal in survivors of childhood lymphoma. This is likely due to relatively low doses of anthracyclines in modern protocol modalities. Abnormalities in mitral valve flow, QTc prolongation and in a small proportion of survivors, and functional capacity necessitate long-term cardiac follow-up of these patients.

Impaired vascular function in asymptomatic young adult survivors of Hodgkin Lymphoma following mediastinal radiation

BACKGROUND

Mediastinal radiation can accelerate atherosclerosis in Hodgkin lymphoma survivors (HLS), and early detection is optimal. Peripheral arterial tonometry (PAT), a non-invasive measure of endothelial function, is a surrogate marker of sub-clinical atherosclerosis. The objective of our study was to evaluate endothelial function in HLS and controls using PAT and to determine the influence of mediastinal radiation.

PROCEDURE

Cross-sectional evaluation was performed on 26 HLS aged 12-30 years who were a minimum of 2 years from therapy, and their healthy age and gender matched controls. Evaluation included assessment for cardiovascular risk factors and completion of the Habitual Activity Estimation Score (HAES) questionnaire to assess activity level. Endothelial Function was measured using PAT hyperemia ratios (PAT-HR).

RESULTS

HLS and controls were similar for baseline variables (mean age 23.3 +/- 5 yrs vs. 23.4 +/- 4.8 yrs, p = 0.92). HLS were on average 6.7 +/- 4.6 yrs post treatment. No differences in endothelial function or cardiovascular risk factors were observed between HLS and controls. However, impaired endothelial function, as evidenced by lower PAT-HR (1.67 +/- 0.39 vs. 2.03 +/- 0.37, p < 0.01) was seen in HLS (n = 13) who received mediastinal radiation (mean radiation dose 2,600 +/- 840 cGy) compared to controls.

CONCLUSIONS

Impaired endothelial function was preferentially observed in HLS who received mediastinal radiation, while no difference was observed between the HLS and control groups overall. This finding, assessed using a non invasive test of endothelial function, confirms that mediastinal radiation is an additional cardiovascular risk factor in this young cohort of patients. Further studies of endothelial function in this patient population are warranted.

Cardiac magnetic resonance imaging findings in 20-year survivors of mediastinal radiotherapy for Hodgkin's disease

PURPOSE

The recognition of the true prevalence of cardiac toxicity after mediastinal radiotherapy requires very long follow-up and a precise diagnostic procedure. Cardiac magnetic resonance imaging (MRI) permits excellent quantification of cardiac function and identification of localized myocardial defects and has now been applied to a group of 20-year Hodgkin's disease survivors.

METHODS AND MATERIALS

Of 143 patients treated with anterior mediastinal radiotherapy (cobalt-60, median prescribed dose 40 Gy) for Hodgkin's disease between 1978 and 1985, all 53 survivors were invited for cardiac MRI. Of those, 36 patients (68%) presented for MRI, and in 31 patients (58%) MRI could be performed 20-28 years (median, 24) after radiotherapy. The following sequences were acquired on a 1.5-T MRI: transversal T1-weighted TSE and T2-weighted half-fourier acquisition single-shot turbo-spin-echo sequences, a steady-state free precession (SSFP) cine sequence in the short heart axis and in the four-chamber view, SSFP perfusion sequences under rest and adenosine stress, and a SSFP inversion recovery sequence for late enhancement. The MRI findings were correlated with previously reconstructed doses to cardiac structures.

RESULTS

Clinical characteristics and reconstructed doses were not significantly different between survivors undergoing and not undergoing MRI. Pathologic findings were reduced left ventricular function (ejection fraction <55%) in 7 (23%) patients, hemodynamically relevant valvular dysfunction in 13 (42%), late myocardial enhancement in 9 (29%), and any perfusion deficit in 21 (68%). An association of regional pathologic changes and reconstructed dose to cardiac structures could not be established.

CONCLUSIONS

In 20-year survivors of Hodgkin's disease, cardiac MRI detects pathologic findings in approximately 70% of patients. Cardiac MRI has a potential role in cardiac imaging of Hodgkin's disease patients after mediastinal radiotherapy.

The potential of proton beam therapy in paediatric cancer

A group of Swedish oncologists and hospital physicists have estimated the number of patients in Sweden suitable for proton beam therapy. The estimations have been based on current statistics of tumour incidence, number of patients potentially eligible for radiation treatment, scientific support from clinical trials and model dose planning studies and knowledge of the dose-response relations of different tumours and normal tissues. It is estimated that in paediatric cancers, proton beams are of potential importance in 80-100 children annually in Sweden. About 20 of the patients have medulloblastoma. The main purpose is to reduce late sequelae, but these are also increased chances to avoid myelosupression during e.g. concomitant chemo-radiation and to further intensify the chemotherapy.

Challenges after curative treatment for childhood cancer and long-term follow up of survivors

Childhood cancer survivors are at increased risk of serious morbidity, premature mortality, and diminished health status. Proactive and anticipatory risk-based health care of survivors and healthy lifestyles can reduce these risks. In this article, the authors first briefly discuss four common problems of survivors: neurocognitive dysfunction, cardiovascular disease, infertility and gonadal dysfunction, and psychosocial problems. Second, the authors discuss the concept of risk-based care, promote the use of recently developed evidence-based guidelines, describe current care in the United States, Canada, and the Netherlands, and articulate a model for shared survivor care that aims to optimize life long health of survivors and improve two-way communication between the cancer center and the primary care physician.

Monitoring for cardiovascular disease in survivors of childhood cancer: report from the Cardiovascular Disease Task Force of the Children's Oncology Group

Curative therapy for childhood cancer has improved significantly in the last 2 decades such that, at present, approximately 80% of all children with cancer are likely to survive > or = 5 years after diagnosis. Prevention, early diagnosis, and treatment of long-term sequelae of therapy have become increasingly more significant as survival rates continue to improve. Cardiovascular disease is a well-recognized cause of increased late morbidity and mortality among survivors of childhood cancer. The Children's Oncology Group Late Effects Committee and Nursing Discipline and Patient Advocacy Committee have recently developed guidelines for follow-up of long-term survivors of pediatric cancer. A multidisciplinary task force critically reviewed the existing literature to evaluate the evidence for the cardiovascular screening recommended by the Children's Oncology Group guidelines. In this review we outline the clinical manifestations of late cardiovascular toxicities, suggest modalities and frequency of monitoring, and address some of the controversial and unresolved issues regarding cardiovascular disease in childhood cancer survivors.

American Society of Clinical Oncology clinical evidence review on the ongoing care of adult cancer survivors: cardiac and pulmonary late effects

PURPOSE

To review the evidence on the incidence of long-term cardiac or pulmonary toxicity secondary to chemotherapy, radiotherapy, or trastuzumab in symptomatic and asymptomatic cancer survivors.

METHODS

An American Society of Clinical Oncology Panel reviewed pertinent information from the literature through February 2006.

RESULTS

Few studies directly addressing the benefits of screening for long-term cardiac or pulmonary toxicity in asymptomatic cancer survivors who received chemotherapy, radiotherapy, or trastuzumab were identified. The reviewed literature included primarily retrospective and cross-sectional studies describing the incidence of cardiac and pulmonary late effects. Anatomic and/or functional abnormalities have been associated with use of all currently available anthracyclines and their derivatives. Trastuzumab-related cardiac dysfunction rarely causes death, and in most cases is reversible with improvement in cardiac function on drug discontinuation and/or treatment with cardiac medications. The estimated aggregate incidence of radiation-induced cardiac disease is 10% to 30% by 5 to 10 years post-treatment, although the incidence may be lower with modern techniques. Radiation pneumonitis is reported in 5% to 15% of lung cancer patients receiving definitive external-beam radiation therapy. A minority of patients may develop progressive pulmonary fibrosis; late complications include cor pulmonale and respiratory failure. Bleomycin-induced pneumonitis is an acute rather than late effect of treatment. Late pulmonary complications in bone marrow or stem cell transplantation patients who develop interstitial pneumonitis include idiopathic pneumonia syndrome and bronchiolitis obliterans.

CONCLUSION

An increased incidence of cardiac and/or pulmonary dysfunction is observed in cancer survivors. Research is needed to identify high-risk patients, and to determine the optimal screening strategies and subsequent treatment.

Active Breathing Control for Hodgkin’s Disease in Childhood and Adolescence: Feasibility, Advantages, and Limits

PURPOSE

The challenge in early Hodgkin's disease (HD) in children is to maintain good survival rates while sparing organs at risk. This study assesses the feasibility of active breathing control (ABC) in children, and compares normal tissue irradiation with and without ABC.

METHODS AND MATERIALS

Between May 2003 and June 2004, seven children with HD with mediastinal involvement, median age 15, were treated by chemotherapy and involved-field radiation therapy. A free-breathing computed tomography simulation scan and one additional scan during deep inspiration using ABC were performed. A comparison between planning treatment with clinical target volume including supraclavicular regions, mediastinum, and hila was performed, both in free breathing and using ABC.

RESULTS

For a prescription of 36 Gy, pulmonary dose-volume histograms revealed a mean reduction in lung volume irradiated at more than 20 Gy (V20) and 30 Gy (V30) of 25% and 26%, respectively, using ABC (p = 0.016). The mean volume of heart irradiated at 30 Gy or more decreased from 15% to 12% (nonsignificant). The mean dose delivered to breasts in girls was small in both situations (less than 2 Gy) and stable with or without ABC. Considering axillary irradiation, the mean dose delivered to breasts remained low (<9 Gy), without significant difference using ABC or not. The mean radiation dose delivered to thyroid was stable using ABC or not.

CONCLUSIONS

Using ABC is feasible in childhood. The use of ABC decreases normal lung tissue irradiation. Concerning heart irradiation, a minimal gain is also shown. No significant change has been demonstrated concerning breast and thyroid irradiation.

Screening for coronary artery disease after mediastinal irradiation for Hodgkin's disease

PURPOSE

Incidental cardiac irradiation during treatment of thoracic neoplasms has increased risks for subsequent acute myocardial infarction or sudden cardiac death. Identifying patients who have a high risk for a coronary event may decrease morbidity and mortality. The objective of this study was to evaluate whether stress imaging can identify severe, unsuspected coronary stenoses in patients who had prior mediastinal irradiation for Hodgkin's disease.

PATIENTS AND METHODS

We enrolled 294 outpatients observed at a tertiary care cancer treatment center after mediastinal irradiation doses 35 Gy for Hodgkin's disease who had no known ischemic cardiac disease. Patients underwent stress echocardiography and radionuclide perfusion imaging at one stress session. Coronary angiography was performed at the discretion of the physician.

RESULTS

Among the 294 participants, 63 (21.4%) had abnormal ventricular images at rest, suggesting prior myocardial injury. During stress testing, 42 patients (14%) developed perfusion defects (n = 26), impaired wall motion (n = 8), or both abnormalities (n = 8). Coronary angiography showed stenosis 50% in 22 patients (55%), less than 50% in nine patients (22.5%), and no stenosis in nine patients (22.5%). Screening led to bypass graft surgery in seven patients. Twenty-three patients developed coronary events during a median of 6.5 years of follow-up, with 10 acute myocardial infarctions (two fatal).

CONCLUSION

Stress-induced signs of ischemia and significant coronary artery disease are highly prevalent after mediastinal irradiation in young patients. Stress testing identifies asymptomatic individuals at high risk for acute myocardial infarction or sudden cardiac death.

Radiation dose and long term risk of cardiac pathology following radiotherapy and anthracyclin for a childhood cancer

PURPOSE

To determine the cardiac status in children 15 years (yrs) or more after a solid tumour treatment.

PATIENTS AND METHODS

Of the 447 patients, 229 were fully studied and 218 were not. The following cardiac evaluation was proposed to all the 447 consecutive patients: (1) cardiac Doppler US by one of two expert cardiologists; (2) cardiac rhythm and conduction abnormalities including 24-h holter ECG; (3) (131)I-mIBG myocardial scintigraphy; (4) serum brain natriuretic peptide levels at rest; (5) an exercise test with VO(2)max measurement. The radiation dose delivered to 7 points in the heart was estimated for all patients who had received radiotherapy.

RESULTS

Cardiac disorder was diagnosed in 89 evaluated patients (39%) including 24 heart failures and 65 other asymptomatic cardiac diseases. When adjusting on potential confounders, cardiac disorder and cardiac failure risks were respectively linear (ERR at 1 Gy: 26%) and linear-quadratic (ERR at 1 Gy: 19%) functions of the average radiation dose received to the heart. No interaction between cumulative dose of adriamycin and average radiation dose was evidenced for cardiac disorders, but the ERR/Gy of cardiac failure was higher for patients receiving less than 350 mg/m(2) of Adriamycin.

CONCLUSION

Long term heart pathologies are probably one of the major iatrogenic risks encored by patients who survived a childhood cancer. This study strongly emphasizes the need to limit the heart irradiation during radiotherapy, particularly, for patients who also received or were susceptible to later received adriamycin.

Surviving childhood cancer: the impact on life

With modern therapies, most children diagnosed with cancer are expected to reach adulthood. Therefore, there are large and ever-increasing numbers of children and young adults in our population who are survivors of childhood cancer. Many of the therapies responsible for improved cancer survival rates can also damage normal cells and tissues. As more children survive cancer, the physical and emotional costs of enduring cancer therapy become increasingly important. Although most childhood cancer survivors are now expected to survive, they remain at risk for relapse, second malignant neoplasms, organ dysfunction, and a negative psychologic impact. Individual risk is quite variable and is dependent on multiple factors including the type and site of cancer, the therapy utilized, and the individual's constitution. The risks are likely to change as we learn more about the specific long-term effects of cancer therapy, develop more refined and targeted therapies, and develop and apply more effective preventative strategies or therapeutic interventions. Guidelines for long-term follow-up have been established and are available to help facilitate appropriate monitoring of and care for potential late effects.

The Effect of Radiation Therapy on Normal Tissue Function

As more patients are treated for their primary malignancy with cure or increased disease-free intervals, injury to normal tissues will become more detectable and an important endpoint for study. Future protocols will probably be modified based on toxicity endpoints. In Hodgkin's disease, current protocols use response-based treatment strategies to limit therapy. The objective is to provide the same level of tumor control and follow normal tissue endpoints for outcome analysis. DVH analysis has improved the ability to analyze endpoint data for normal tissues. These image-guided platforms will provide the infrastructure needed to continue efforts in improving the delivery of radiation therapy.

Is intensity-modulated radiotherapy better than conventional radiation treatment and three-dimensional conformal radiotherapy for mediastinal masses in patients with Hodgkin's disease, and is there a role for beam orientation optimization and dose constraints assigned to virtual volumes?

PURPOSE

To evaluate the role of beam orientation optimization and the role of virtual volumes (VVs) aimed at protecting adjacent organs at risk (OARs), and to compare various intensity-modulated radiotherapy (IMRT) setups with conventional treatment with anterior and posterior fields and three-dimensional conformal radiotherapy (3D-CRT).

METHODS AND MATERIALS

Patients with mediastinal masses in Hodgkin's disease were treated with combined modality therapy (three to six cycles of adriamycin, bleomycin, vinblastine, and dacarbazine [ABVD] before radiation treatment). Contouring and treatment planning were performed with Somavision and CadPlan Helios (Varian Systems, Palo Alto, CA). The gross tumor volume was determined according to the prechemotherapy length and the postchemotherapy width of the mediastinal tumor mass. A 10-mm isotropic margin was added for the planning target volume (PTV). Because dose constraints assigned to OARs led to unsatisfactory PTV coverage, VVs were designed for each patient to protect adjacent OARs. The prescribed dose was 40 Gy to the PTV, delivered according to guidelines from International Commission on Radiation Units and Measurements Report No. 50. Five different IMRT treatment plans were compared with conventional treatment and 3D-CRT.

RESULTS

Beam orientation was important with respect to the amount of irradiated normal tissues. The best compromise in terms of PTV coverage and protection of normal tissues was obtained with five equally spaced beams (5FEQ IMRT plan) using dose constraints assigned to VVs. When IMRT treatment plans were compared with conventional treatment and 3D-CRT, dose conformation with IMRT was significantly better, with greater protection of the heart, coronary arteries, esophagus, and spinal cord. The lungs and breasts in women received a slightly higher radiation dose with IMRT compared with conventional treatments. The greater volume of normal tissue receiving low radiation doses could be a cause for concern.

CONCLUSIONS

The 5FEQ IMRT plan with dose constraints assigned to the PTV and VV allows better dose conformation than conventional treatment and 3D-CRT, notably with better protection of the heart and coronary arteries. Of concern is the "spreading out" of low doses to the rest of the patient's body.

Cardiac complications of radiation therapy

AIMS

To present an overview of cardiac complications arising from radiation therapy.

MATERIALS AND METHODS

Medline the (February 2004) and Embase (1974 to February 2004) searches of the medical literature relating to the cardiac complications of radiotherapy were conducted.

RESULTS

Radiation damage may affect the pericardium, myocardium or coronary vasculature, and consists of fibrotic or small vessel damage. Cardiac complications are a particular problem with radiation treatments to the mediastinum and breast, especially when greater than 65% of the heart is irradiated. Most of the literature relates to the treatment of Hodgkin's disease, as patients with this disease tend to be young and live long enough to manifest late cardiac complications. Pericarditis, angina, myocardial infarction and arrhythmias are the most frequent causes of morbidity, with myocardial infarction being the most common fatal complication. The incidence of ischaemic heart disease does not increase rapidly until 10 years from treatment.

CONCLUSIONS

Much of the evidence relates to the use of outdated radiation therapy equipment and techniques. Today's patients almost certainly have a lower risk of cardiac complications. Cardiac complications are probably under-reported, as they occur long after cured patients have been discharged from follow-up.

Pathophysiology of anthracycline- and radiation-associated cardiomyopathies: implications for screening and prevention

Great progress has been made in treating childhood cancers over the past 40 years. Along with second malignancies, a major complication of anti-cancer therapies is adverse cardiovascular effects, especially cardiomyopathy and coronary artery disease. The pathophysiology and characteristics of cardiomyopathy associated with radiation therapy and anthracycline therapy are distinctive. We describe each type of cardiomyopathy, along with its risk factors. These distinctive cardiomyopathies require different screening tests. Appropriate screening of the entire cardiovascular system should be performed because radiation and chemotherapy affect the entire system. Prevention recommendations focus on cardiomyopathy and coronary artery disease.

Cardiovascular Status in Long-Term Survivors of Hodgkin's Disease Treated With Chest Radiotherapy

Purpose

Cardiovascular status was assessed in 48 Hodgkin's disease (HD) survivors at a median of 14.3 years (range, 5.9 to 27.5 years) after diagnosis because they may be at increased risk for cardiovascular abnormalities.

Patients and Methods

Patients completed the Short-Form 36 quality-of-life instrument and were screened by echocardiography, exercise stress testing, and resting and 24-hour ECG.

Results

All patients received mediastinal irradiation (median, 40.0 Gy; range, 27.0 to 51.7 Gy) at a median age of 16.5 years (range, 6.4 to 25.0 years). Four patients received an anthracycline. Although every patient described their health as good or better, and none had symptomatic heart disease at screening, all but one had cardiac abnormalities on screening. Restrictive cardiomyopathy was suggested by reduced average left ventricular (LV) dimension (P < .001) and mass (P < .001), without increased LV wall thickness. Significant valvular defects were present in 42%; 75% had conduction defects. One survivor developed complete heart block shortly after the study visit. Autonomic dysfunction was suggested by a monotonous heart rate in 57%, persistent tachycardia in 31%, and blunted hemodynamic responses to exercise in 27%. Peak oxygen uptake (VO2max) during exercise, a predictor of mortality in heart failure, was significantly reduced (< 20 mL/kg/m2) in 30% of survivors. VO2max was correlated with increasing fatigue, increasing shortness of breath (both, r = −0.35; P = .02), and decreasing physical component score on the SF-36 (r = 0.554; P = .00017).

Conclusion

A variety of unsuspected, clinically significant cardiovascular abnormalities are common in long-term survivors of HD who are treated at a young age with mediastinal irradiation. We recommend serial, comprehensive cardiac screening of HD survivors who fit this profile.

Asymptomatic cardiac disease following mediastinal irradiation

OBJECTIVES

This study was designed to evaluate the potential benefit of screening previously irradiated patients with echocardiography.

BACKGROUND

Mediastinal irradiation is known to cause cardiac disease. However, the prevalence of asymptomatic cardiac disease and the potential for intervention before symptom development are unknown.

METHODS

We recruited 294 asymptomatic patients (mean age 42 +/- 9 years, 49% men, mean mantle irradiation dose 43 +/- 0.3 Gy) treated with at least 35 Gy to the mediastinum for Hodgkin's disease. After providing written consent, each patient underwent electrocardiography and transthoracic echocardiography. Valvular disease was common and increased with time following irradiation. Patients who had received irradiation more than 20 years before evaluation had significantly more mild or greater aortic regurgitation (60% vs. 4%, p < 0.0001), moderate or greater tricuspid regurgitation (4% vs. 0%, p = 0.06), and aortic stenosis (16% vs. 0%, p = 0.0008) than those who had received irradiation within 10 years. The number needed to screen to detect one candidate for endocarditis prophylaxis was 13 (95% confidence interval [CI] 7 to 44) for patients treated within 10 years and 1.6 (95% CI 1.3 to 1.9) for those treated at least 20 years ago. Compared with the Framingham Heart Study population, mildly reduced left ventricular fractional shortening (<30%) was more common (36% vs. 3%), and age- and gender-adjusted left ventricular mass was lower (90 +/- 27 g/m vs. 117 g/m) in irradiated patients.

CONCLUSIONS

There is a high prevalence of asymptomatic heart disease in general, and aortic valvular disease in particular, following mediastinal irradiation. Screening echocardiography should be considered for patients with a history of mediastinal irradiation.