Monitoring of cardiac function by serum cardiac troponin T levels, ventricular repolarisation indices, and echocardiography after conditioning with fractionated total body irradiation and high-dose cyclophosphamide

New insights into the potential cardioprotective effects of telmisartan and nanoformulated extract of Spirulina platensis via regulation of oxidative stress, apoptosis, and autophagy in an experimental model

Background

Cardiotoxicity is one of the limiting side effects of the commonly used anticancer agent cyclophosphamide (Cyclo).

Materials and methods

The possible protective effects of telmisartan and nanoformulated Spirulina platensis (Sp) methanolic extract against Cyclo-induced cardiotoxicity were examined in this study. Experimental groups of rats were randomly divided into nine groups as control vehicle, control polymer, telmisartan (TEL, 10 mg/kg), free Sp extract (300 mg/kg), nano Sp extract (100 mg/kg), Cyclo (200 mg/kg), TEL + Cyclo, free Sp + Cyclo, and nano Sp + Cyclo. The groups with Cyclo combinations were treated in the same manner as their corresponding ones without Cyclo, with a single dose of Cyclo on day 18.

Results

The results indicate that Cyclo causes significant cardiotoxicity, manifesting in the form of notable increases of 155.49%, 105.74%, 451.76%, and 826.07% in the serum levels of glutamic oxaloacetic transaminase (SGOT), lactate dehydrogenase (LDH), creatine kinase MB (CK-MB), and cardiac troponin I (cTnI) enzyme activities, respectively, as compared to the control. In addition, the cardiac glutathione (GSH) content and activity of glutathione peroxidase-1 (GPX-1) enzyme decreased by 65.94% and 73.85%, respectively. Treatment with nano Sp extract showed the most prominent restorations of the altered biochemical, histopathological, and immunohistochemical features as compared with those by TEL and free Sp; moreover, reductions of 30.64% and 43.02% in the p-AKT content as well as 60.43% and 75.30% of the endothelial nitric oxide synthase (eNOS) immunoreactivity were detected in the TEL and free Sp treatment groups, respectively. Interestingly, nano Sp boosted the autophagy signal via activation of beclin-1 (36.42% and 153.4%), activation of LC3II (69.13% and 195%), downregulation of p62 expressions (39.68% and 62.45%), and increased gene expressions of paraoxonase-1 (PON-1) (90.3% and 225.9%) compared to the TEL and free Sp treatment groups, respectively.

Conclusion

The findings suggest the protective efficiency of telmisartan and nano Sp extract against cardiotoxicity via activations of the antioxidant, antiapoptotic, and autophagy signaling pathways.

Cardiotoxicity in Hematopoietic Stem Cell Transplant: Keeping the Beat

INTRODUCTION

The number of hematopoietic stem cell transplants (HSCTs) performed in the United States and worldwide is increasing. Cardiac events have been well described in HSCT, and the incidence and type of cardiac events have not changed over recent decades.

PATIENTS AND METHODS

This study adds to the body of evidence in describing the incidence and type of cardiac events experienced by an allogeneic and autologous HSCT population at a single institution from 2012 to 2017.

RESULTS

Sixty-five (9.8%) patients experienced cardiac events, including atrial arrhythmia (N = 39), acute heart failure (N = 9), acute coronary syndrome (N = 7), and new onset hypertension (N = 9), with a few instances of bradycardia, ventricular arrhythmia, pericardial effusion, and pericarditis. Our multivariable regression analysis identified age (older), creatinine (higher), and history of coronary artery disease to significantly correlate with risk of cardiac event (P = .005, P = .039, and P = .038, respectively). A subgroup analysis of those patients experiencing a cardiac event found pre-transplant atrial dilation by trans-thoracic echocardiogram to correlate with increased risk of atrial arrhythmia (33.8% vs. 9.7%; P = .03). Patients developing a CE had an increased risk of death within 1 year (11% vs. 32%; P < .001).

CONCLUSION

We review our results in context of other important HSCT cardiac studies to illuminate the most relevant factors of medical history, laboratory data, and cardiac measurements that will identify patients at higher risk, allowing for intervention to improve HSCT outcomes.

The analysis of the parameters of 24-hr ECG Holter monitoring in patients with blood neoplasms undergoing high-dose chemotherapy and stem cell transplantation

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is a widely used procedure in the treatment of malignant diseases, including blood neoplasms and has increased survival in hematological diseases. The aim of the study was to analyze parameters of 24-hr ECG monitoring in patients with selected blood neoplasms in whom the procedure of hematopoietic stem cell transplantation was performed.

METHODS

The study group consisted of 64 adults diagnosed with hematologic cancer qualified for HSCT with the previous high dose chemotherapy (HDC). In all patients 24-hr Holter monitoring was carried out twice. First examination took place prior to the HSCT procedure, and the second after finishing the procedure of HSCT.

RESULTS

The minimal and mean heart rate (HR min and HR max) from 24-hr ECG recording was statistically significantly higher after the transplantation in comparison with the first test. The number of premature ventricular complexes (PVCs) was higher in the test after HSCT. In the second examination there was significantly higher percentage of premature ventricular complexes, incidents of tachycardia, and Mobitz type 1 second degree atrioventricular block. In regression analysis, in a group of patients with blood neoplasms after HSCT and HDC, administration of cyclophosphamide, fludarabine and total body irradiation were independent risk factors for electrocardiographic abnormalities in 24-hr Holter monitoring, that is, the increase in HR min, HR mean and PVCs.

CONCLUSION

In patients with blood neoplasms undergoing HSCT more electrocardiographic abnormalities may be found after this procedure in comparison with the 24-hr Holter monitoring before transplantation.

Acute Cyclophosphamide Hemorrhagic Myopericarditis: Dilemma Case Report, Literature Review and Proposed Diagnostic Criteria

Cyclophosphamide is a potent DNA alkylating agent used in chemotherapy and immunosuppression. Although an old agent, its use in the present day has expanded for cases of refractory autoimmune disease. In this report, a case of haemorrhagic myopericarditis resulting from high-dose cyclophosphamide for chronic inflammatory demyelinating polyneuropathy is presented. The patient had no predisposing cardiovascular risk factors and a structurally normal heart on previous echocardiogram. Following administration of high-dose cyclophosphamide, the patient developed acute congestive heart failure. Serial echocardiography demonstrated pericardial effusion, myocardial thickening, and progressive right ventricular dysfunction. Histopathology on autopsy revealed acute myocardial necrosis, intra-myocardial extravasation of blood, fibrin, and fibrin-platelet microthrombi compatible with the diagnosis of haemorrhagic myopericarditis. The ante-mortem diagnostic dilemma is described to emphasize the need for pattern recognition and clinical criteria for diagnosis. Subsequent comprehensive literature review was performed to identify features that will facilitate earlier diagnosis of haemorrhagic myopericarditis by healthcare providers.

Use of biomarkers for the assessment of chemotherapy-induced cardiac toxicity

OBJECTIVES

To review the evidence for the use of various biomarkers in the detection of chemotherapy associated cardiac damage.

DESIGN AND METHODS

Pubmed.gov was queried using the search words chemotherapy and cardiac biomarkers with the filters of past 10years, humans, and English language. An emphasis was placed on obtaining primary research articles looking at the utility of biomarkers for the detection of chemotherapy-mediated cardiac injury.

RESULTS

Biomarkers may help identify patients undergoing treatment who are at high risk for cardiotoxicity and may assist in identification of a low risk cohort that does not necessitate continued intensive screening. cTn assays are the best studied biomarkers in this context and may represent a promising and potentially valuable modality for detecting cardiac toxicity in patients undergoing chemotherapy. Monitoring cTnI levels may provide information regarding the development of cardiac toxicity before left ventricular dysfunction becomes apparent on echocardiography or via clinical symptoms. A host of other biomarkers have been evaluated for their utility in the field of chemotherapy related cardiac toxicity with intermittent success; further trials are necessary to determine what role they may end up playing for prediction and prognostication in this setting.

CONCLUSIONS

Biomarkers represent an exciting potential complement or replacement for echocardiographic monitoring of chemotherapy related cardiac toxicity which may allow for earlier realization of the degree of cardiac damage occurring during treatment, creating the opportunity for more timely modulation of therapy.

Cardiac complications of chemotherapy: role of biomarkers

OPINION STATEMENT

Both conventional and novel antineoplastic drugs may cause damage to the heart, ultimately affecting patients' survival and quality of life. In fact, the most frequent and typical clinical manifestation of cardiotoxicity, asymptomatic or symptomatic left ventricular dysfunction, may be induced not only by conventional cancer therapy, like anthracyclines, but also by new antitumoral targeted therapy such as trastuzumab. At present, left ventricular ejection fraction assessment represents the main standard practice for cardiac monitoring during cancer therapy, but it detects myocardial damage only when a functional impairment has already occurred, not allowing for early preventive strategies. In the last decade, a newer approach based on the measurement of cardiospecific biomarkers has been proposed, proving to have higher prognostic value than imaging modalities. In particular, cardiac troponin elevation during chemotherapy allows us to identify patients who are more prone to develop myocardial dysfunction and cardiac events during follow up. In these patients, the use of an angiotensin-converting enzyme inhibitor, such as enalapril, has shown to be effective in improving clinical outcome, giving the chance for a cardioprotective strategy in a selected population.

Cardiac toxicity of anticancer agents

Modern cancer therapies are highly effective in the treatment of various malignancies, but their use is limited by the potential for cardiotoxicity. The most frequent and typical clinical manifestation of cardiotoxicity is left ventricular dysfunction, induced not only by cytotoxic conventional cancer therapy like anthracyclines, but also by new antitumor targeted therapy such as trastuzumab. The current standard for monitoring cardiac function, based on periodic assessment of left ventricular ejection fraction detects cardiotoxicity only when a functional impairment has already occurred, precluding any chance of preventing its development. A novel approach, based on the use of cardiac biomarkers has emerged in the last decade, resulting in a cost-effective diagnostic tool for early, real-time identification, assessment and monitoring of cardiotoxicity. In particular, prophylactic treatment with enalapril in patients with an early increase in troponin after chemotherapy has been shown to be very effective in preventing left ventricular dysfunction and associated cardiac events. In patients developing cancer treatment induced-cardiomyopathy, complete left ventricular ejection fraction recovery and a reduction of cardiac events may be achieved only when left ventricular dysfunction is detected early after the end of cancer treatment and treatment with angiotensin-converting enzyme inhibitors, possibly in combination with beta-blockers, is promptly initiated.

Using cardiac biomarkers and treating cardiotoxicity in cancer

Cardiotoxicity is a frequent and serious adverse effect of both conventional and novel anticancer treatments, affecting patient survival and quality of life. The current standard for cardiac monitoring during cancer therapy, mainly based on left ventricular ejection fraction assessment, detects myocardial damage only when a functional impairment has already occurred, not allowing for early preventive strategies. Measurement of cardiospecific biomarkers has proven to have higher prognostic value than imaging modalities. In particular, cardiac troponin elevation during chemotherapy allows the identification of patients who are more prone to develop myocardial dysfunction and cardiac events during follow-up. In these patients, the use of an angiotensin-converting enzyme inhibitor such as enalapril has shown to be effective in improving clinical outcome, giving the chance for a cardioprotective strategy in a selected population. Once left ventricular dysfunction occurs, heart failure therapies currently used for other forms of left ventricular dysfunction, particularly angiotensin-converting enzyme inhibitors and β-blockers, seem to be effective. However, their use in cancer patients is still undervalued.

Cyclophosphamide-Induced Cardiomyopathy: A Case Report, Review, and Recommendations for Management

Cyclophosphamide is increasingly used to treat various types of cancers and autoimmune conditions. Higher doses of this drug may produce significant cardiac toxicity, including fatal hemorrhagic myocarditis. In this review, we present a case of cyclophosphamide-induced cardiomyopathy requiring mechanical circulatory support. We also describe the pathophysiology, clinical manifestations, and risk factors for this important clinical entity and propose early detection and management strategies.

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.

Serial measurements of cardiac biomarkers in patients after allogeneic hematopoietic stem cell transplantation

Background

Previous therapy with anthracyclines (ANT) and conditioning regimen followed by hematopoietic stem cell transplantation (HSCT) represents a high risk for development of cardiotoxicity. The aim of this study was to assess subclinical myocardial damage after HSCT using echocardiography and cardiac biomarkers - high sensitive cardiac troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) and to identify patients at risk of developing clinical cardiotoxicity.

Patients and methods

Thirty-seven patients who were treated with allogeneic HSCT for hematologic diseases at median age of 28 years at time of HSCT were studied. Conditioning regimen included either chemotherapy without total body irradiation (TBI) or combination of chemotherapy with TBI. Twenty-nine (78,3%) patients were pretreated with ANT therapy. Cardiac biomarkers were serially measured before conditioning regimen and at days 1, 14 and 30 after HSCT. Cardiac systolic and diastolic functions were assessed before conditioning regimen and 1 month after HSCT by echocardiography.

Results

The changes in plasma NT-proBNP and hs-cTnT levels during the 30 days following the HSCT were statistically significant (P < 0,01 v.s. P < 0,01). Persistent elevations of NT-proBNP and hs-cTnT simultaneously for a period exceeding 14 days after HSCT were found in 29,7% patients. Serum concentrations of cardiomarkers were significantly elevated in ANT group compared to non-ANT group. These observations were underscored by the echocardiographic studies which did reveal significant changes in systolic and diastolic parameters. Five of 37 (13,5%) patients developed clinical manifestation of cardiotoxicity.

Conclusions

Elevations in both cardiac biomarkers were found before clinical signs of cardiotoxicity developed. Persistent elevations in NT-pro-BNP and hs-cTnT concentrations simultaneously for a period exceeding 14 days might be used for identification of patients at risk of developing cardiotoxicity and requiring further cardiological follow up.

Late potentials and QT dispersion after high-dose chemotherapy in patients with non-Hodgkin lymphoma

The most common cardiotoxic effects of high-dose cyclophosphamide (CY) are electrocardiographic changes and transient arrhythmias. Therefore, we prospectively assessed serial electrocardiogram (ECG) and signal-averaged electrocardiogram (SAECG) recordings in 30 adult patients with non-Hodgkin lymphoma (NHL) receiving high-dose CY as part of high-dose chemotherapy (HDT) regimen. All patients were treated with anthracyclines earlier. Heart-rate-corrected QT interval and QT dispersion (QTc and QTc dispersion) were measured from ECG. QRS duration and late potentials (LPs) were analysed from SAECG. Both ECG and SAECG were recorded 1 day (d) prior to HDT (d-7) at baseline, and 1 day (d-2), 7 days (d+7), 12 days (+12) and 3 months (m+3) after HDT. Stem cells were infused on day 0 (d0). Cardiac systolic and diastolic function were assessed on (d-7), (d+12) and (m+3) by radionuclide ventriculography. At baseline, four patients presented with LPs. Cardiac systolic function decreased significantly (53 +/- 2; 49 +/- 2%, P = 0.009 versus baseline), whilst no patient developed acute heart failure. QRS duration prolonged and RMS(40) reduced significantly versus baseline (104 +/- 3; 107 +/- 3 ms, P = 0.003; 41 +/- 4; 38 +/- 3 microV, P = 0.03), and six patients (21%) presented with LPs after CY treatment. Both QTc interval and QTc dispersion increased versus baseline (402 +/- 5; 423 +/- 5 ms, P<0.001; 32 +/- 2; 44 +/- 3 ms, P = 0.012), and six patients (20%) developed abnormal QT dispersion. In conclusion, high-dose CY causes subclinical and transient electrical instability reflected by occurrence of LPs as well as increased QTc interval and QT dispersion. Thus, longer follow-up is required to confirm the meaning of these adverse effects on cardiac function and quality of life.

Cardiac toxicity of high-dose cyclophosphamide and melphalan in patients with multiple myeloma treated with tandem autologous hematopoietic stem cell transplantation

Tandem autologous hematopoetic stem cell transplantation (HSCT) is an effective treatment in patients with multiple myeloma (MM). Patients receive high-dose cyclophosphamide (CY) followed by two myeloablative dosages of melphalan (MEL). Cardiotoxicity treatment related data are scanty. In 30 patients with MM chemotherapy was followed by high-dose CY (cycle CY), and two autologous tandem HSCT treatments with MEL (cycles MEL I and MEL II). During each 15-day treatment troponin I (TnI), brain natriuretic peptide (BNP) and endothelin-1 (ET-1) were controlled at six time points. All patients underwent conventional and tissue Doppler echocardiography prior to CY therapy (Eho 0), before cycle MEL I (Eho 1), before cycle MEL II (Eho 2), and 3 months after the completion of therapy (Eho 3). None of the patients developed clinical signs of heart failure. The peak TnI concentrations were noted at days 8, 11, and 15 during all three chemotherapy cycles. During all three cycles there was a significant increase in baseline BNP concentrations and BNP levels measured at day 1 after treatment with CY and MEL (CY: P = 0.0001, MEL I: P = 0.001, MEL II: P = 0.001). The highest BNP concentration occurred during CY treatment (0.517 +/- 0.391 microg/L). During cycles MEL I and MEL II we noted the peak BNP concentrations at day 4 following chemotherapy (MEL I 0.376 +/- 0.418 microg/L; MEL II 0.363 +/- 0.379 microg/L). During all three cycles the highest ET-1 levels occurred at day 1 after chemotherapy (CY 1.146 +/- 1.313 ng/L; MEL I 1.054 +/- 2.242 ng/L; MEL II 0.618 +/- 0.539 ng/L). A significant increase in ET-1 concentrations relative to the basal values occurred only in cycle MEL II (P = 0.003). The duration of wave a in the Doppler pulmonary vein flow increased significantly (Eho 0/Eho 1: P = 0.008, Eho 0/Eho 3: P = 0.026). There was a significant decrease in the A/a ratio in flow velocities during chemotherapy (Eho 0/Eho 1: P = 0.002, Eho 0/Eho 3: P < 0.0001). Early diastolic tissue Doppler velocities (Em) decreased significantly during individual cycles of chemotherapy (P = 0.006). A significant post-treatment increase in the incidence of mitral regurgitation was observed (Eho 0/Eho 3: P = 0.003). Treatment of MM patients with tandem autologous HSCT is cardiotoxic. Our patients did not develop clinically overt heart failure or myocardial necrosis. Increased plasma levels of BNP and ET-1 were compatible with transient neurohormonal activation of heart failure. Doppler echocardiography studies revealed worsening of left ventricular diastolic function and occurrence of functional mitral regurgitation.

Critical care considerations of hematopoietic stem cell transplantation

OBJECTIVE

To review the available clinical data on the critical care complications of hematopoietic stem cell transplantation (HSCT).

DATA SOURCE

The MEDLINE database and references from the identified articles related to the critical care in HSCT.

CONCLUSION

HSCT is an important treatment for a variety of malignant and nonmalignant conditions. The procedure is, however, limited by significant complications that may involve every organ of the body. Up to 40% of HSCT recipients are admitted to the intensive care unit as a result of severe complications related to the transplantation. The outcome of those critically ill patients has been traditionally poor. However, recent advances in the transplantation procedure, diagnostic studies, antimicrobial prophylaxis and therapy, and intensive care unit care have improved the outcome of these patients. The increasing number of HSCTs performed annually, the unique complications that develop in these patients, and the improvement in the intensive care unit outcome make knowledge about the critical care aspect of HSCT an essential part of the current practice of critical care medicine.

Cardiac effects within 3 months of BEAC high-dose therapy in non-Hodgkin's lymphoma patients undergoing autologous stem cell transplantation

OBJECTIVES

Limited data are available on the cardiac effects of high-dose cyclophosphamide (CY) in patients with non-Hodgkin's lymphoma (NHL). We prospectively assessed the cardiac effects of high-dose CY in 30 adult NHL patients receiving CY 6 g/m(2) as part of BEAC high-dose therapy (HDT).

METHODS

Radionuclide ventriculography (RVG) and plasma natriuretic peptide (NT-proANP, NT-proBNP) measurements were performed simultaneously prior to BEAC at baseline (d - 7), 12 days (d + 12) and 3 months (m + 3) after stem cell infusion (D0). In addition to these time points, natriuretic peptides were measured 2 days before (d - 2) and 1 week (d + 7) after stem cell infusion.

RESULTS

Left ventricular ejection fraction (LVEF) decreased from d - 7 (53% +/- 2%) to d + 12 (49% +/- 2%, P = 0.009). However, no significant change in cardiac diastolic function was observed. The LVEF returned towards baseline by m + 3. Plasma NT-proANP and NT-proBNP increased significantly from baseline (445 +/- 65 pmol/L and 129 +/- 33 pmol/L) to d - 2 (1,127 +/- 142 pmol/L, P < 0.001 and 624 +/- 148 pmol/L, P < 0.001, respectively). Thereafter, they started to decrease, but on d + 7 NT-proANP (404 +/- 157 pmol/L, P = 0.048) and NT-proBNP (648 +/- 125 pmol/L, P = 0.015) were still significantly higher than at baseline. On d + 12 and m + 3 they no longer differed from baseline.

CONCLUSIONS

Our findings suggest that high-dose CY results in acute, subclinical systolic dysfunction in NHL patients previously treated with anthracyclines. Natriuretic peptides seem to be more sensitive than LVEF to reflect this transient cardiac effect. Serial measurements of natriuretic peptides might be a useful tool to assess cardiac effects of high-dose CY.

Troponin as a marker of myocardiac damage in drug-induced cardiotoxicity

Cardiac troponins T and I (cTnT and cTnI) are becoming the serum biomarkers of choice for monitoring potential drug-induced myocardial injury in both clinical and preclinical studies. The utility of cardiac troponins has been mainly demonstrated following the administration of antineoplastic drugs and beta-sympathomimetics, although the routine use of these markers in the monitoring in patients who received anthracyclines therapy is far from settled. Unlike the previous markers, which suffered from numerous shortages, the main advantages of cardiac troponins are their high specificity and sensitivity, wide diagnostic window and the possibility to use commercially available assays in clinical settings as well as in a broad range of laboratory animals. Nevertheless, in spite of vigorous research in this area, a number of questions are still unanswered and these are discussed in this review. The main problems seem to be the lack of standardisation of variety of troponin immunoassays, the assessment of suitable cutoff for drug-induced cardiotoxicity and determination of critical diagnostic window related to the optimal timing of sample collection, which may be drug-dependent.

Cardiac troponins as biomarkers of drug- and toxin-induced cardiac toxicity and cardioprotection

Cardiac troponin T and I (cTnT, cTnI) are sensitive biochemical markers of myocardial cell necrosis and have been adopted as the gold standard tests for acute myocardial infarction. Subtle elevations in cTn above the detection limits of the currently available commercial assays confers poor prognosis. These markers are superior to classical enzyme markers of necrosis due to their cardiospecificity. The diagnosis of drug-induced cardiac toxicity using the classical enzymes is problematic due to the high elevations of these markers in skeletal muscle necrosis. cTnT and cTnI are now being adopted as sensitive biomarkers of drug-induced cardiac toxicity.

Cardiac toxicity of high-dose chemotherapy

Cardiac toxicity is an uncommon but potentially serious complication of high-dose (HD) chemotherapy and little is known about incidence, severity and underlying mechanisms. We have systematically reviewed the literature of the last 30 years to summarize and appraise the published evidence on cardiac toxicity associated with HD chemotherapy. HD cyclophosphamide-containing regimens have been most commonly associated with cardiac toxicity, with a progressively decreasing incidence over time. Dosage, application regimens and coadministration of other chemotherapeutic agents emerged as risk factors. While cardiac toxicity has been rarely associated with other cytotoxic drugs, an unexpected incidence of severe cardiotoxicity resulted from reduced-intensity conditioning regimens containing melphalan and fludarabine. Predictive value of cardiologic examination of patients is limited, and patients with a slight depression of cardiac performance could tolerate HD chemotherapy. Clinical examination, resting electrocardiography and dosage adjustment in overweight patients remain the mainstay of prevention, with bidimensional echocardiography (2D echo) for patients with a history of anthracycline exposure. Strategies to decrease the long-term negative impact of anthracycline administration on cardiac performance are being investigated. New 2D echo-based techniques and circulating markers of cardiac function hold promise for allowing identification of patients at high risk for and early diagnosis of cardiac toxicity.

Monitoring of cardiac function on the basis of serum troponin I levels in patients with acute leukemia treated with anthracyclines

Anthracyclines are used extensively in the therapy of hematologic malignancies. However, their use has been limited by acute and chronic cardiotoxicity. Cardiac troponins have emerged as sensitive and specific markers of even minor myocardial damage. In this study we prospectively evaluated serial measurements of serum cardiac markers and echocardiography in patients with de novo acute myeloid and lymphoid leukemias (AML and ALL, respectively) treated with anthracyclines. We examined and subdivided 79 patients into 3 groups: group 1 (37 patients with AML, all < 60 years), group 2 (25 with AML, all 260 years), group 3 (17 with ALL). Serum specimens were collected before treatment and during and after therapy and were analyzed for troponin I (Tnl), myoglobin, creatine phosphokinase-muscle myocardium isoenzyme B, and lactate dehydrogenase concentrations. In group 1, 4 of the 37 patients (11%) had increased levels of Tnl on the 14th day of induction therapy, but by the 28th day the Tnl level had returned to normal in 3 of these 4 patients. In group 2, 3 of the 25 patients (12%) demonstrated increased Tnl concentrations on the 7th day of induction therapy, but by the 14th day these levels had normalized in 2 of the 3. In group 3, we detected no increased Tnl concentrations. Echographic study did show a significant correlation with the Tnl levels (P < .001), involving a reversible decrease in left ventricular ejection fraction among patients with increased Tnl levels (> 0.15 ng/mL) on day 14 in group 1 and on day 7 in group 2. These results may aid the clinician in the treatment of patients by identifying high-risk patients who may benefit from closer observation or supportive cardiac therapy.

Predictive value of QT dispersion for acute heart failure after autologous and allogeneic hematopoietic stem cell transplantation

The aim of our study was to evaluate whether corrected QT dispersion (QTc dispersion), an electrocardiographic marker, is a good predictor of the development of acute heart failure after high-dose chemotherapy followed by autologous or allogeneic hematopoietic stem cell transplantation. We enrolled 50 consecutive patients, from age 15 to 63 years, with hematopoietic diseases scheduled to undergo autologous or allogeneic hematopoietic stem cell transplantation, and compared QTc dispersion with other markers before transplantation conditioning. In univariate logistic analysis, QTc dispersion was a significant factor for acute heart failure after hematopoietic stem cell transplantation (odds ratio, 3.7 per 10 msec; confidence interval, 1.6-8.5; P = 0.002). There were no significant differences as age, sex, systolic or diastolic echocardiographic function markers, cumulative anthracycline dose, or QTc before transplantation between patients with and without acute heart failure. After multiple adjustments for left ventricular ejection fraction, cumulative anthracycline dose, cyclophosphamide conditioning dose, QTc dispersion was a significant and independent factor for acute heart failure after hematopoietic stem cell transplantation (odds ratio, 48.0 per 10 msec; confidence interval, 1.4-1666.3; P = 0.03). This study demonstrated that QTc dispersion could be used as a powerful noninvasive predictor of the development of acute heart failure after hematopoietic stem cell transplantation.

The Influence of Anthracycline Therapy on Cardiac Function During Anesthesia

Cardiotoxicity is a well recognized complication of anthracycline (AC) therapy. Subtle abnormalities in myocardial function that become apparent only after exercise may exist in survivors of childhood cancer who have previously received AC, yet have normal resting cardiac function. To evaluate if anesthesia-induced changes in cardiac function differ in pediatric patients with previous AC therapy from healthy children and adolescents, we evaluated in a prospective study 43 patients, of whom 42 were analyzed. Twenty-one patients (AC-group), mean age 9.6 yr (range, 3-16 yr), who had received 193 (30-490) mg/m(2) of AC as a mean cumulative dose with normal resting cardiac function (shortening fraction [SF] 0.34, normal value > 0.30) underwent removal of a Hickman catheter under general anesthesia. Twenty-one patients, mean age 10.9 yr (range, 4-17 yr), who underwent placement of a Hickman catheter before chemotherapy served as the control. All children were premedicated with midazolam 0.5 mg/kg orally. Anesthesia was induced by sodium thiopental (5 mg/kg), fentanyl (3 micro g/kg), and rocuronium (0.6 mg/kg) and maintained with isoflurane (1 MAC) in N(2)O/O(2) (70/30). Before induction (baseline), 5 and 20 min after intubation (T1 and T2), and 20 min after extubation (control), cardiac function was assessed by transthoracic (baseline, control) and transesophageal (T1, T2) echocardiography. Compared with baseline (SF: 34.9 +/- 3.7 [AC], 34.1 +/- 3.7 [C] [not significant]; stroke volume index [SVI] 36 +/- 6 mL/m(2)[AC], 35 +/- 4 mL/m(2)[C] [not significant]; cardiac index [CI] 3.6 +/- 0.6 L/min/m(2)[AC], 3.2 +/- 0.5 L/min/m(2)[C] [not significant]), we found a significant decrease in SF and SVI in both groups at T1 (SF: 26.2 +/- 3.6 [AC] versus 28.6 +/- 3.6 [C] [P < 0.05]; SVI: 26 +/- 4 mL/m(2) [AC] versus 30 +/- 46 mL/m(2) [C] [P < 0.05]) and T2 (SF: 24.1 +/- 3.2 [AC] versus 28.2 +/- 2.5 [C] [P < 0.01], SVI: 26 +/- 6 mL/m(2) [AC] versus 31 +/- 5 mL/m(2) [C] [P < 0.01]), which was significantly greater in the AC group. There were no significant changes of variables of diastolic function (E/A ratio, isovolumetric relaxation time) between both groups. Previous treatment with AC may enhance the myocardial depressive effect of anesthetics even in patients with normal resting cardiac function.

IMPLICATIONS

Previous treatment with anthracylines, a group of chemotherapeutic drugs in use for childhood cancer, may enhance the myocardial depressive effect of anesthetics even in children and adolescents with normal resting cardiac function.

Prolonged monitoring of troponin T for the detection of anthracycline cardiotoxicity in adults with hematological malignancies

The study was performed to describe the time course of serum cardiac troponin T (cTnT) elevations for the early detection of anthracycline cardiotoxicity. cTnT was analyzed serially in 78 patients with hematological malignancies receiving 142 treatment cycles including various anthracyclines. cTnT positivity was defined as an increase in cTnT >or=0.03 ng/ml and was observed in 12 patients (15%) during 16 treatment cycles (11%). Peak cTnT levels were observed on day +21.5 (median, range: day +6 to day +35) after initiation of anthracycline therapy. cTnT positivity lasted >or=3 days in 63% of cycles and began to occur after a median of two anthracycline doses. Follow-up echocardiography in 28 patients showed a greater decrease in left ventricular ejection fraction (LVEF) in cTnT-positive patients compared to the cTnT-negative group (10% vs 2%, p=0.017). Age, gender, and pretreatment LVEF had no influence on the occurrence of cTnT positivity. Serial measurement of serum cTnT reveals delayed subclinical myocardial damage even after minor anthracycline exposure, may identify patients at risk for subsequent myocardial dysfunction, and suggests prolonged damage to the cardiac myofibrillar system.