Congenital heart defects caused by FOXJ1.

FOXJ1 is expressed in ciliated cells of the airways, testis, oviduct, central nervous system and the embryonic left-right organizer. Ablation or targeted mutation of Foxj1 in mice, zebrafish and frogs results in loss of ciliary motility and/or reduced length and number of motile cilia, affecting the establishment of the left-right axis. In humans, heterozygous pathogenic variants in FOXJ1 cause ciliopathy leading to situs inversus, obstructive hydrocephalus and chronic airway disease. Here, we report a novel truncating FOXJ1 variant (c.784_799dup; p.Glu267Glyfs*12) identified by clinical exome sequencing from a patient with isolated congenital heart defects (CHD) which included atrial and ventricular septal defects, double outlet right ventricle (DORV) and transposition of the great arteries. Functional experiments show that FOXJ1 c.784_799dup; p.Glu267Glyfs*12, unlike FOXJ1, fails to induce ectopic cilia in frog epidermis in vivo or to activate the ADGB promoter, a downstream target of FOXJ1 in cilia, in transactivation assays in vitro. Variant analysis of patients with heterotaxy or heterotaxy-related CHD indicates that pathogenic variants in FOXJ1 are an infrequent cause of heterotaxy. Finally, we characterize embryonic-stage CHD in Foxj1 loss-of-function mice, demonstrating randomized heart looping. Abnormal heart looping includes reversed looping (dextrocardia), ventral looping and no looping/single ventricle hearts. Complex CHDs revealed by histological analysis include atrioventricular septal defects, DORV, single ventricle defects as well as abnormal position of the great arteries. These results indicate that pathogenic variants in FOXJ1 can cause isolated CHD.

Dnmt3a deficiency in the skin causes focal, canonical DNA hypomethylation and a cellular proliferation phenotype.

DNA hypomethylation is a feature of epidermal cells from aged and sun-exposed skin, but the mechanisms responsible for this methylation loss are not known. Dnmt3a is the dominant de novo DNA methyltransferase in the skin; while epidermal Dnmt3a deficiency creates a premalignant state in which keratinocytes are more easily transformed by topical mutagens, the conditions responsible for this increased susceptibility to transformation are not well understood. Using whole genome bisulfite sequencing, we identified a focal, canonical DNA hypomethylation phenotype in the epidermal cells of Dnmt3a-deficient mice. Single-cell transcriptomic analysis revealed an increased proportion of cells with a proliferative gene expression signature, while other populations in the skin were relatively unchanged. Although total DNMT3A deficiency has not been described in human disease states, rare patients with an overgrowth syndrome associated with behavioral abnormalities and an increased risk of cancer often have heterozygous, germline mutations in DNMT3A that reduce its function (Tatton-Brown Rahman syndrome [TBRS]). We evaluated the DNA methylation phenotype of the skin from a TBRS patient with a germline DNMT3AR882H mutation, which encodes a dominant-negative protein that reduces its methyltransferase function by ∼80%. We detected a focal, canonical hypomethylation phenotype that revealed considerable overlap with hypomethylated regions found in Dnmt3a-deficient mouse skin. Together, these data suggest that DNMT3A loss creates a premalignant epigenetic state associated with a hyperproliferative phenotype in the skin and further suggest that DNMT3A acts as a tumor suppressor in the skin.

Remethylation of Dnmt3a-/- hematopoietic cells is associated with partial correction of gene dysregulation and reduced myeloid skewing.

Mutations in the DNA methyltransferase 3A (DNMT3A) gene are the most common cause of age-related clonal hematopoiesis (ARCH) in older individuals, and are among the most common initiating events for acute myeloid leukemia (AML). The most frequent DNMT3A mutation in AML patients (R882H) encodes a dominant-negative protein that reduces methyltransferase activity by ∼80% in cells with heterozygous mutations, causing a focal, canonical DNA hypomethylation phenotype; this phenotype is partially recapitulated in murine Dnmt3a-/- bone marrow cells. To determine whether the hypomethylation phenotype of Dnmt3a-/- hematopoietic cells is reversible, we developed an inducible transgene to restore expression of DNMT3A in transplanted bone marrow cells from Dnmt3a-/- mice. Partial remethylation was detected within 1 wk, but near-complete remethylation required 6 mo. Remethylation was accurate, dynamic, and highly ordered, suggesting that differentially methylated regions have unique properties that may be relevant for their functions. Importantly, 22 wk of DNMT3A addback partially corrected dysregulated gene expression, and mitigated the expansion of myeloid cells. These data show that restoring DNMT3A expression can alter the epigenetic "state" created by loss of Dnmt3a activity; this genetic proof-of-concept experiment suggests that this approach could be relevant for patients with ARCH or AML caused by loss-of-function DNMT3A mutations.

Genetic Variants Associated With Cancer Therapy-Induced Cardiomyopathy.

BACKGROUND: Cancer therapy-induced cardiomyopathy (CCM) is associated with cumulative drug exposures and preexisting cardiovascular disorders. These parameters incompletely account for substantial interindividual susceptibility to CCM. We hypothesized that rare variants in cardiomyopathy genes contribute to CCM. METHODS: We studied 213 patients with CCM from 3 cohorts: retrospectively recruited adults with diverse cancers (n=99), prospectively phenotyped adults with breast cancer (n=73), and prospectively phenotyped children with acute myeloid leukemia (n=41). Cardiomyopathy genes, including 9 prespecified genes, were sequenced. The prevalence of rare variants was compared between CCM cohorts and The Cancer Genome Atlas participants (n=2053), healthy volunteers (n=445), and an ancestry-matched reference population. Clinical characteristics and outcomes were assessed and stratified by genotypes. A prevalent CCM genotype was modeled in anthracycline-treated mice. RESULTS: CCM was diagnosed 0.4 to 9 years after chemotherapy; 90% of these patients received anthracyclines. Adult patients with CCM had cardiovascular risk factors similar to the US population. Among 9 prioritized genes, patients with CCM had more rare protein-altering variants than comparative cohorts ( P≤1.98e-04). Titin-truncating variants (TTNtvs) predominated, occurring in 7.5% of patients with CCM versus 1.1% of The Cancer Genome Atlas participants ( P=7.36e-08), 0.7% of healthy volunteers ( P=3.42e-06), and 0.6% of the reference population ( P=5.87e-14). Adult patients who had CCM with TTNtvs experienced more heart failure and atrial fibrillation ( P=0.003) and impaired myocardial recovery ( P=0.03) than those without. Consistent with human data, anthracycline-treated TTNtv mice and isolated TTNtv cardiomyocytes showed sustained contractile dysfunction unlike wild-type ( P=0.0004 and P<0.002, respectively). CONCLUSIONS: Unrecognized rare variants in cardiomyopathy-associated genes, particularly TTNtvs, increased the risk for CCM in children and adults, and adverse cardiac events in adults. Genotype, along with cumulative chemotherapy dosage and traditional cardiovascular risk factors, improves the identification of patients who have cancer at highest risk for CCM. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifiers: NCT01173341; AAML1031; NCT01371981.

Detailed phenotyping reveals distinct trajectories of cardiovascular function and symptoms with exposure to modern breast cancer therapy.

BACKGROUND: Breast cancer therapies are associated with a risk of cardiac dysfunction, most commonly defined by changes in left ventricular ejection fraction (LVEF). Recently, the authors identified 3 classes of LVEF change after exposure to anthracyclines and/or trastuzumab using latent class growth modeling. The objective of the current study was to characterize the clinical, biochemical, and functional profiles associated with LVEF trajectory class membership. METHODS: Transthoracic echocardiography and biomarker assessments were performed and questionnaires were administered at standardized intervals in a longitudinal cohort of 314 patients with breast cancer who were treated with anthracyclines and/or trastuzumab. Univariable and multivariable multinomial regression analyses evaluated associations between baseline variables and LVEF trajectory class membership. Generalized estimating equations were used to define mean changes in cardiovascular measures over time within each class. RESULTS: Among the 3 distinct subgroups of LVEF changes identified (stable [class 1]; modest, persistent decline [class 2]; and significant early decline followed by partial recovery [class 3]), higher baseline LVEF, radiotherapy, and sequential therapy with anthracyclines and/or trastuzumab were associated with class 2 or 3 membership. Sustained abnormalities in longitudinal strain and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were observed in patients in class 2, as were heart failure symptoms. Similar abnormalities were observed in patients in class 3, but there was a trend toward recovery, particularly for longitudinal strain. CONCLUSIONS: Patients with modest, persistent LVEF declines experienced sustained abnormalities in imaging and biochemical markers of cardiac function and heart failure symptoms. Further investigation is needed to characterize the long-term risk of heart failure, particularly in those with modest LVEF declines.

A cross-sectional study of environmental, dog, and human-related risk factors for positive canine leptospirosis PCR test results in the United States, 2009 to 2016.

BACKGROUND: Canine leptospirosis is a reemerging zoonotic disease concern in North America, and a better understanding of its epidemiology is needed. Wide-scale use and subsequent analyses of polymerase chain reaction (PCR) testing may provide additional insight into leptospirosis. This study aimed to describe temporal trends, to descriptively map, and to identify environmental, dog, and human-level factors associated with positive canine leptospirosis PCR test results in the United States. RESULTS: Data obtained from IDEXX Laboratories, Inc. on 40,118 canine leptospirosis PCR tests run in the United States between 2009 and 2016 were evaluated. Climate and socioeconomic (e.g. urban influence, income) data were obtained from public databases. Choropleth maps were created to identify high test-positive proportion areas and a cross-sectional analysis was completed with generalized (univariable, followed by multivariable) mixed logistic regression models accounting for county within state to identify significant predictors for a positive test. Overall test-positive proportion was 5.4% across the United States, with the regional point estimate highest in the southwest (8.1%). In the final multivariable model, the odds of a positive test were greater for male dogs (Odds Ratio [OR] = 1.28) and dogs 0-4 years of age (ORs ranged from 0.35-0.71 for the other age groups). The odds of a positive test were greater for dogs living in areas with wet environmental conditions (OR = 1.24). Season and temperature, as well as the interaction between them, were significant predictors of a positive test. Dogs had a greater probability of testing positive during cool temperatures (< 4 °C) compared to the other temperature categories in the fall season. CONCLUSIONS: These findings based on PCR testing allow for an improved understanding of factors influencing a positive canine leptospirosis PCR test and will assist targeted education and prevention efforts.

Detailed Echocardiographic Phenotyping in Breast Cancer Patients: Associations With Ejection Fraction Decline, Recovery, and Heart Failure Symptoms Over 3 Years of Follow-Up.

BACKGROUND: Cardiovascular disease in patients with breast cancer is of growing concern. The longitudinal effects of commonly used therapies, including doxorubicin and trastuzumab, on cardiac remodeling and function remain unknown in this population. We aimed to define the changes in echocardiographic parameters of structure, function, and ventricular-arterial coupling, and their associations with left ventricular ejection fraction (LVEF) and heart failure symptoms. METHODS: In a longitudinal prospective cohort study of 277 breast cancer participants receiving doxorubicin (Dox), trastuzumab (Tras), or both (Dox+Tras), we obtained 1249 echocardiograms over a median follow-up of 2.0 (interquartile range, 1.0-3.0) years. Left ventricular structure, diastolic and contractile function, and ventricular-arterial coupling measures were quantified in a core laboratory blinded to participant characteristics. We evaluated changes in echocardiographic parameters over time, and used repeated-measures regression models to define their association with LVEF decline and recovery. Linear regression models defined the association between early changes in these parameters and subsequent changes in LVEF and heart failure symptoms. RESULTS: Overall, 177 (64%) received Dox, 51 (18%) received Tras, and 49 (18%) received Dox+Tras. With Dox, there was a sustained, modest decrease in LVEF over the follow-up duration (1-year change in LVEF -3.6%; 95% confidence interval [CI], -4.4% to -2.8%; 3-year change -3.8%; 95% CI, -5.1% to -2.5%). With Tras, a similar LVEF decline was observed at 1 year (-4.5%; 95% CI, -6.0% to -2.9%) and 3 years (-2.8%; 95%CI, -5.3 to -0.4%). Participants receiving Dox+Tras demonstrated the greatest declines at 1 year (-6.6%; 95% CI, -8.2 to -5.0%), with partial recovery at 3 years (-2.8%; 95% CI, -4.8 to -0.8%). LVEF declines and recovery were associated primarily with changes in systolic volumes, longitudinal and circumferential strain, and ventricular-arterial coupling indices, effective arterial elastance (Ea) and the coupling ratio Ea/Eessb, without evidence for effect modification across therapies. Early changes in volumes, strain, and Ea/Eessb at 4 to 6 months were associated with 1- and 2-year LVEF changes. Similarly, early changes in strain and Ea were associated with worsening heart failure symptoms at 1 year. CONCLUSIONS: Doxorubicin and trastuzumab resulted in modest, persistent declines in LVEF at 3 years. Changes in volumes, strain, and ventricular-arterial coupling were consistently associated with concurrent and subsequent LVEF declines and recovery across therapies.

Impact of Atrial Fibrillation on Heart Failure in Patients Treated With Anthracycline Chemotherapy.

Atrial fibrillation (AF) and anthracyclines are known risk factors for heart failure (HF). The magnitude of the effect of preexisting AF (preanthracycline AF) and newly developed AF (postanthracycline AF) in patients treated with anthracyclines on the occurrence of HF is unknown. The aim of our study was to characterize the impact of preanthracycline and postanthracycline AF on the subsequent occurrence of HF in patients treated with anthracyclines. In 5,598 patients treated with new anthracycline therapy at a tertiary center between 2008 and 2021, propensity score matching was used to match 204 pairs with or without preanthracycline AF and 135 pairs with or without postanthracycline AF. The primary outcome was new-onset symptomatic HF defined by the American Heart Association/American College of Cardiology guidelines. Patients with and without preanthracycline and postanthracycline AF were well matched for age, gender, medications, and cardiovascular risk factors. A total of 45 patients with preanthracycline AF and 23 matched patients developed HF (5-year cumulative incidence: 29% in the preanthracycline AF group and 13% in the matched group, p = 0.003; hazard ratio 2.1, 95% confidence interval 1.3 to 3.4, p = 0.004). A total of 161 patients (2.9%) developed postanthracycline AF. A total of 39 patients (5-year cumulative incidence: 40%) with postanthracycline AF and 9 matched patients (5-year cumulative incidence: 7%) developed HF (hazard ratio 6.1, 95% confidence interval 3.0 to 12.4, p <0.001). Preanthracycline AF and postanthracycline AF are associated with a high incidence of subsequent HF in patients treated with anthracyclines. Prospective studies of therapies are required to decrease HF in these high-risk patients.

Rapid and accurate remethylation of DNA in Dnmt3a-deficient hematopoietic cells with restoration of DNMT3A activity.

Here, we characterize the DNA methylation phenotypes of bone marrow cells from mice with hematopoietic deficiency of Dnmt3a or Dnmt3b (or both enzymes) or expressing the dominant-negative Dnmt3aR878H mutation [R882H in humans; the most common DNMT3A mutation found in acute myeloid leukemia (AML)]. Using these cells as substrates, we defined DNA remethylation after overexpressing wild-type (WT) DNMT3A1, DNMT3B1, DNMT3B3 (an inactive splice isoform of DNMT3B), or DNMT3L (a catalytically inactive "chaperone" for DNMT3A and DNMT3B in early embryogenesis). Overexpression of DNMT3A for 2 weeks reverses the hypomethylation phenotype of Dnmt3a-deficient cells or cells expressing the R878H mutation. Overexpression of DNMT3L (which is minimally expressed in AML cells) also corrects the hypomethylation phenotype of Dnmt3aR878H/+ marrow, probably by augmenting the activity of WT DNMT3A encoded by the residual WT allele. DNMT3L reactivation may represent a previously unidentified approach for restoring DNMT3A activity in hematopoietic cells with reduced DNMT3A function.

Cardiotoxicity of CPX-351 in children and adolescents with relapsed AML: a Children's Oncology Group report.

Introduction: Anthracyclines are effective in treating acute myeloid leukemia (AML) but limited by cardiotoxicity. CPX-351, a liposomal daunorubicin and cytarabine, may provide therapeutic benefit with less cardiotoxicity. Acute changes in left ventricular systolic function and cardiac biomarkers were evaluated after a cycle of CPX-351 in children with relapsed AML treated on the phase 1/2 Children's Oncology Group study, AAML1421. Methods: Subjects received 135 units/m2/dose of CPX-351 on days 1, 3, and 5 as cycle 1. Echocardiograms were performed and centrally quantitated at baseline and at the end of cycle 1 (day 29 +/- 1 week). High sensitivity troponin (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured at baseline and serially through the end of cycle 1 (days 5, 8, 15, 22 and 29). Differences between baseline and post-CPX-351 echo/biomarker measures were analyzed using Wilcoxon signed rank tests. Linear regression was used to model post-CPX-351 left ventricular ejection fraction (LVEF) with cTnT/NT-proBNP at each time point, controlling for baseline LVEF. Cancer therapy related cardiac dysfunction (CTRCD) was defined as a decline in LVEF of ≥10%-<50%. Results: Twenty-five of 38 heavily anthracycline pre-treated (median 348 mg/m2 daunorubicin equivalents) subjects enrolled on AAML1421 were included in the cardiac analyses. At baseline, centrally quantitated LVEF was <50% in 8 of 25 subjects (32%) with a median LVEF of 53.8% [48.0, 56.9]. Following CPX-351, LVEF declined significantly (ΔLVEF -3.3% [-7.8, 0]) and 6 of 25 subjects (24%) experienced CTRCD. Amongst all subjects, hs-cTnT was modestly increased at end of cycle 1 compared to baseline [baseline hs-cTnT 7.2 (3, 10.6); ΔcTnT 1.80 (0, 6.1), p = 0.03]. NT-proBNP remained stably elevated without significant change. No significant associations were seen between NT-proBNP or cTnT levels and post-CPX-351 LVEF. Discussion: In this single arm study of anthracycline pre-treated children exposed to CPX-351, baseline abnormalities in cardiovascular function were prevalent. Following CPX-351, LVEF decreased, cTnT increased, and NT-proBNP did not change. Longer follow-up is needed to determine whether these changes result in clinically meaningful long-term decrements in cardiac function. An ongoing randomized trial of CPX-351 compared to standard anthracyclines in anthracycline naïve patients will provide further insight into the cardiac effects of CPX-351 (ClinicalTrials.gov; NCT04293562).

Statins Do Not Significantly Affect Oxidative Nitrosative Stress Biomarkers in the PREVENT Randomized Clinical Trial.

PURPOSE: Preventing Anthracycline Cardiovascular Toxicity with Statins (PREVENT; NCT01988571) randomized patients with breast cancer or lymphoma receiving anthracyclines to atorvastatin 40 mg daily or placebo. We evaluated the effects of atorvastatin on oxidative and nitrosative stress biomarkers, and explored whether these biomarkers could explain the lack of effect of atorvastatin on LVEF (left ventricular ejection fraction) in PREVENT. PATIENTS AND METHODS: Blood samples were collected and cardiac MRI was performed before doxorubicin initiation and at 6 and 24 months. Thirteen biomarkers [arginine-nitric oxide metabolites, paraoxonase-1 (PON-1) activity, and myeloperoxidase] were measured. Dimensionality reduction using principal component analysis was used to define biomarker clusters. Linear mixed-effects models determined the changes in biomarkers over time according to treatment group. Mediation analysis determined whether biomarker clusters explained the lack of effect of atorvastatin on LVEF. RESULTS: Among 202 participants with available biomarkers, median age was 53 years; 86.6% had breast cancer; median LVEF was 62%. Cluster 1 levels, reflecting arginine methylation metabolites, were lower over time with atorvastatin, although this was not statistically significant (P = 0.081); Cluster 2 levels, reflecting PON-1 activity, were significantly lower with atorvastatin (P = 0.024). There were no significant changes in other biomarker clusters (P > 0.05). Biomarker clusters did not mediate an effect of atorvastatin on LVEF (P > 0.05). CONCLUSIONS: Atorvastatin demonstrated very modest effects on oxidative/nitrosative stress biomarkers in this low cardiovascular risk population. Our findings provide potential mechanistic insight into the lack of effect of atorvastatin on LVEF in the PREVENT trial.

Disruption of FBN1 by an Alu element insertion: A novel genetic cause of Marfan syndrome.

Alu elements are retrotransposons with ubiquitous presence in the human genome that have contributed to human genomic diversity and health. These approximately 300-bp sequences can cause or mediate disease by disrupting coding/splicing regions in the germline, by insertional mutagenesis in somatic cells, and in promoting formation of copy-number variants. Alu elements may also disrupt epigenetic regulation by affecting non-coding regulatory regions. There are increasing reports of apparently sporadic and inherited genetic disorders caused by Alu-related gene disruption, but Marfan syndrome resulting from Alu element insertion has not been previously described. We report a family with classic features of Marfan syndrome whose previous FBN1 genetic testing was inconclusive. Using contemporary next-generation sequencing and bioinformatics analysis, a pathogenic/disruptive Alu insertion occurring in the coding region of the FBN1 gene was identified (c.6564_6565insAlu; p. Glu2189fs) and was confirmed and specified further with Sanger sequencing. This identified the molecular basis of disease in the family that was missed using previous genetic testing technologies and highlights a novel pathogenic mechanism for Marfan syndrome. This case adds to the growing literature of Mendelian diseases caused by Alu retrotransposition, and it also shows the growing capability of genomic technologies for detecting atypical mutation events.

The Association of Metformin With Heart Failure in Patients With Diabetes Mellitus Receiving Anthracycline Chemotherapy.

Background: The prevention of heart failure (HF) is an important issue in patients treated with anthracyclines. Metformin, widely used to treat diabetes mellitus (DM), protects from anthracycline-induced cardiotoxicity in vitro and in animal models. Objectives: The aim of our study was to test the association of metformin with the occurrence of symptomatic HF in patients with DM receiving anthracyclines. Methods: A total of 561 patients with DM received new anthracycline therapy between 2008 and 2021 in a tertiary care center; propensity score matching was used to compare patients with or without metformin treatment. The primary outcome was new onset symptomatic HF occurring within 1 year of the initiation of anthracyclines. Results: A total of 315 patients (65 ± 11 years of age, 33.7% male) were included. Patients with and without metformin were well matched for age, sex, type of cancer, medications, and cardiovascular risk factors. Six patients treated with metformin and 17 matched patients developed HF within 1 year of anthracycline initiation. The incidence of HF in patients treated with metformin was lower than patients without metformin within 1 year after anthracyclines (cumulative incidence: 3.6% vs 10.5%; P = 0.022; HR: 0.35; 95% CI: 0.14-0.90; P = 0.029). The use of metformin (HR: 0.71; 95% CI: 0.50-1.00; P = 0.049), was also associated with lower mortality. Conclusions: The use of metformin was associated with a lower incidence of HF and overall mortality in patients with DM receiving anthracyclines. Our findings should be further confirmed by randomized control trials.

Incidence of MACE in Patients Treated With CAR-T Cell Therapy: A Prospective Study.

Background: Previous retrospective studies have shown that chimeric antigen receptor T (CAR-T) cell therapy may be associated with major adverse cardiovascular events (MACE), especially in the context of cytokine-release syndrome (CRS) events. Objectives: The aim of this prospective observational study was to define the occurrence of MACE in adults undergoing treatment with CAR-T cell therapy and identify associated risk factors. Methods: Vital signs, blood samples, and an echocardiogram were collected prior to and 2 days, 1 week, 1 month, and 6 months after CAR-T cell infusion, and charts were consulted at 12 months. In the event of CRS, echocardiography was repeated within 72 hours. MACE were defined as cardiovascular death, symptomatic heart failure, acute coronary syndrome, ischemic stroke, and de novo cardiac arrhythmia. Results: A total of 44 patients were enrolled (mean age 58 ± 11 years, 77% men). The median follow-up duration was 487 days (Q1-Q3: 258-622 days). There were 24 episodes of CRS in 23 patients (52%) (13 grade 1, 10 grade 2, and 1 grade 3), with a median time to CRS of 4 days. Two patients had MACE (heart failure with preserved ejection fraction and atrial fibrillation) within 1 year and 6 and 7 days after CAR-T cell infusion. There was no change in left ventricular ejection fraction, but a modest decrease in global longitudinal strain was noted. Conclusions: There were few cardiac effects associated with contemporary CAR-T cell therapy. As MACE occurred after CRS episodes, aggressive treatment and close follow-up during CRS events are essential.

Rationale and design of the Children's Oncology Group study AAML1831 integrated cardiac substudies in pediatric acute myeloid leukemia therapy.

Background: Pediatric acute myeloid leukemia (AML) therapy is associated with substantial short- and long-term treatment-related cardiotoxicity mainly due to high-dose anthracycline exposure. Early left ventricular systolic dysfunction (LVSD) compromises anthracycline delivery and is associated with inferior event-free and overall survival in de novo pediatric AML. Thus, effective cardioprotective strategies and cardiotoxicity risk predictors are critical to optimize cancer therapy delivery and enable early interventions to prevent progressive LVSD. While dexrazoxane-based cardioprotection reduces short-term cardiotoxicity without compromising cancer survival, liposomal anthracycline formulations have the potential to mitigate cardiotoxicity while improving antitumor efficacy. This overview summarizes the rationale and methodology of cardiac substudies within AAML1831, a randomized Children's Oncology Group Phase 3 study of CPX-351, a liposomal formulation of daunorubicin and cytarabine, in comparison with standard daunorubicin/cytarabine with dexrazoxane in the treatment of de novo pediatric AML. Methods/design: Children (age <22 years) with newly diagnosed AML were enrolled and randomized to CPX-351-containing induction 1 and 2 (Arm A) or standard daunorubicin and dexrazoxane-containing induction (Arm B). Embedded cardiac correlative studies aim to compare the efficacy of this liposomal anthracycline formulation to dexrazoxane for primary prevention of cardiotoxicity by detailed core lab analysis of standardized echocardiograms and serial cardiac biomarkers throughout AML therapy and in follow-up. In addition, AAML1831 will assess the ability of early changes in sensitive echo indices (e.g., global longitudinal strain) and cardiac biomarkers (e.g., troponin and natriuretic peptides) to predict subsequent LVSD. Finally, AAML1831 establishes expert consensus-based strategies in cardiac monitoring and anthracycline dose modification to balance the potentially competing priorities of cardiotoxicity reduction with optimal leukemia therapy. Discussion: This study will inform diagnostic, prognostic, preventative, and treatment strategies regarding cardiotoxicity during pediatric AML therapy. Together, these measures have the potential to improve leukemia-free and overall survival and long-term cardiovascular health in children with AML. Clinical trial registration: https://clinicaltrials.gov/, identifier NCT04293562.

Potential Drivers for the Re-Emergence of Canine Leptospirosis in the United States and Canada.

Canine leptospirosis is an important zoonotic disease in many countries. This review examines potential drivers for increased diagnoses of canine leptospirosis in the United States and Canada, using the epidemiologic triad of agent-environment-host as a template. Leptospira spp. are classified into more than 250 serovars, but in many laboratories only 6 are routinely tested for in serologic agglutination tests of canine sera. Leptospiral infections in dogs may potentially go undetected with unemployed or currently employed diagnostic methods. Disease transmission from infected reservoir hosts usually occurs via urine-contaminated environmental sources such as water. Direct contact between infected and susceptible individuals, environmental factors such as climate changes in temperature and/or rainfall, and increasing number and urbanization of reservoir hosts may greatly increase dog exposure risks. A dog's lifestyle may influence exposure risk to leptospirosis, but vaccination based on proper identification of circulating serogroups dramatically reduces post-exposure infections. Regrettably, resistance to vaccination by veterinarians and dog owners leaves a large number of dogs at risk for this zoonotic disease.

Canine leptospirosis in Canada, test-positive proportion and risk factors (2009 to 2018): A cross-sectional study.

Over the past decade, there has been an apparent increased frequency and widened distribution of canine leptospirosis in Canada, however, this has been minimally investigated. Availability and clinical uptake of Leptospira polymerase chain reaction (PCR)-based testing of dogs in Canada may provide important insight into the epidemiology of this canine and zoonotic infectious disease. Study objectives were to evaluate clinical canine Leptospira PCR test results from a large commercial laboratory to determine temporal and spatial distribution in Canada and identify dog, geographic and temporal risk factors for test-positive dogs. This cross-sectional study analyzed data obtained from IDEXX Laboratories, Inc. on 10,437 canine Leptospira PCR tests (blood and/or urine) submitted by Canada-based veterinarians (July 2009 to May 2018). Multivariable logistic regression was used to identify risk factors for test-positive dogs. Test-positive proportion varied widely annually (4.8-14.0%) and by location. Provinces with the highest test-positive proportion over the study period were Nova Scotia (18.5%) and Ontario (9.6%), with the prairie provinces (Manitoba and Alberta combined) having the lowest proportion (1.0%); the northern territories could not be evaluated due to limited testing. In the final model, dog age, sex, breed, month, and year test performed, and location (urban/rural, province) of the practice submitting the sample were significant predictors of a positive Leptospira PCR test. Dogs less than one year of age (OR = 2.1; 95% CI: 1.6-2.9), male sex (OR = 1.3; 1.1-1.5), toy breed (OR = 3.3; 2.5-4.4), and samples submitted from an urban practice (OR = 1.3; 1.0-1.8) had the greatest odds of a positive Leptospira PCR test as compared to referent groups. Significant two-way interactions between province-month and year-month highlight the complex spatial and temporal influences on leptospirosis occurrence in this region. Our work suggests a high incidence of canine leptospirosis regionally within Canada. Identifiable dog and location factors may assist in future targeted prevention efforts.

Feasibility of a tailored home-based exercise intervention during neoadjuvant chemotherapy in breast cancer patients.

PURPOSE: To evaluate the feasibility of a home-based moderate-to-vigorous intensity, phased (introduction, intermediate, maintenance), exercise prescription in breast cancer patients receiving cardiotoxic neoadjuvant chemotherapy. METHODS: Nineteen breast cancer patients were randomized to intervention or control for the duration of chemotherapy (16-24 weeks). The intervention was one aerobic exercise session at 80-90% VO2max for 25 min/week and 65%-75% VO2max for ≥ 50 min/week. Adherence to the tailored home-based program was assessed by heart rate monitors. Acceptability, tolerability, feasibility, efficacy, change in VO2max, and patient reported outcomes, safety, and clinical events were assessed. RESULTS: 25.7% of eligible women consented (acceptability). Adherence was 87.6%. Women were not able to maintain exercise intensity as chemotherapy progressed (23.7% of exercise minutes were completed at prescribed heart rate during maintenance). Efficacy of the intervention was demonstrated by maintenance of VO2max (-1.0 ± 13.2%) compared to (-27.5 ± 7.4%) the control group. Further, during and after therapy, patients in the intervention arm reported less fatigue (control-baseline: 14.4 ± 15.9; midpoint: 19.0 ± 11.4; follow-up: 29.4 ± 20.0; intervention-baseline: 29.2 ± 24.6; midpoint: 24.6 ± 14.4; follow-up: 23.6 ± 11.9), impairment in activities (control-baseline: 13.7 ± 16.0; midpoint: 32.8 ± 17.0; follow-up: 58.6 ± 27.9; intervention-baseline: 38.7 ± 31.8; midpoint: 47.1 ± 27.5; follow-up: 47.5 ± 31.0), and pain (control-baseline: 80.8 ± 17.1; midpoint: 73.9 ± 20.7; follow-up: 50.7 ± 25.7; intervention-baseline: 68.7 ± 28.4; midpoint: 61.4 ± 22.5; follow-up: 65.3 ± 22.4). There were no differences in adverse events, treatment delays, or pathological complete response. CONCLUSIONS: Neoadjuvant breast cancer patients maintained approximately one hour/week of moderate-intensity exercise over the course of their treatment. Further, this volume of exercise was sufficient to maintain fitness capacity and quality of life compared to the control group. TRIAL REGISTRY: ClinicalTrials.gov Identifier: NCT03280836, prospectively registered 9/13/2017, https://clinicaltrials.gov/ct2/show/NCT03280836 .