SSRI/SNRI Therapy is Associated With a Higher Risk of Gastrointestinal Bleeding in LVAD Patients.

BACKGROUND: Gastrointestinal bleeding (GIB) is common in left ventricular assist device (LVAD) patients. Serotonin release from platelets promotes platelet aggregation, and selective serotonin reuptake inhibitor/serotonin-norepinephrine reuptake inhibitor (SSRI/SNRI) therapy inhibits the transporter responsible for re-uptake. METHODS: We reviewed the records of LVAD (HeartMateII™, Abbott Medical, Lake Bluff, IL, USA and Heartware™, Medtronic, Minneapolis, MN, USA) patients at the Medical University of South Carolina and Johns Hopkins Hospital between January 2009 and January 2016. After exclusions, 248 patients were included for analysis. After univariate analysis, logistic regression multivariate analysis was performed to adjust for any demographic, cardiovascular, and laboratory data variables found to be associated with GI bleeding post-LVAD. RESULTS: Gastrointestinal bleeding occurred in 85 patients (35%) with 55% of GIBs due to arteriovenous malformations (AVMs). Of the total cohort, 105 patients received an SSRI or SNRI during LVAD support. Forty-four (44) SSRI/SNRI (41.9%) and 41 non-SSRI/SNRI (28.7%) patients had a GIB (RR 1.46, p = 0.03). Twenty-six (26) (24.8%) of the SSRI/SNRI patients had a GIB due to AVMs versus 21 (14.7%) of the non-SSRI/SNRI patients (RR 1.69, p = 0.05). In fully-adjusted multivariate regression analysis, SSRI/SNRI therapy was independently associated with GIB (OR 1.78, p = 0.045). For GIB, the number needed to harm (NNH) was 7.6. CONCLUSION: In conclusion, SSRI/SNRI therapy is independently associated with an increased risk of GIB in LVAD patients.

A Multidisciplinary Toxicity Team for Cancer Immunotherapy-Related Adverse Events.

BACKGROUND: Immune checkpoint inhibitors (ICIs) may cause immune-related adverse events (irAEs). Methods to obtain real-time multidisciplinary input for irAEs that require subspecialist care are unknown. This study aimed to determine whether a virtual multidisciplinary immune-related toxicity (IR-tox) team of oncology and medicine subspecialists would be feasible to implement, be used by oncology providers, and identify patients for whom multidisciplinary input is sought. PATIENTS AND METHODS: Patients treated with ICIs and referred to the IR-tox team in August 2017 through March 2018 were identified. Feasibility was defined as receipt of electronic referrals and provision of recommendations within 24 hours of referral. Use was defined as the proportion of referring providers who used the team's recommendations, which was determined through a postpilot survey. Demographics and tumor, treatment, and referral data were collected. Patient features and irAE associations were analyzed. RESULTS: The IR-tox team was found to be feasible and used: 117 referrals from 102 patients were received in 8 months, all providers received recommendations within 24 hours, 100% of surveyed providers used the recommendations, and 74% changed patient management based on IR-tox team recommendations. Referrals were for suspected irAEs (n=106; 91%) and suitability to treat with ICIs (n=11; 10%). In referred patients, median age was 64 years, 54% were men, 13% had prior autoimmunity, and 46% received ICI combinations versus monotherapy (54%). The most commonly referred toxicities were pneumonitis (23%), arthritis (16%), and dermatitis (15%); 15% of patients had multisystem toxicities. Multiple referrals were more common in those treated with combination ICIs (odds ratio [OR], 6.0; P=.035) or with multisystem toxicities (OR, 8.1; P=.005). The IR-tox team provided a new multidisciplinary forum to assist providers in diagnosing and managing complex irAEs. This model identifies educational and service needs, and patients with irAEs for whom multidisciplinary care is most sought. CONCLUSIONS: A virtual multidisciplinary toxicity team for irAEs was a feasible and used service, and facilitated toxicity identification and management.

Comprehensive metabolic modeling of multiple 13C-isotopomer data sets to study metabolism in perfused working hearts.

In many forms of cardiomyopathy, alterations in energy substrate metabolism play a key role in disease pathogenesis. Stable isotope tracing in rodent heart perfusion systems can be used to determine cardiac metabolic fluxes, namely those relative fluxes that contribute to pyruvate, the acetyl-CoA pool, and pyruvate anaplerosis, which are critical to cardiac homeostasis. Methods have previously been developed to interrogate these relative fluxes using isotopomer enrichments of measured metabolites and algebraic equations to determine a predefined metabolic flux model. However, this approach is exquisitely sensitive to measurement error, thus precluding accurate relative flux parameter determination. In this study, we applied a novel mathematical approach to determine relative cardiac metabolic fluxes using 13C-metabolic flux analysis (13C-MFA) aided by multiple tracer experiments and integrated data analysis. Using 13C-MFA, we validated a metabolic network model to explain myocardial energy substrate metabolism. Four different 13C-labeled substrates were queried (i.e., glucose, lactate, pyruvate, and oleate) based on a previously published study. We integrated the analysis of the complete set of isotopomer data gathered from these mouse heart perfusion experiments into a single comprehensive network model that delineates substrate contributions to both pyruvate and acetyl-CoA pools at a greater resolution than that offered by traditional methods using algebraic equations. To our knowledge, this is the first rigorous application of 13C-MFA to interrogate data from multiple tracer experiments in the perfused heart. We anticipate that this approach can be used widely to study energy substrate metabolism in this and other similar biological systems.

Endothelial expression of hypoxia-inducible factor 1 protects the murine heart and aorta from pressure overload by suppression of TGF-ß signaling.

Chronic systemic hypertension causes cardiac pressure overload leading to increased myocardial O(2) consumption. Hypoxia-inducible factor 1 (HIF-1) is a master regulator of O(2) homeostasis. Mouse embryos lacking expression of the O(2)-regulated HIF-1α subunit die at midgestation with severe cardiac malformations and vascular regression. Here we report that Hif1a(f/f);Tie2-Cre conditional knockout mice, which lack HIF-1α expression only in Tie2(+) lineage cells, develop normally, but when subjected to pressure overload induced by transaortic constriction (TAC), they manifest rapid cardiac decompensation, which is accompanied by excess cardiac fibrosis and myocardial hypertrophy, decreased myocardial capillary density, increased myocardial hypoxia and apoptosis, and increased TGF-ß signaling through both canonical and noncanonical pathways that activate SMAD2/3 and ERK1/2, respectively, within endothelial cells of cardiac blood vessels. TAC also induces dilatation of the proximal aorta through enhanced TGF-ß signaling in Hif1a(f/f);Tie2-Cre mice. Inhibition of TGF-ß signaling by treatment with neutralizing antibody or pharmacologic inhibition of MEK-ERK signaling prevented TAC-induced contractile dysfunction and pathological remodeling. Thus, HIF-1 plays a critical protective role in the adaptation of the heart and aorta to pressure overload by negatively regulating TGF-ß signaling in endothelial cells. Treatment of wild-type mice with digoxin, which inhibits HIF-1α synthesis, resulted in rapid cardiac failure after TAC. Although digoxin has been used for decades as an inotropic agent to treat heart failure, it does not improve survival, suggesting that the countertherapeutic effects of digoxin observed in the TAC mouse model may have clinical relevance.

Anomalous Origin of the Right Coronary Artery Causing Myocardial Ischemia: A Case for a Multimodality Imaging Approach.

A 46-year-old man was admitted with non-ST elevation myocardial infarction and newly diagnosed acutely decompensated heart failure. Echocardiogram demonstrated left ventricular ejection fraction of 30% with basal inferior and inferolateral akinesis. Coronary angiography showed mild diffuse coronary artery disease and an anomalous right coronary artery arising from the left coronary cusp. Further imaging was consistent with ischemia in the right coronary distribution. Etiology of ischemia was thought to be the anomalous right coronary artery, and surgical unroofing of the right coronary ostium was performed. Here, we report a multimodality imaging approach, including cardiac magnetic resonance, cardiac computed tomographic angiography, and single-photon emission computed tomography, to support the diagnosis and management of a patient with anomalous right coronary artery arising from the left coronary cusp.

Increased FOG-2 in failing myocardium disrupts thyroid hormone-dependent SERCA2 gene transcription.

Reduced expression of sarcoplasmic reticulum calcium ATPase (SERCA)2 and other genes in the adult cardiac gene program has raised consideration of an impaired responsiveness to thyroid hormone (T3) that develops in the advanced failing heart. Here, we show that human and murine cardiomyopathy hearts have increased expression of friend of GATA (FOG)-2, a cardiac nuclear hormone receptor corepressor protein. Cardiac-specific overexpression of FOG-2 in transgenic mice led to depressed cardiac function, activation of the fetal gene program, congestive heart failure, and early death. SERCA2 transcript and protein levels were reduced in FOG-2 transgenic hearts, and FOG-2 overexpression impaired T3-mediated SERCA2 expression in cultured cardiomyocytes. FOG-2 physically interacts with thyroid hormone receptor-alpha1 and abrogated even high levels of T3-mediated SERCA2 promoter activity. These results demonstrate that SERCA2 is an important target of FOG-2 and that increased FOG-2 expression may contribute to a decline in cardiac function in end-stage heart failure by impaired T3 signaling.

Use of genetics in the clinical evaluation and management of heart failure.

OPINION STATEMENT: Inherited forms of cardiomyopathy are common causes of heart failure. Applications of genetics in the evaluation and management of heart failure include the determination of inheritance patterns within families with cardiomyopathy, the evaluation of affected patients for syndromic features, the determination of people within families who are at risk of heart failure, and the identification of responsible gene mutations. Family planning may also be assisted by determination of a clear mutation that predisposes to heart failure. Genetic counseling is critical, and it should accompany the use of genetic testing in cardiovascular diseases. With the rapid pace of growth in technology that is used to determine DNA sequence, costs have declined and clinical application of genetic testing has expanded. This is particularly relevant for heart failure, because each of the familial forms of cardiomyopathy may be caused by a mutation in many different genes. Most families share a unique gene mutation, and appropriate interpretation of novel DNA variants is essential for proper use. The evaluation of risk of arrhythmia in familial forms of heart failure may benefit from genetic testing, as mutations in the genes encoding lamin A/C, desmin, and cardiac troponin T are associated with increased risk of sudden cardiac death. Because of its complexity and the rapid rate of change in available genetic testing options, the genetic evaluation of heart failure is best suited to tertiary referral centers with specific expertise in this area.

Calpain 9 as a therapeutic target in TGFß-induced mesenchymal transition and fibrosis.

Fibrosis is a common pathologic outcome of chronic disease resulting in the replacement of normal tissue parenchyma with a collagen-rich extracellular matrix produced by myofibroblasts. Although the progenitor cell types and cellular programs giving rise to myofibroblasts through mesenchymal transition can vary between tissues and diseases, their contribution to fibrosis initiation, maintenance, and progression is thought to be pervasive. Here, we showed that the ability of transforming growth factor-ß (TGFß) to efficiently induce myofibroblast differentiation of cultured epithelial cells, endothelial cells, or quiescent fibroblasts is dependent on the induced expression and activity of dimeric calpains, a family of non-lysosomal cysteine proteases that regulate a variety of cellular events through posttranslational modification of diverse substrates. siRNA-based gene silencing demonstrated that TGFß-induced mesenchymal transition of a murine breast epithelial cell line was dependent on induction of expression of calpain 9 (CAPN9), an isoform previously thought to be restricted to the gastrointestinal tract. Mice lacking functional CAPN9 owing to biallelic targeting of Capn9 were viable and fertile but showed overt protection from bleomycin-induced lung fibrosis, carbon tetrachloride-induced liver fibrosis, and angiotensin II-induced cardiac fibrosis and dysfunction. A predicted loss-of-function allele of CAPN9 is common in Southeast Asia, with the frequency of homozygosity matching the prediction of Hardy-Weinberg equilibrium. Together with the highly spatially restricted pattern of CAPN9 expression under physiologic circumstances and the heartiness of the murine knockout, these data provide a strong signature for tolerance of therapeutic strategies for fibrosis aimed at CAPN9 antagonism.

Four-Chamber Intracardiac Thrombi Complicating Wild-Type TTR Amyloidosis.

Cardiac amyloidosis is a rare disease, and its prevalence varies depending on the type of amyloid protein involved. Several case reports make reference to the increased risk of thrombosis and thromboembolic events in cardiac amyloidosis. We report a case of rapidly evolving, multichamber thrombi in a patient who was ultimately diagnosed with wild-type TTR cardiac amyloidosis.

Nonmyocyte ERK1/2 signaling contributes to load-induced cardiomyopathy in Marfan mice.

Among children with the most severe presentation of Marfan syndrome (MFS), an inherited disorder of connective tissue caused by a deficiency of extracellular fibrillin-1, heart failure is the leading cause of death. Here, we show that, while MFS mice (Fbn1C1039G/+ mice) typically have normal cardiac function, pressure overload (PO) induces an acute and severe dilated cardiomyopathy in association with fibrosis and myocyte enlargement. Failing MFS hearts show high expression of TGF-ß ligands, with increased TGF-ß signaling in both nonmyocytes and myocytes; pathologic ERK activation is restricted to the nonmyocyte compartment. Informatively, TGF-ß, angiotensin II type 1 receptor (AT1R), or ERK antagonism (with neutralizing antibody, losartan, or MEK inhibitor, respectively) prevents load-induced cardiac decompensation in MFS mice, despite persistent PO. In situ analyses revealed an unanticipated axis of activation in nonmyocytes, with AT1R-dependent ERK activation driving TGF-ß ligand expression that culminates in both autocrine and paracrine overdrive of TGF-ß signaling. The full compensation seen in wild-type mice exposed to mild PO correlates with enhanced deposition of extracellular fibrillin-1. Taken together, these data suggest that fibrillin-1 contributes to cardiac reserve in the face of hemodynamic stress, critically implicate nonmyocytes in disease pathogenesis, and validate ERK as a therapeutic target in MFS-related cardiac decompensation.

Angiotensin II antagonism is associated with reduced risk for gastrointestinal bleeding caused by arteriovenous malformations in patients with left ventricular assist devices.

BACKGROUND: Angiogenesis is implicated in formation of gastrointestinal arteriovenous malformations (AVMs). Angiotensin II signaling is involved in angiogenesis through the vascular endothelial growth factor (VEGF) and angiopoietin-2 pathways. We hypothesized that angiotensin-converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) therapy would be associated with a reduced risk of all-cause gastrointestinal bleeding (GIB) and AVM-associated GIB in patients with left ventricular assist devices (LVADs). METHODS: We reviewed records of all adult patients receiving a continuous-flow LVAD (HeartMate II or HeartWare HVAD) at Johns Hopkins Hospital between January 2004 and December 2014. Of 192 patients, 131 were included for final analyses. Logistic regression analysis adjusting for demographic, cardiovascular, and laboratory variables was used to assess the association of ACEI or ARB therapy with GIB. RESULTS: Of 131 patients, 100 received ACEI or ARB therapy during LVAD support. Of the 31 patients who did not receive ACEI or ARB, 15 experienced GIB (48%), with 9 caused by AVMs (29%). Of 100 patients who received ACEI or ARB therapy, 24 experienced GIB (24%), with 9 caused by AVMs (9%). Logistic regression hazards model demonstrated that ACEI or ARB therapy was independently associated with a reduced risk for all-cause GIB (odds ratio 0.29, 95% confidence interval 0.12-0.72) and AVM-related GIB (odds ratio 0.23, 95% confidence interval 0.07-0.71). CONCLUSIONS: Angiotensin II antagonism is associated with a reduced risk of AVM-related GIB in patients with LVADs. This association is independent of age, sex, blood pressure, renal function, international normalized ratio, LVAD type, and cardiomyopathy etiology.

Angiotensin II-dependent TGF-ß signaling contributes to Loeys-Dietz syndrome vascular pathogenesis.

Loeys-Dietz syndrome (LDS) is a connective tissue disorder that is characterized by a high risk for aneurysm and dissection throughout the arterial tree and phenotypically resembles Marfan syndrome. LDS is caused by heterozygous missense mutations in either TGF-ß receptor gene (TGFBR1 or TGFBR2), which are predicted to result in diminished TGF-ß signaling; however, aortic surgical samples from patients show evidence of paradoxically increased TGF-ß signaling. We generated 2 knockin mouse strains with LDS mutations in either Tgfbr1 or Tgfbr2 and a transgenic mouse overexpressing mutant Tgfbr2. Knockin and transgenic mice, but not haploinsufficient animals, recapitulated the LDS phenotype. While heterozygous mutant cells had diminished signaling in response to exogenous TGF-ß in vitro, they maintained normal levels of Smad2 phosphorylation under steady-state culture conditions, suggesting a chronic compensation. Analysis of TGF-ß signaling in the aortic wall in vivo revealed progressive upregulation of Smad2 phosphorylation and TGF-ß target gene output, which paralleled worsening of aneurysm pathology and coincided with upregulation of TGF-ß1 ligand expression. Importantly, suppression of Smad2 phosphorylation and TGF-ß1 expression correlated with the therapeutic efficacy of the angiotensin II type 1 receptor antagonist losartan. Together, these data suggest that increased TGF-ß signaling contributes to postnatal aneurysm progression in LDS.

Multi-scale biomechanical remodeling in aging and genetic mutant murine mitral valve leaflets: insights into Marfan syndrome.

Mitral valve degeneration is a key component of the pathophysiology of Marfan syndrome. The biomechanical consequences of aging and genetic mutation in mitral valves are poorly understood because of limited tools to study this in mouse models. Our aim was to determine the global biomechanical and local cell-matrix deformation relationships in the aging and Marfan related Fbn1 mutated murine mitral valve. To conduct this investigation, a novel stretching apparatus and gripping method was implemented to directly quantify both global tissue biomechanics and local cellular deformation and matrix fiber realignment in murine mitral valves. Excised mitral valve leaflets from wild-type and Fbn1 mutant mice from 2 weeks to 10 months in age were tested in circumferential orientation under continuous laser optical imaging. Mouse mitral valves stiffen with age, correlating with increases in collagen fraction and matrix fiber alignment. Fbn1 mutation resulted in significantly more compliant valves (modulus 1.34 ± 0.12 vs. 2.51 ± 0.31 MPa, respectively, P<.01) at 4 months, corresponding with an increase in proportion of GAGs and decrease in elastin fraction. Local cellular deformation and fiber alignment change linearly with global tissue stretch, and these slopes become more extreme with aging. In comparison, Fbn1 mutated valves have decoupled cellular deformation and fiber alignment with tissue stretch. Taken together, quantitative understanding of multi-scale murine planar tissue biomechanics is essential for establishing consequences of aging and genetic mutations. Decoupling of local cell-matrix deformation kinematics with global tissue stretch may be an important mechanism of normal and pathological biomechanical remodeling in valves.

Mitral valve disease in Marfan syndrome and related disorders.

Marfan syndrome (MFS) is a systemic disorder of the connective tissue with pleiotropic manifestations due to heterozygous FBN1 mutations and consequent upregulation of TGFß signaling in affected tissues. Myxomatous thickening and elongation of the mitral valve (MV) leaflets commonly occur in this condition. Investigation of murine models of this disease has led to improved understanding of the mechanisms that underlie many of the phenotypic features of MFS, including MV disease. Loeys-Dietz syndrome (LDS) is a related disorder due to heterozygous mutations in the genes encoding subunits of the TGFß receptor, and it may also involve the MV leaflets with similar elongation and thickening of the MV leaflets. Although the genetic basis and pathogenesis of nonsyndromic MV prolapse has been elusive to date, insights derived from monogenic disorders like MFS and LDS can be informative with regard to novel gene discovery and investigation into the pathogenesis of MV disease. This manuscript will review the prevalence of MV disease in MFS, its pathogenic basis as determined in mice with Fbn1 mutations, and ongoing studies that seek to better understand MV disease in the context of fibrillin-1 deficiency or excessive TGFß signaling.

A practical "ABCDE" approach to the metabolic syndrome.

The metabolic syndrome comprises a cluster of risk factors for cardiovascular disease and type 2 diabetes mellitus that are due to abdominal obesity and insulin resistance. This increasingly important proinflammatory condition remains both underrecognized and undertreated. To aid physicians in their approach to the metabolic syndrome, we assessed and synthesized the literature on cardiovascular risk assessment and early intervention for risk reduction. We performed a comprehensive search of MEDLINE and the Cochrane database for peer-reviewed clinical studies published from January 1, 1988, to December 31, 2007, augmented by consultation with content experts. We used the search terms metabolic syndrome, abdominal obesity, waist circumference, insulin resistance, cardiovascular disease, prediabetes, diabetes, treatment, prevention, aspirin, hypertension, cholesterol, atherogenic dyslipidemia, lifestyle therapy, diet, and exercise. Criteria used for study review were controlled study design, English language, relevance to clinicians, and validity based on experimental design and appropriateness of conclusions. Although growing evidence supports early intervention in patients with the metabolic syndrome, many physicians do not recognize the risk associated with this condition and fail to initiate early treatment. A comprehensive management plan can be assembled through an "ABCDE" approach: "A" for assessment of cardiovascular risk and aspirin therapy, "B" for blood pressure control, "C" for cholesterol management, "D" for diabetes prevention and diet therapy, and "E" for exercise therapy. This ABCDE approach provides a practical and systematic framework for encouraging metabolic syndrome recognition and for implementing a comprehensive, evidence-based management plan for the reduction of cardiovascular risk.

Beyond low-density lipoprotein cholesterol: defining the role of low-density lipoprotein heterogeneity in coronary artery disease.

Recent clinical trials in patients with coronary artery disease (CAD) provide evidence that low-density lipoprotein cholesterol (LDL-C) levels should be lowered even further to prevent recurrent CAD. However, despite more aggressive interventions for lowering LDL-C levels, the majority of CAD events go undeterred, perhaps related to the fact that intervention was not started earlier in life or that LDL-C levels represent an incomplete picture of atherogenic potential. Nevertheless, LDL-C remains the contemporary standard as the primary goal for aggressive LDL reduction. If triglycerides are >200 mg/dl, the measurement of non-high-density lipoprotein cholesterol (HDL-C) is recommended. Measurement of apolipoprotein (apo)B has been shown in nearly all studies to outperform LDL-C and non-HDL-C as a predictor of CAD events and as an index of residual CAD risk. This is because apoB reflects the total number of atherogenic apoB-containing lipoproteins and is a superior predictor of the number of low-density lipoprotein particles (LDL-P). Estimates of LDL-P and size can also be made by nuclear magnetic resonance spectroscopy, density gradient ultracentrifugation, and gradient gel electrophoresis. Although a number of studies show that such estimates predict CAD, LDL-P, and size often accompany low HDL-C and high triglyceride levels, and therefore such additional lipoprotein testing has not been recommended for routine screening and follow-up. Because apoB is a superior predictor of LDL-P, we recommend that apoB and the apoB/apoA-I ratio be determined after measurement of LDL-C, non-HDL-C, and the ratio of total cholesterol/HDL-C to better predict CAD and assess efficacy of treatment.