Early detection of cardiotoxicity during chemotherapy using biomarkers

19521

Cancer chemotherapy (CHEMO), especially anthracycline-containing regimens, may result in heart failure and left ventricular dysfunction (LVD) due to cardiotoxicity (CVTx). The ability to detect CVTx currently utilizes techniques to assess LVD, such as MUGA or echocardiography (Echo), which have substantial limitations and only detect LVD well after it occurs. Cardiac biomarkers, troponin (Trop I) and B-Type Natriuretic Peptide (BNP) are well established for detecting myocardial injury and LVD in patients without cancer. Limited evidence suggests that these may be important predictors of subsequent CVTx during CHEMO, but these markers have not been systematically investigated prospectively. Methods: Patients undergoing anthracycline-containing combination CHEMO were evaluated at baseline with: history and physical; electrocardiogram; Echo; and BNP and Trop I. Biomarkers were repeated before and after up to 6 cycles of CHEMO. ECHO was repeated after 6 cycles or at 6 months from baseline. Cardiac events (heart failure, LVD, sudden death, or arrhythmia) were documented, if present. Results: To date, 111 (53M/58F) patients, age 56±14 (mean±SD), with either lymphoma (n=39, 35%), sarcoma (n=60, 54%), or breast cancer (n=12, 11%) were enrolled. At least one traditional cardiac risk factor was identified in 77 (69%) and 2 or more risk factors noted in 46 (41%). Baseline ECHO parameters including ejection fraction (EF) and biomarkers were normal. With CHEMO, the mean post CHEMO BNP value (pg/ml) for the group did not change significantly; however, in the 8 patients with cardiac events, the BNP post CHEMO was elevated. The Trop I values were not abnormal except in 2 patients with events. Conclusion: Preliminary data collected to date indicates that BNP values during CHEMO remain normal unless cardiac events occur. Additionally, elevated BNP levels appear to detect CVTx, but LVEF did not. Furthermore, patients receiving CHEMO frequently have cardiac risk factors that may promote CVTx.

[Table: see text]

No significant financial relationships to disclose.

Prediction of short-term outcome in terminally ill cancer patients

19572

Background: Oncologists tend to overestimate survival of advanced cancer patients (pts) emphasizing the need for objective prognostic models to prevent futility. Methods: From January 2004 to May 2006, a prospective unicenter study was done in terminally ill cancer pts referred to a palliative care unit. Evaluation at admission included physical examination and the following routine blood tests : total blood count, hemostasis (Prothrombin Time (PT), activated Partial Thromboplastin Time (aPTT)), inflammatory and nutritional proteins (fibrinogen, ferritin, PINI = [alpha-1 acid glycoprotein x C-reactive protein (CRP)] / [albumin x prealbumin]), serum lipids (total and HDL cholesterol), biochemistry (urea, serum creatinine, calcium, total bilirubin, B12 vitamin) and liver enzymes (AST, ALT, LDH). Fatal outcome within the first 48 hours and lack of blood tests were exclusion criteria. A multivariate analysis according to a logistic regression was used to estimate the probability of fatal outcome within 2 weeks (wks) based on baseline patients characteristics. Results: 285 consecutive pts were hospitalized; 246 were evaluable : 133 men and 113 women (median age : 64 years; range: 18–94). Primary tumor was gynecological (18.3%), gastro-intestinal (16.3%), pulmonary (13.4%), hepatic or biliary (13.8%), urological (11.8%), head and neck (9.3%), haematological (3.3%) or others (13.8%). In univariate analysis, survival ≤ 2 wks correlated with male gender (p<0.001), Karnofsky Index (KI) (p<0.001), leucocytes (WBC) (p<0.001), aPTT (p=0.04), Urea (p=0.011), Total bilirubin (p=0.004), AST (p<0.001), LDH (p=0.008), albumin (p=0.042), prealbumin (p=0.004), CRP (p=0.028), ferritin (p=0.007), B12 vitamin (p=0.042) and PINI (p=0.001). In multivariate analysis, male gender (p=0.034), cutaneous metastases (p=0.012), KI ≤ 20% (p=0.002), WBC > 7.5G/l (p=0.012), fibrinogen > 6.5 g/l (p=0.021), LDH > 2N (p=0.035) and PINI > 20 (p=0.007) were predictive. A mathematical model was built to estimate the probability of fatal outcome within 2 wks. Conclusions: We created a tool which may help physicians to better estimate survival of terminally ill cancer pts and to prevent unnecessary overtreatment. Our score needs prospective validation in a multicenter study.

No significant financial relationships to disclose.

Acute heart failure in bone marrow transplantation: Impact of intravenous immune globulin as adjuvant therapy

16512

Background: Little is known regarding management or treatment of cardiac failure after bone marrow transplantation. We investigated the management, treatment and outcome of new onset acute decompensated heart failure (ADHF) after bone marrow transplantation (BMT) with beta blockers, ace-inhibitors and adjuvant intravenous immune globulin (IVIG) therapy. Methods: We retrospectively examined 25 patients with ADHF. Eleven of these patients developed congestive heart failure within 100 days of BMT. Baseline echocardiograms were normal prior to admission and all patients were hospitalized and evaluated for left ventricular ejection fraction (LVEF), and New York Heart Association (NYHA) class. Patients with acute heart failure were treated with standard heart failure medications and patients post-BMT were treated with standard heart failure therapy plus adjuvant (IVIG) (500mg/Kg/day) for 48 hours. Baseline LVEF and NYHA class of 11 patients pre- and post-BMT were compared with LVEF and NYHA class of 14 patients with ADHF that did not receive a BMT. Results: The baseline diagnosis for all patients in the BMT group was NYHA class 4 and post-therapy improved to class 1.2. The baseline diagnosis for all patients in the non-BMT group were NYHA class 3.7 and improved to class 1.2 with medical therapy. The mean LVEF in the BMT group at diagnosis of ADHF was 27.5% and the mean post-therapy with IVIG was 57.6%. The mean baseline LVEF in the group not undergoing BMT and at diagnosis of ADHF was 28.2% and improved post-therapy to 45.2%. Conclusions: Acute decompensated heart failure in the cancer patient is highly treatable with aggressive medical management. Patients with ADHF after BMT and treated with IVIG may have potential clinical benefits with IVIG and standard medical therapy. Significant improvement in LVEF and NYHA were present in the BMT group versus the non-BMT group. These data suggest that BMT outcomes may be improved with routine heart failure management. Further randomized studies should be conducted.

[Table: see text]

No significant financial relationships to disclose.

Comparison of doxorubicin cardiotoxicity in pediatric patients when given with dexrazoxane versus a continuous infusion

9044

Background: Despite the effectiveness of doxorubicin (D) in sarcomas, its use is limited by cardiotoxicity. Both delivery by continuous infusion (CI) and use of the cardioprotectant dexrazoxane (Z) have been used to reduce cardiotoxicity. Since 1998 patients with Ewing’s sarcoma seen at MDACC have been treated with a total of 540 mg/m2 D given with Z (ZD). During this period patients with osteosarcoma have been treated with 360–540 mg/m2 D given as a 48-hour infusion (CID). Methods: To compare the cardiotoxicity of ZD versus CID, we did a retrospective review of patients seen on the pediatric service at MDACC since 1998. Patients included needed to have had 1) planned therapy of at least 360 mg/m2 D, given either as ZD or CID; 2) measurement of ejection fraction (EF) prior to any D; and 3) routine monitoring of cardiotoxicity with EF. Patients were recorded as having cardiotoxicity for any EF<50% or clinical symptoms. Groups were compared by 2-sided t-test and Fisher’s Exact test. Results: A total of 64 patients were treated with ZD or DCI, 52 of which are evaluable. Comparison of ZD to CID showed no significant difference in age or male:female ratio. Total D dose was higher in ZD. Cardiotoxicity was higher in DCI as determined by number of patients with cardiotoxicity and EF on worst Echo. Conclusions: Despite the higher total dose of D, patients treated with ZD had less cardiotoxicity. Whether this is due to giving a cardioprotectant or other factors, such as, higher degree of electrolyte abnormalities or greater degree of anemia in patients treated with CID needs to be investigated.

[Table: see text]

No significant financial relationships to disclose.

Long term cardiac tolerability of trastuzumab in HER-2-overexpressing metastatic breast cancer (MBC)

629

Background: The use of trastuzumab is associated with an increased risk of cardiotoxic events such as congestive hearth failure (CHF) and decline in the left ventricular ejection fraction (LVEF). Our objectives were to evaluate the incidence of cardiac dysfunction, to identify risk factors and to evaluate the outcome of patients with MBC treated with trastuzumab for one year or longer. Methods: Among 218 MBC patients treated with trastuzumab-based therapy for at least one year, 173 patients were evaluable for cardiac toxicity. Cardiac events (CE) were defined as follows: 1) asymptomatic drop of LVEF below 50%; 2) drop of 20 percentage points in LVEF compared to the baseline; 3) signs or symptoms of CHF. The cardiac toxicity was graded according the NCI-CTCAE, version 3.0. Results: Median age at the start of trastuzumab therapy was 50 years (range, 26–79), median cumulative time on trastuzumab was 21.3 months (range, 11.6–77.6), and median follow-up was 32.2 months (range, 9.7–79.0). Eighty-five percent of patients received prior anthracyclines (median cumulative doxorubicin dose: 300 mg/m2). Forty-nine patients (28%) experienced a CE: 3 patients (1.7%) had an asymptomatic drop in the LVEF of 20 percentage points; 27 patients (15.6%) experienced grade 2 cardiac toxicity; and 18 patients (10.4%) experienced grade 3 cardiac toxicity. There was one cardiac related death (0.5%). Cardiac event-free survival was 87.3% at 1 year. All but four patients had improved LVEF or symptoms of CHF after stopping trastuzumab or with appropriate therapy. After complete recovery, 26 patients were re treated with trastuzumab; 16 patients did not experience further CE. Concomitant taxane use was the only factor significantly associated with a CE (HR: 4.37, 95%CI 1.06–17.98, p:0.04).Prior anthracycline exposure was not associated with increased risk of CE. Conclusions: The risk of cardiac toxicity of long-term trastuzumab-based therapy is acceptable in this population, and this toxicity is reversible in the majority of the patients. In patients who have experienced a CE, additional treatment with trastuzumab can be considered after recovery of cardiac function. The increased risk of cardiotoxicity associated with taxane administration needs to be further investigated.

No significant financial relationships to disclose.

Sclérodermie conjugale

INTRODUCTION

Familial occurrence of progressive systemic sclerosis is unusual. The occurrence of conjugal scleroderma is exceptional.

EXEGESIS

We report here a case of systemic sclerosis in a wife and husband who both developed the onset of illness within a 10-year period. Solvent exposure was noted.

CONCLUSION

The etiology of systemic sclerosis remains unknown. Environmental factors may play role in its pathogenesis.

[Vertical superposition on distance radiography in norma lateralis: normal or asymmetrical?]

Cephalometric analysis, together with clinical examination and study of models, is an essential tool in practitioners' preparations of orthodontic diagnoses for their patients. However, despite the use of standardized techniques, cephalograms in norma lateralis still inescapably superimpose patients' right and left sides on each other. This study attempts to demonstrate the significance of these superimpositions particularly when serial cephalograms are themselves superimposed on each other to discern growth or treatment changes.

Immortalized goat milk epithelial cell lines replicate CAEV at high level

Primary milk epithelial cells were isolated from CAEV-uninfected goats and three cell lines designated TIGMEC-1, TIGMEC-2 and TIGMEC-3 were established. The three cell lines retained their morphological characteristics of epithelial cells and expressed specific epithelial cytokeratin marker as well as the immortalizing SV40 large T antigen. The kinetics of growth of TIGMEC1, TIGMEC2 and TIGMEC3 cell lines showed a doubling time of 24-48 hours while the parental cell lines became senescent after the passage 6 in cell culture. Like the parental primary cells, the three cell lines were found to be highly sensitive to CAEV-pBSCA, an infectious molecular clone of CAEV-CO strain, and to a French isolate CAEV-3112. TIGMEC cell lines infected with CAEV-pBSCA became chronically infected producing high virus titers in absence of cytopathic effects. These cell lines may be useful for study of the possible physiological alterations in mammary epithelial cells infected with small ruminant lentiviruses and their consequences on milk quality. On an other hand, these cell lines can be used to study their role in virus transmission and pathogenesis.

Hemodynamic effects of tezosentan, an intravenous dual endothelin receptor antagonist, in patients with class III to IV congestive heart failure

BACKGROUND

Endothelin-1, a powerful mediator of vasoconstriction, is increased in patients with congestive heart failure and appears to be a prognostic marker that strongly is correlated with the severity of disease. However, little is known about the potential immediate beneficial effects of acute blockade of the endothelin system in patients with symptomatic left ventricular dysfunction. We assessed the hemodynamic effects and safety of tezosentan, an intravenous dual endothelin receptor antagonist, in patients with moderate to severe heart failure.

METHODS AND RESULTS

This randomized placebo-controlled study evaluated the hemodynamic effects of 6-hour infusions of tezosentan at 5, 20, 50, and 100 mg/h compared with placebo in 61 patients with New York Heart Association class III to IV heart failure. Plasma endothelin-1 and tezosentan concentrations were also determined. Treatment with tezosentan caused a dose-dependent increase in cardiac index ranging from 24.4% to 49.9% versus 3.0% with placebo. Tezosentan also dose-dependently reduced pulmonary capillary wedge pressure and pulmonary and systemic vascular resistances, with no change in heart rate. No episodes of ventricular tachycardia or hypotension requiring drug termination were observed during tezosentan infusion. Tezosentan administration resulted in dose-related increased plasma endothelin-1 concentrations.

CONCLUSIONS

The present study demonstrated that tezosentan can be safely administered to patients with moderate to severe heart failure and that by virtue of its ability to antagonize the effects of endothelin-1, it induced vasodilatory responses leading to a significant improvement in cardiac index. Further studies are under way to determine the clinical effects of tezosentan in the setting of acute heart failure.

Behavioural, physiological and metabolic responses to long-term starvation and refeeding in a blind cave-dwelling (Proteus anguinus) and a surface-dwelling (Euproctus asper) salamander

The effects of long-term starvation and subsequent refeeding on haematological variables, behaviour, rates of oxygen consumption and intermediary and energy metabolism were studied in morphologically similar surface- and cave-dwelling salamanders. To provide a hypothetical general model representing the responses of amphibians to food stress, a sequential energy strategy has been proposed, suggesting that four successive phases (termed stress, transition, adaptation and recovery) can be distinguished. The metabolic response to prolonged food deprivation was monophasic in the epigean Euproctus asper (Salamandridae), showing an immediate, linear and large decrease in all the energy reserves. In contrast, the hypogean Proteus anguinus (Proteidae) displayed successive periods of glucidic, lipidic and finally lipido-proteic-dominant catabolism during the course of food deprivation. The remarkable resistance to long-term fasting and the very quick recovery from nutritional stress of this cave organism may be explained partly by its ability to remain in an extremely prolonged state of protein sparing and temporary torpor. Proteus anguinus had reduced metabolic and activity rates (considerably lower than those of most surface-dwelling amphibians). These results are interpreted as adaptations to a subterranean existence in which poor and discontinuous food supplies and/or intermittent hypoxia may occur for long periods. Therefore, P. anguinus appears to be a good example of a low-energy-system vertebrate.

Gene flow in a facultative apomictic poacea, the savanna grass Hyparrhenia diplandra

The genetics of the poacea Hyparrhenia diplandra was studied in four natural populations from an ecological station in West Africa, where it makes up 80% of grasses from wet savanna and constitutes a dense continuum of randomly distributed individuals. DNA content and cytogenetical observations suggest it is an allotetraploid. Using two highly variable microsatellites (heterozygosity H = 0.615-0.616), we show that this species is an apomict with rare sexual reproduction events that account for approximately 0.5% of seeds pollinated in the wild. Hexaploid individuals were also produced, corroborating the observation of aberrant genotypes in the wild. The spatial extent of asexual clones in the field was low in comparison with the predominance of apomixis, thus indicating a low dispersal of seeds from their parent. Heterozygosity and departure from Hardy-Weinberg predictions were similar in the four populations, revealing a high apparent selfing rate s = 0.599 among sexually produced seeds. This is an overestimate since we could not distinguish true selfing from reciprocal outcrosses between neighboring individuals from the same apomictic clone. Gene flow by pollen could be substantial, possibly explaining the absence of isolation by distance in the studied area.

AMPA receptor antagonists, GYKI 52466 and NBQX, do not block the induction of long-term potentiation at therapeutically relevant concentrations

The involvement of alpha-amino-3-hydroxy-5-methylizoxazole-4-propionic acid (AMPA) receptors in induction of long-term potentiation (LTP) was examined in rat hippocampal slice preparation. Using conventional extracellular recording, excitatory postsynaptic potentials (EPSPs) and population action potentials (PSs), evoked by low-frequency stimulation of the Schaffer collateral-commissural fibres, were recorded in the CA1 region. The effects of a competitive AMPA receptor antagonist, 6-nitro-7-sulfamoylbenzo(f)quinoxaline-2, 3-dione (NBQX), and that of a non-competitive blocker, 1-(4-aminophenyl)-4-methyl-7,8-methylendioxy-5H-2,3-benzodiazepine (GYKI 52466) have been examined. 0.25-0.5 microM of NBQX and 20-40 microM of GYKI 52466 did not suppress the induction of LTP. LTP was attenuated only at the highest concentrations tested (1 microM NBQX or 80 microM GYKI 52466). These in vitro concentrations, however, exceed the brain levels needed for in vivo anticonvulsant action. Furthermore, even at the highest concentrations both compounds suppressed only the expression but not the induction of LTP. Namely after their washout LTP reappeared. Thus, at pharmacologically relevant concentrations these AMPA receptor antagonists apparently do not suppress LTP, a cellular mechanism underlying memory formation. These experiments suggest that in clinical practice AMPA receptor blockade may have some advantage over N-methyl-D-aspartate receptor antagonism, which is accompanied by severe memory impairment.

Confocal imaging of N-methyl-D-aspartate receptors in living cortical neurons

The fluorescence-conjugated N-methyl-D-aspartate receptor-selective antagonist, BODIPY-conantokin-G, was employed to label N-methyl-D-aspartate receptors in living neurons derived from the visual cortex of embryonic rats. The fluorescent labeling was visualized and analysed using confocal microscopy and digital imaging techniques. BODIPY-conantokin-G binding sites were homogeneously distributed across somata four days after neurons (E17-20) were placed in culture. In five-day-old cultures, BODIPY-conantokin-G binding sites became clusters of fluorescently labeled spots which were arranged irregularly on somata and proximal neurites. Distal neurites displayed fluorescent labeling after 10-15 days in culture. Displacement experiments showed that spermine and unlabeled conantokin-G compete with BODIPY-conantokin-G labeling at the N-methyl-D-aspartate receptor-associated polyamine site. The N-methyl-D-aspartate receptor antagonist 2-amino-5-phosphonovaleric acid also depressed the labeling but with a weaker effect, probably due to interactions occurring between the N-methyl-D-aspartate receptor agonist binding site and the polyamine modulatory site. The fluorescent dyes FM 1-43 and FM 4-64 were used in double-labeling studies to compare the distribution of nerve terminals with that of BODIPY-conantokin-G binding sites. BODIPY-conantokin-G binding clusters were associated with presynaptic nerve terminals while isolated BODIPY-conantokin-G binding sites were not always opposed to terminals. The aggregation of receptors to form clusters may lead to the functional formation of excitatory synapses. To investigate whether modulation of membrane potentials affected the formation of N-methyl-D-aspartate receptor clusters, cultured neurons were chronically treated for a week with either tetrodotoxin (to block membrane action potentials) or a high concentration of potassium to depolarize the membrane. While neurons in the tetrodotoxin-treated group showed a similar number of fluorescently labeled clusters compared with the control group, neurons in the high potassium group exhibited a higher number of fluorescently labeled receptor clusters. These results suggest that more active neurons may tend to form more N-methyl-D-aspartate synapses during early development.

Estrogen-induced vasoprotection is estrogen receptor dependent: evidence from the balloon-injured rat carotid artery model

BACKGROUND

Previous studies have shown that estrogen (E2) is vasoprotective in multiple animal models of vascular injury, including mice with homologous disruptions of either the alpha or beta isoforms of the estrogen receptor (ER) gene, calling into question the ER dependency of the vasoprotective effect. This study used ICI 182,780, a nonselective ER antagonist, to test the hypothesis that the vasoprotective effect of E2 in the rat carotid injury model is ER mediated.

METHODS AND RESULTS

Intact female Sprague-Dawley rats were divided into 4 groups and treated with the nonselective ER antagonist ICI 182,780 (ICI; 0.5, 1.5, or 5 mg. kg(-1). d(-1), subcutaneously [S.C.]) or vehicle, beginning before balloon injury of the right common carotid artery and continuing for 14 days afterward. Four groups of ovariectomized rats (OVX) were treated with 17beta estradiol (E2) (20 microgram. kg(-1). d(-1), S.C.) alone or combined with ICI 5 mg. kg(-1). d(-1), S.C.; with ICI 5 mg. kg(-1). d(-1) alone; or with vehicle according to a similar protocol. Two weeks after injury, rats were killed, and the carotid arteries were evaluated for neointima formation using morphometric analysis. ICI 182,780 blunted the E2-related protective effect and increased neointima formation in injured carotid arteries of intact female rats in a dose-dependent fashion. ICI had no effect on neointima formation in OVX, but addition of ICI to E2 in OVX blocked the inhibitory effect of exogenous E2 on neointima formation.

CONCLUSIONS

These results indicate that the vasoprotective effect of E2 in the balloon-injured rat carotid artery model is mediated by ER.

Blocking the trigeminal EPSP in rat abducens motoneurons in vivo with the AMPA antagonists NBQX and GYKI 53655

In pentobarbitone-anaesthetized rats, the effects of two AMPA receptor antagonists, the competitive antagonist 2, 3-dihydroxy-6-nitro-7-sulfamoyl-benzo-(F)-quinoxaline (NBQX) and the non-competitive 2,3-benzodiazepine GYKI 53655, were compared on excitatory synaptic transmission of trigeminal origin in intracellularly-recorded abducens motoneurons. The effects of both antagonists were also investigated on the alpha-amino-3-hydroxy-5-methyl isoxazole-4-propionic acid (AMPA)-, kainate-, and N-methyl-D-aspartate (NMDA)-induced depression of extracellular antidromic field potentials in the abducens motor nucleus. Microiontophoretic application (< or =100 nA) or intravenous injection of NBQX (< or =5 mg/kg) affected both AMPA- and kainate-induced depressions whereas GYKI 53655 (< or =100 nA; < or =4 mg/kg) blocked only the AMPA-induced depression. Neither NBQX or GYKI 53655 affected NMDA-induced depressions of antidromic field potentials. Using low intravenous (i.v.) doses of the antagonists NBQX or GYKI 53655 (2-2.5 mg/kg), a complete blockade of the composite disynaptic trigeminal excitatory post-synaptic potential (EPSP) was obtained without any changes in membrane potential, input resistance and antidromic action potentials in abducens motoneurons. GYKI 53655 was more potent at low i.v. doses (0.5-1.8 mg/kg) but NBQX had longer-lasting effects. The results show the existence of differences between the blocking action of NBQX and GYKI 53655 on AMPA-mediated receptor EPSP in abducens motoneurons.