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Originally published as JCO Early Release 10.1200/JCO.2008.17.7428 on September 22 2008 © 2008 American Society of Clinical Oncology. Late Congestive Heart Failure After Hematopoietic Cell Transplantation
From the Division of Hematology/Oncology, Childrens Hospital Los Angeles; Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles; Divisions of Population Sciences and Hematology and Hematopoietic Cell Transplantation, City of Hope National Medical Center, Duarte, CA; and the Division of Pediatric Cardiology, University of Minnesota, Minneapolis, MN Corresponding author: Smita Bhatia, MD, MPH, City of Hope Cancer Center, 1500 East Duarte Rd, Duarte, CA 91010-3000; e-mail: sbhatia{at}coh.org
Purpose To examine the independent roles of pre–hematopoietic cell transplantation (HCT) therapeutic exposures, transplantation-related conditioning, and comorbidities (pre- and post-HCT) in the development of late congestive heart failure (CHF) after HCT.
Methods This was a nested case-control design. Individuals with late CHF (diagnosed
Results Sixty patients with late CHF were identified; median age at HCT was 45.3 years (range, 16.6 to 68.6 years); median time to CHF was 3.0 years (range, 1.03 to 18.9 years); 68% received autologous HCT. Median ejection fraction was 36.9% (range, 15% to 53%). Compared with matched controls (n = 166), patients with late CHF received more cycles of pre-HCT chemotherapy (8.6 v 4.9 cycles; P < .01), had greater body mass index at HCT (28.4 v 26.2 kg/m2; P = .01), greater lifetime anthracycline exposure (285.3 v 175.6 mg/m2; P < .01), and were more likely to have multiple chronic comorbidities (30.0% v 13.9%; P < .01). Multivariable analysis revealed number of pre-HCT chemotherapy cycles (odds ratio [OR] = 1.2; P < .01), anthracycline dose Conclusion Pre-HCT exposure to anthracyclines and presence of comorbidities are primarily responsible for the risk associated with late CHF after HCT. Conditioning-related therapeutic exposure does not contribute significantly to the risk. These results form the basis for identifying high-risk individuals for targeted surveillance, as well as developing preventive strategies in the form of aggressive management of comorbidities.
Hematopoietic cell transplantation (HCT) is being used increasingly with a curative intent for patients with life-threatening hematologic malignancies.1,2 Improvements in transplantation strategies and supportive care have contributed to incremental increase in survival rates of 10% per decade after HCT.3 Patients with hematologic malignancies who survive for 2 years after allogeneic HCT now have survival rates that exceed 80% at 15 years,4,5 whereas survival rates for autologous HCT recipients approach 70% at 10 years.6 The growing population of long-term survivors has brought to the medical forefront a host of chronic and debilitating conditions attributed to toxicity from pretransplantation exposure, transplantation conditioning regimens, infections, immunodeficiency, and graft-versus-host disease (GvHD).7-10 Congestive heart failure (CHF) is a well-described sequela during the immediate post-HCT period. Mortality attributed to early CHF ranges from 1% to 9% and morbidity from 5% to 43%,11-13 and well-defined risk factors have been identified.13-15 The occurrence of CHF after the first year (late CHF) is less well studied, with the few reports describing this outcome hampered by relatively short lengths of follow-up and small sample size.16,17 Potential mediators of late CHF could include pretransplantation exposure to known cardiotoxic agents such as anthracyclines, alkylating agents, and mediastinal radiation, compounded by high-dose cyclophosphamide and total-body irradiation (TBI) at the time of HCT and presence of chronic GvHD after HCT.18-21 Furthermore, the magnitude of this risk could be moderated by the presence of comorbid conditions, and host characteristics such as age at exposure and sex of recipient.9,18,22 The relative contribution of these factors in the development of late CHF and, in particular, the impact of HCT and its associated exposures is not known. We examined the independent roles of pre-HCT exposures, transplantation-related conditioning, and comorbidities (pre- and post-HCT) in the development of late CHF.
A nested case-control study design was used. Cases were identified from a cohort of 2,938 1+ year survivors who underwent transplantation at City of Hope National Medical Center (COH), Duarte, CA, between 1981 and 2003 for hematologic malignancies. To be eligible, patients were required to be free of cardiac disease before study entry and to have developed CHF after the first year after HCT, as defined by the American Heart Association (AHA)/American College of Cardiology (ACC) 2005 Guidelines for the Diagnosis and Management of Chronic Heart Failure in the Adult.23 Multiple controls (one to three) were selected at random from the same cohort and matched to patient cases for age at HCT (± 5 years), year of HCT (± 2 years), donor source (autologous v allogeneic), and length of follow-up. The human subjects committee at COH approved the protocol. Informed consent was obtained according to the Declaration of Helsinki.
Exposure Variables Therapeutic exposures were summarized for patient cases and controls. Anthracycline cardiotoxicity risk factor score16 was calculated by multiplying cumulative dose by a factor that reflects the cardiotoxic potential of each drug. Cumulative alkylating agent dose was recorded as a continuous variable; high-dose cyclophosphamide was recorded as a dichotomous variable.
Comorbidities Pre-HCT comorbidities, as well as post-HCT comorbidities that had developed after HCT but before the onset of CHF and were active at the time of event (cases) or equivalent follow-up (controls), were identified through medical record abstraction.
Outcome Variable: Late CHF Cases of late CHF identified from the long-term follow-up program were further validated using medical record information regarding history and physical examination at the time of CHF presentation. Diagnostic echocardiogram/multiple gate acquisition scan (MUGA) reports were used to document extent of cardiac compromise. Cases needed to satisfy ACC/AHA diagnostic guidelines of demonstrating symptoms (dyspnea and fatigue) and signs (edema and rales) consistent with CHF. Variables of interest were recorded and coded according to the recommendations of the ACC/AHA (2005) Task Force on Clinical Data Standards.24
Statistical Analysis
Multivariable conditional logistic regression was used to identify variables that were significantly and independently associated with late CHF after HCT (dependent variable). Variables included in the model were those significantly associated with late CHF in the univariate analysis, as well as those thought to impact clinical outcome, and included age at initial diagnosis, number of cycles of chemotherapy before HCT, and body mass index (BMI) as continuous variables and sex, primary diagnosis (lymphoma v nonlymphoma), anthracycline exposure (< 250 v
Sixty cases with late CHF and 166 matched controls were included in the analysis. All cases had at least one matched control; 58 cases (97%) had at least two controls. Median follow-up after HCT was 6.4 years (range, 1.3 to 22.1 years) for cases and 8.3 years (range, 1.5 to 25.1 years) for controls.
Patient Characteristics
Pre-HCT Treatment Exposures The mean time from diagnosis to HCT was comparable between cases and controls (2.6 v 1.7 years; P = .1). However, cases received a significantly greater number of courses of pre-HCT chemotherapy (8.6 v 4.9 courses; P < .01). Lifetime anthracycline exposure was also significantly higher among cases as compared with controls (285.3 v 175.6 mg/m2; P < .01). The proportion of patients exposed to mediastinal radiation did not differ between cases and controls.
HCT Conditioning
Comorbidities Median BMI at HCT was significantly greater among cases than among controls (28.4 v 26.2, respectively; P = .01). As seen in Table 2, cases were significantly more likely to have hypertension (40.0% v 14.5%; P < .01), chronic renal insufficiency (23.3% v 6.6%; P < .01), chronic lung disease (20.0% v 7.8%; P = .01), and diabetes (20.0% v 5.4%; P < .01) as compared with controls with equivalent follow-up. Cases were also significantly more likely to have multiple comorbidities (30.0% v 13.9%; P < .01) compared with controls. Among allogeneic HCT recipients, no statistically significant differences were observed regarding acute GvHD, history of ever having chronic GvHD, or presence of active GvHD (data not shown).
Clinical Presentation of Late CHF
Table 3 lists the clinical features of late CHF. Dyspnea on exertion was the most common presenting symptom (96.3%), followed by fatigue (90.7%), orthopnea (55.6%), and weight gain (48.6%). Fifty (92.6%) of the 54 cases reported at least three symptoms associated with CHF. Physical examination revealed extremity edema in 77.8% and decreased breath sounds or rales in 64.8% and 44.4% of the cases, respectively. Among the cases who had chest radiographs at the time of presentation (72% of all cases), pulmonary edema (83.7%) and cardiomegaly (69.8%) were the most frequently reported abnormalities.
Median left ventricular ejection fraction (EF) was 36.9% (range, 15% to 53%), and all assessable cases (n = 50) had greater than 10% reduction of EF from their pre-HCT baseline. Thirty-two cases (64%) were diagnosed with moderate to severe heart failure, characterized as having an EF of 40%. Forty-seven cases (78.3%) had stage C heart failure (structural heart disease with symptoms of CHF) and the remaining 13 cases (21.7%) had stage D disease (refractory CHF requiring specialized interventions), as defined by the ACC/AHA. Of the 60 patients with late CHF, 40 patients have died (overall survival, 49.8% at 2 years after CHF diagnosis). The most common causes of mortality were relapse/progression of primary disease (37.5%), infection (20%), and renal failure (10%). Heart failure was the primary cause of death in three cases (7.5%).
Risk Factors for Late CHF
Separate regression models were created for autologous and allogeneic HCT recipients to identify risk factors that may be unique to these populations. Excluded from both analyses were those individuals who underwent a second transplantation (eight cases and 12 controls). Among autologous HCT recipients (33 cases and 105 controls), female sex (OR = 4.6; P = .05), cumulative anthracycline dose (OR = 33.1; P = .02), pre-HCT cycles of chemotherapy (OR = 1.3; P = .02), and number of post-HCT comorbidities (OR = 77.8; P = .04) were significantly and independently associated with late CHF. For allogeneic HCT recipients (19 cases and 49 controls), documented history of having chronic GvHD was also included. Although a primary diagnosis of lymphoma, number of pre-HCT cycles of chemotherapy, and post-HCT comorbidities were identified to be significantly associated with late CHF, the small number of patients in this group precluded stable estimates (data not shown). Of note, no association was identified between chronic GvHD and late CHF.
The overall goal of this study was to understand the impact of HCT on the development of late CHF, over and above that of the well-known risks associated with conventional chemotherapy. Previous studies have limited the evaluation of post-HCT CHF to the first year after HCT, often focusing on conditioning-related exposures and immediate complications such as sepsis or multiorgan failure.11-13,15 It is increasingly recognized, however, that variables that lead to early CHF are different from those associated with late CHF. Our study was the first to incorporate pre-HCT therapeutic exposures, conditioning, and post-HCT exposures and comorbidities in the characterization of late CHF in a large cohort of HCT survivors. Using a nested case-control design, we identified number of pre-HCT chemotherapy cycles, cumulative anthracycline dose 250 mg/m2, and presence of post-HCT comorbidities to be significantly and independently associated with late CHF. Specifically, conditioning exposures such as high-dose chemotherapy, TBI, or other early transplantation-related complications, including GvHD, did not significantly increase the risk of late CHF.
Anthracyclines are the most commonly implicated agents for therapy-related cardiomyopathy.25 The incidence of anthracycline-related CHF in non-HCT populations varies from 4% at a cumulative dose of 500 to 550 mg/m2 to more than 36% in patients receiving 600 mg/m2.26 The incidence increases with follow-up, and the damage is often irreversible.18,27,28 The role of anthracyclines in the development of late CHF among HCT recipients is not clear, because most studies have evaluated them exclusively in the context of CHF within the first year after HCT. Our finding that cumulative dose of greater than 250 mg/m2 was associated with late CHF is the lowest threshold for anthracycline dose to be associated with CHF, supporting growing evidence that clinical cardiac dysfunction can occur at much lower doses than previously believed.18,29 The cardiotoxic effect of anthracyclines was higher for autologous HCT recipients, with a cumulative dose of Although anthracycline exposure was the primary variable of interest, number of chemotherapy cycles was included as a variable to serve as a surrogate for intensity of therapy. Our report that the number of chemotherapy cycles before HCT is significantly and independently associated with increased risk of late CHF after HCT is consistent with previous studies that have found direct correlation between the two variables.12,17 The case patients had received nearly twice as many cycles of chemotherapy compared with controls, and the difference remained significant despite adjustment for baseline demographics, diagnosis, time from diagnosis to HCT, and the cumulative anthracycline dose. This study demonstrates that, as anticipated, lifetime anthracycline exposure is associated with late CHF; in addition, there is an independent association of late CHF with the intensity of chemotherapeutic exposures. It is increasingly recognized that HCT survivors are at greater risk for developing comorbidities.7,9,31 However, little is known about the role of these conditions in exacerbating cardiac dysfunction. Comorbidities selected for the current study were those identified by the ACC/AHA as ones that contributed most to the risk of heart failure.24 More importantly, control of each of these diseases has been associated with reduction in risk of late CHF in the general population.24 After HCT, case patients were significantly more likely to have been diagnosed with hypertension, renal insufficiency, chronic lung disease, and diabetes when compared with controls. We found a four-fold increased risk of late CHF for those with multiple post-HCT comorbidities, despite adjustment for patient demographics, pre-HCT comorbidities, and BMI. Stratifying the analysis by donor source (allogeneic and autologous) revealed that among autologous transplant recipients, women had a greater than four-fold increased risk of late CHF. This is consistent with previous reports in autologous HCT recipients.6,32 A similar observation has been reported in long-term survivors of childhood cancer, where female sex and cumulative anthracycline dose were the most consistent predictors of late CHF.32,33 The mechanism for sex-specific association with CHF is not clear. Differences in body fat composition between men and women could alter the pharmacokinetics and pharmacodynamics of the drug, because anthracyclines do not reach a high concentration in adipose tissue.33,34 If women have a higher percentage of body fat for the same body-surface area, equivalent doses of the drug could lead to greater concentrations in nonadipose tissues such as the heart and lead to more cardiotoxicity than their male counterparts.35,36 Any retrospective review of medical records is limited by the amount of information available for review. Lack of consistency with which data were recorded in medical charts by health care staff could have influenced the validity of the information collected. To prevent recorder bias, pre-HCT treatment information obtained from the institutional screening history and physical examination was confirmed with the treatment summary submitted by the referring primary oncologist. The definition of clinical heart failure is based as much on clinical signs and symptoms as it is on demonstration of reduced cardiac function on echocardiogram or MUGA. The recent position statement by the ACC/AHA has described heart failure as a syndrome, characterized by specific symptoms (dyspnea and fatigue) in the medical history and signs (edema and rales) on physical examination.23 All cases had clinical evidence of heart failure (stage C or D), and we were able to obtain corresponding echocardiograms or MUGA on most patients to demonstrate reduced cardiac function from baseline. Our cases did not include those individuals who may have had diminished cardiac function but were asymptomatic. However, the focus of this study was on understanding the impact of HCT-related exposures and events on the development of late clinical heart failure, and as such, asymptomatic CHF would not fit this definition. In summary, we found that pre-HCT exposure to anthracyclines and the presence of post-HCT chronic comorbidities to be associated with an increased risk of late CHF after HCT. High-dose chemotherapy or TBI used for conditioning did not contribute significantly to the risk. These data form the basis of developing predictive models for identifying those at risk for targeted surveillance, as well as developing preventive strategies in the form of aggressive management of comorbidities.
The author(s) indicated no potential conflicts of interest.
Conception and design: Saro H. Armenian, Can-Lan Sun, Smita Bhatia Administrative support: Stephen J. Forman, Smita Bhatia Provision of study materials or patients: Saro H. Armenian, Liton Francisco, Seira Kurian, Jon Sharp, Smita Bhatia Collection and assembly of data: Saro H. Armenian, Liton Francisco, F. Lennie Wong, Jon Sharp, Smita Bhatia Data analysis and interpretation: Saro H. Armenian, Can-Lan Sun, Julia Steinberger, Richard Sposto, Smita Bhatia Manuscript writing: Saro H. Armenian, Can-Lan Sun, Julia Steinberger, Seira Kurian, F. Lennie Wong, Richard Sposto, Smita Bhatia Final approval of manuscript: Saro H. Armenian, Can-Lan Sun, Liton Francisco, Julia Steinberger, Seira Kurian, F. Lennie Wong, Jon Sharp, Richard Sposto, Stephen J. Forman, Smita Bhatia
published online ahead of print at www.jco.org on September 22, 2008 Supported by National Institutes of Health Grants No. R01 CA078938 (S.B.) and P01 CA30206 (S.J.F.), Lymphoma/Leukemia Society Scholar Award for Clinical Research Grant No. 2191-02 (S.B.), and Childrens Hospital Los Angeles Research Career Development Fellowship (S.H.A.). Presented in part at the 44th Annual Meeting of the American Society of Clinical Oncology (Clinical Science Symposium: Treatment-Related Cardiovascular Disease in Survivors of Pediatric and Adult Cancers), May 30-June 3, 2008, Chicago, IL. Authors disclosures of potential conflicts of interest and author contributions are found at the end of this article.
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Copyright © 2008 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
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