Análise de Custo-Efetividade da Terapia com Evolocumabe em Pacientes com Alto Risco de Eventos Cardiovasculares no Contexto do SUS - Brasil / Cost-Effectiveness Analysis of Evolocumab Therapy in Patients at High Risk of Cardiovascular Events in the Context of the Brazilian Unified Health System

Resumo Fundamento: Em associação às estatinas, os inibidores da pró-proteína convertase subtilisina/kexina tipo 9 (PCSK9) demonstraram ser eficazes na redução de eventos cardiovasculares em pacientes de alto risco. Objetivo: Analisar a custo-efetividade da implementação de evolocumabe para pacientes com alto risco de eventos cardiovasculares no contexto do Sistema Único de Saúde (SUS) no Brasil. Métodos: Um modelo de Markov foi utilizado, baseando-se em uma amostra ambulatorial de pacientes com doença arterial coronariana. Os desfechos primários analisados foram infarto agudo do miocárdio, acidente vascular cerebral isquêmico (AVCi), revascularização do miocárdio e morte cardiovascular. O resultado foi expresso por meio da razão de custo-efetividade incremental (RCEI), considerando-se uma taxa de desconto de 5% ao ano, e uma análise de sensibilidade foi realizada, tendo em vista a imprecisão de valores. Resultados: Selecionaram-se 61 pacientes com risco cardiovascular estimado em 35% em 10 anos, se em uso de atorvastatina 80mg/dia, e em 22,75%, se adicionado o evolocumabe. O custo global por paciente no período de 10 anos foi de R$ 46.522,44 no grupo em monoterapia com atorvastatina versus R$ 236.141,85 na terapia combinada, com uma efetividade global de 0,54 e 0,73, respectivamente. Isso resultou em uma RCEI R$ 1.011.188,07 (R$ 864.498,95 a R$ 1.296.748,43) por desfecho cardiovascular evitado. Conclusões: Apesar de não existirem padrões nacionais para custo-efetividade, os dados encontrados sugerem que a estratégia de associação do evolocumabe à terapia com estatina não é, no momento, custo-efetiva.

Abstract Background: Hypertrophic cardiomyopathy (HCM) and left ventricular hypertrophy (LVH) secondary to systemic hypertension (HTN) may be associated with left atrial (LA) functional abnormalities. Objectives: We aimed to characterize LA mechanics in HCM and HTN and determine any correlation with the extent of left ventricular (LV) fibrosis measured by cardiac magnetic resonance (CMR) in HCM patients. Methods: Two-dimensional speckle tracking-derived longitudinal LA function was acquired from apical views in 60 HCM patients, 60 HTN patients, and 34 age-matched controls. HCM patients also underwent CMR, with measurement of late gadolinium enhancement (LGE) extension. Association with LA strain parameters was analyzed. Statistical significance was set at p<0.05. Results: Mean LV ejection fraction was not different between the groups. The E/e' ratio was impaired in the HCM group and preserved in the control group. LA mechanics was significantly reduced in HCM, compared to the HTN group. LA strain rate in reservoir (LASRr) and in contractile (LASRct) phases were the best discriminators of HCM, with an area under the curve (AUC) of 0.8, followed by LA strain in reservoir phase (LASr) (AUC 0.76). LASRr and LASR-ct had high specificity (89% and 91%, respectively) and LASr had sensitivity of 80%. A decrease in 2.79% of LA strain rate in conduit phase (LASRcd) predicted an increase of 1cm in LGE extension (r2=0.42, β 2.79, p=0.027). Conclusions: LASRr and LASRct were the best discriminators for LVH secondary to HCM. LASRcd predicted the degree of LV fibrosis assessed by CMR. These findings suggest that LA mechanics is a potential predictor of disease severity in HCM.

The muscle-relaxing C-terminal peptide from troponin I populates a nascent helix, facilitating binding to tropomyosin with a potent therapeutic effect.

The conserved C-terminal end segment of troponin I (TnI) plays a critical role in regulating muscle relaxation. This function is retained in the isolated C-terminal 27 amino acid peptide (residues 184-210) of human cardiac TnI (HcTnI-C27): When added to skinned muscle fibers, HcTnI-C27 reduces the Ca2+-sensitivity of activated myofibrils and facilitates relaxation without decreasing the maximum force production. However, the underlying mechanism of HcTnI-C27 function is unknown. We studied the conformational preferences of HcTnI-C27 and a myopathic mutant, Arg192His, (HcTnI-C27-H). Both peptides were mainly disordered in aqueous solution with a nascent helix involving residues from Trp191 to Ile195, as shown by NMR analysis and molecular dynamics simulations. The population of nascent helix was smaller in HcTnI-C27-H than in HcTnI-C27, as shown by circular dichroism (CD) titrations. Fluorescence and isothermal titration calorimetry (ITC) showed that both peptides bound tropomyosin (αTm), with a detectably higher affinity (∼10 µM) of HcTnI-C27 than that of HcTnI-C27-H (∼15 µM), consistent with an impaired Ca2+-desensitization effect of the mutant peptide on skinned muscle strips. Upon binding to αTm, HcTnI-C27 acquired a weakly stable helix-like conformation involving residues near Trp191, as shown by transferred nuclear Overhauser effect spectroscopy and hydrogen/deuterium exchange experiments. With the potent Ca2+-desensitization effect of HcTnI-C27 on skinned cardiac muscle from a mouse model of hypertrophic cardiomyopathy, the data support that the C-terminal end domain of TnI can function as an isolated peptide with the intrinsic capacity of binding tropomyosin, providing a promising therapeutic approach to selectively improve diastolic function of the heart.

Loss of Cardiac Ferritin H Facilitates Cardiomyopathy via Slc7a11-Mediated Ferroptosis.

RATIONALE: Maintaining iron homeostasis is essential for proper cardiac function. Both iron deficiency and iron overload are associated with cardiomyopathy and heart failure via complex mechanisms. Although ferritin plays a central role in iron metabolism by storing excess cellular iron, the molecular function of ferritin in cardiomyocytes remains unknown. OBJECTIVE: To characterize the functional role of Fth (ferritin H) in mediating cardiac iron homeostasis and heart disease. METHODS AND RESULTS: Mice expressing a conditional Fth knockout allele were crossed with 2 distinct Cre recombinase-expressing mouse lines, resulting in offspring that lack Fth expression specifically in myocytes (MCK-Cre) or cardiomyocytes (Myh6-Cre). Mice lacking Fth in cardiomyocytes had decreased cardiac iron levels and increased oxidative stress, resulting in mild cardiac injury upon aging. However, feeding these mice a high-iron diet caused severe cardiac injury and hypertrophic cardiomyopathy, with molecular features typical of ferroptosis, including reduced glutathione (GSH) levels and increased lipid peroxidation. Ferrostatin-1, a specific inhibitor of ferroptosis, rescued this phenotype, supporting the notion that ferroptosis plays a pathophysiological role in the heart. Finally, we found that Fth-deficient cardiomyocytes have reduced expression of the ferroptosis regulator Slc7a11, and overexpressing Slc7a11 selectively in cardiomyocytes increased GSH levels and prevented cardiac ferroptosis. CONCLUSIONS: Our findings provide compelling evidence that ferritin plays a major role in protecting against cardiac ferroptosis and subsequent heart failure, thereby providing a possible new therapeutic target for patients at risk of developing cardiomyopathy.

Inhibition of the Hypoxia-Inducible Factor 1α-Induced Cardiospecific HERNA1 Enhance-Templated RNA Protects From Heart Disease.

BACKGROUND: Enhancers are genomic regulatory elements conferring spatiotemporal and signal-dependent control of gene expression. Recent evidence suggests that enhancers can generate noncoding enhancer RNAs, but their (patho)biological functions remain largely elusive. METHODS: We performed chromatin immunoprecipitation-coupled sequencing of histone marks combined with RNA sequencing of left ventricular biopsies from experimental and genetic mouse models of human cardiac hypertrophy to identify transcripts revealing enhancer localization, conservation with the human genome, and hypoxia-inducible factor 1α dependence. The most promising candidate, hypoxia-inducible enhancer RNA ( HERNA)1, was further examined by investigating its capacity to modulate neighboring coding gene expression by binding to their gene promoters by using chromatin isolation by RNA purification and λN-BoxB tethering-based reporter assays. The role of HERNA1 and its neighboring genes for pathological stress-induced growth and contractile dysfunction, and the therapeutic potential of HERNA1 inhibition was studied in gapmer-mediated loss-of-function studies in vitro using human induced pluripotent stem cell-derived cardiomyocytes and various in vivo models of human pathological cardiac hypertrophy. RESULTS: HERNA1 is robustly induced on pathological stress. Production of HERNA1 is initiated by direct hypoxia-inducible factor 1α binding to a hypoxia-response element in the histoneH3-lysine27acetylation marks-enriched promoter of the enhancer and confers hypoxia responsiveness to nearby genes including synaptotagmin XVII, a member of the family of membrane-trafficking and Ca2+-sensing proteins and SMG1, encoding a phosphatidylinositol 3-kinase-related kinase. Consequently, a substrate of SMG1, ATP-dependent RNA helicase upframeshift 1, is hyperphoshorylated in a HERNA1- and SMG1-dependent manner. In vitro and in vivo inactivation of SMG1 and SYT17 revealed overlapping and distinct roles in modulating cardiac hypertrophy. Finally, in vivo administration of antisense oligonucleotides targeting HERNA1 protected mice from stress-induced pathological hypertrophy. The inhibition of HERNA1 postdisease development reversed left ventricular growth and dysfunction, resulting in increased overall survival. CONCLUSIONS: HERNA1 is a novel heart-specific noncoding RNA with key regulatory functions in modulating the growth, metabolic, and contractile gene program in disease, and reveals a molecular target amenable to therapeutic exploitation.

Phosphomimetic-mediated in vitro rescue of hypertrophic cardiomyopathy linked to R58Q mutation in myosin regulatory light chain.

Myosin regulatory light chain (RLC) phosphorylation is important for cardiac muscle mechanics/function as well as for the Ca2+ -troponin/tropomyosin regulation of muscle contraction. This study focuses on the arginine to glutamine (R58Q) substitution in the human ventricular RLC (MYL2 gene), linked to malignant hypertrophic cardiomyopathy in humans and causing severe functional abnormalities in transgenic (Tg) R58Q mice, including inhibition of cardiac RLC phosphorylation. Using a phosphomimic recombinant RLC variant where Ser-15 at the phosphorylation site was substituted with aspartic acid (S15D) and placed in the background of R58Q, we aimed to assess whether we could rescue/mitigate R58Q-induced structural/functional abnormalities in vitro. We show rescue of several R58Q-exerted adverse phenotypes in S15D-R58Q-reconstituted porcine cardiac muscle preparations. A low level of maximal isometric force observed for R58Q- versus WT-reconstituted fibers was restored by S15D-R58Q. Significant beneficial effects were also observed on the Vmax of actin-activated myosin ATPase activity in S15D-R58Q versus R58Q-reconstituted myosin, along with its binding to fluorescently labeled actin. We also report that R58Q promotes the OFF state of myosin, both in reconstituted porcine fibers and in Tg mouse papillary muscles, thereby stabilizing the super-relaxed state (SRX) of myosin, characterized by a very low ATP turnover rate. Experiments in S15D-R58Q-reconstituted porcine fibers showed a mild destabilization of the SRX state, suggesting an S15D-mediated shift in disordered-relaxed (DRX)↔SRX equilibrium toward the DRX state of myosin. Our study shows that S15D-phosphomimic can be used as a potential rescue strategy to abrogate/alleviate the RLC mutation-induced phenotypes and is a likely candidate for therapeutic intervention in HCM patients.

Prevention of Sudden Cardiac Death in Hypertrophic Cardiomyopathy: What has Changed in The Guidelines? / Prevenção de Morte Súbita Cardíaca em Doentes com Miocardiopatia Hipertrófica: O Que Mudou nas Guidelines?

Abstract Background: The new European Society of Cardiology guidelines for hypertrophic cardiomyopathy (HCM) define the estimation of sudden cardiac death (SCD) risk as an integral part of clinical management. An implantable cardioverter defibrillator (ICD) is recommended (class IIa) when the risk is ≥ 6%. Objectives: To compare the SCD risk stratification according to the 2011 and 2014 recommendations for ICD implantation in patients with HCM. Methods: Retrospective study including 105 patients diagnosed with HCM. The indication for ICD was assessed using the 2011 and 2014 guidelines. Statistical analysis was performed using SPSS software version 19.0.0.2®. The tests performed were bilateral, considering the significance level of 5% (p < 0.05). Results: Regarding primary prevention, according to the 2011 ACCF/AHA recommendations, 39.0% of the patients had indication for ICD implantation (level of evidence IIa). Using the 2014 guidelines, only 12.4% of the patients had an indication for ICD implantation. Comparing the two risk stratification models for patients with HCM, we detected a significant reduction in the number of indications for ICD implantation (p < 0.001). Of the 41 patients classified as IIa according to the 2011 recommendations, 68.3% received a different classification according to the 2014 guidelines. Conclusion: Significant differences were found when comparing the SCD risk stratification for ICD implantation in the two guidelines. The current SCD risk score seems to identify many low-risk patients who are not candidates for ICD implantation. The use of this new score results in a significant reduction in the number of ICD implanted.

Resumo Fundamento: As recomendações de miocardiopatia hipertrófica (MCH) da Sociedade Europeia de Cardiologia aconselham a estimativa do risco de morte súbita cardíaca (MSC) como parte da avaliação clínica e decisão de implantação de cardioversor desfibrilador implantável (CDI). Objetivo: Comparar a estratificação de risco de MSC de acordo com as recomendações de 2011 e 2014. Métodos: Estudo retrospectivo de 105 pacientes com diagnóstico de MCH. Avaliou-se a recomendação para implantação de CDI conforme as recomendações de 2011 e 2014. A análise estatística foi realizada usando o software SPSS versão 19.0.0.2®. Os testes realizados foram bilaterais, sendo considerado o nível de significância de 5% (p< 0,05). Resultados: Conforme as recomendações ACCF/AHA 2011, 39,0% dos pacientes tinham indicação para implantação de CDI (nível de evidência classe IIa). Conforme as recomendações de 2014, apenas 12,4% dos pacientes apresentam indicação classe IIa para implantação de CDI. Comparando os dois modelos de estratificação de risco de MSC em MCH, verificou-se uma redução significativa na proporção de pacientes com indicação para implantação de CDI (p < 0,001). Do total de 41 pacientes classificados como IIa segundo as recomendações de 2011, 68,3% deles recebeu uma classificação diferente em 2014. Conclusão: No estudo foram encontradas diferenças significativas quando comparados os métodos de estratificação de risco de MSC para implantação de CDI. O escore de risco atual parece identificar muitos pacientes de baixo risco, que não são candidatos à implantação de CDI. A utilização desse novo escore resulta numa redução significativa do número de CDI implantados.

[Athlete's heart and hypertrophic cardiomyopathy: contribution on clinical and morphologic differentiation]. / Sportlerherz oder hypertrophe Kardiomyopathie? So gelingt die Differenzierung.

Hypertrophic cardiomyopathy (HCM) is a complex genetic disorder usually diagnosed in a young adult population. The diagnosis is based on echocardiographic identification of left ventricular hypertrophy, associated with a non-dilated hyperdynamic chamber in the absence of another cardiac or systemic disorder. The differentiation between HCM and physiological left ventricular hypertrophy (athlete`s heart) is essential: HCM is the main cause of exercise-induced sudden cardiac death in the young and especially in young athletes with overlapping features in Athlete's Heart or HCM. Differentiation between physiological left ventricular hypertrophy and HCM is challenging. Echocardiography allows detailed assessment of left ventricular structure and function which is fundamental. Additional genetic studies for identification of the broad HCM phenotype can be necessary to differentiate between Athlete's Heart and HCM.

Angiotensin receptor neprilysin inhibitor LCZ696 attenuates cardiac remodeling and dysfunction after myocardial infarction by reducing cardiac fibrosis and hypertrophy.

BACKGROUND: Angiotensin receptor neprilysin inhibitors (ARNi), beyond blocking angiotensin II signaling, augment natriuretic peptides by inhibiting their breakdown by neprilysin. The myocardial effects of ARNi have been little studied until recently. We hypothesized that LCZ696 attenuates left ventricular (LV) remodeling after experimental myocardial infarction (MI), and that this may be contributed to by inhibition of hypertrophy and fibrosis in cardiac cells. METHODS AND RESULTS: One week after MI, adult male Sprague-Dawley rats were randomized to treatment for 4 weeks with LCZ696 (68 mg/kg body weight perorally; MI-ARNi, n=11) or vehicle (MI-vehicle, n=6). Five weeks after MI, MI-ARNi versus MI-vehicle demonstrated lower LV end-diastolic diameter (by echocardiography; 9.7±0.2 versus 10.5±0.3 mm), higher LV ejection fraction (60±2 versus 47±5%), diastolic wall strain (0.23±0.02 versus 0.13±0.02), and circular strain (-9.8±0.5 versus -7.3±0.5%; all P<0.05). LV pressure-volume loops confirmed improved LV function. Despite similar infarct size, MI-ARNi versus MI-vehicle had lower cardiac weights (P<0.01) and markedly reduced fibrosis in peri-infarct and remote myocardium. Angiotensin II-stimulated incorporation of 3[H]leucine in cardiac myocytes and 3[H]proline in cardiac fibroblast was used to evaluate hypertrophy and fibrosis, respectively. The neprilysin inhibitor component of LCZ696, LBQ657, inhibited hypertrophy but not fibrosis. The angiotensin receptor blocker component of LCZ696, valsartan inhibited both hypertrophy and fibrosis. Dual valsartan+LBQ augmented the inhibitory effects of valsartan and the highest doses completely abrogated angiotensin II-mediated effects. CONCLUSIONS: LCZ696 attenuated cardiac remodeling and dysfunction after MI. This may be contributed to by superior inhibition of LCZ696 on cardiac fibrosis and cardiac hypertrophy than either stand-alone neprilysin inhibitor or angiotensin receptor blocker.

Inhibition of mammalian target of rapamycin with rapamycin reverses hypertrophic cardiomyopathy in mice with cardiomyocyte-specific knockout of PTEN.

The role of phosphatase and tensin homolog deleted from chromosome 10 (PTEN) in the maintenance of cardiac homeostasis still remains controversial. This study was designed to evaluate the role of cardiomyocyte-specific PTEN in the maintenance of cardiac homeostasis and the underlying mechanisms involved with a focus on autophagy, an evolutionarily conserved pathway for protein degradation. Cardiomyocyte-specific PTEN((flox/flox))/α-myosin heavy chain Cre mice, henceforth referred to as CM-PTENKO, were generated by crossing the floxed PTEN mice with α-myosin heavy chain Cre mice driven by a Cre recombinase promoter. The adult PTEN(-/-) mice displayed the phenotype of established hypertrophic cardiomyopathy, including unfavorable geometric, functional, and histological changes. Furthermore, cardiomyocyte-specific PTEN knockout mice exhibited increased cardiac mammalian target of rapamycin although suppressed autophagy. Treatment with rapamycin (2 mg/kg per day, IP), an inhibitor of mammalian target of rapamycin, for 1 month effectively reversed the established hypertrophic cardiomyopathy in CM-PTENKO mice. With rapamycin treatment, autophagy activity was significantly restored in the heart of CM-PTENKO mice. Taken together, our results demonstrate an essential role for cardiomyocyte PTEN in maintaining cardiac homeostasis under physiological condition. Cardiomyocyte-specific deletion of PTEN results in the development of hypertrophic cardiomyopathy possibly through a mechanism associated with mammalian target of rapamycin hyperactivation and autophagy suppression.

[Gender effect on cardiomyopathy]. / "Effetto donna" nelle cardiomiopatie.

The role of a gender effect (that means differences in clinical manifestations, access to therapies and response to treatments according to gender) in cardiomyopathies remains a matter of debate. Although recent studies have evaluated the differences in the clinical features and prognosis between the two sexes, many issues remain to be elucidated. At present, the only sex-specific condition that affects females is peripartum cardiomyopathy. Recent evidence suggests a pathogenetic role of a prolactin derivative, and ongoing clinical trials are investigating the possibility of targeted therapies using prolactin secretion inhibitors, such as bromocriptine and carbegoline. Although women were considered so far only carriers of X-linked diseases (Anderson-Fabry disease, Danon disease, Hunter syndrome and dystrophinopathies), clinical experience showed a wide spectrum of clinical manifestations in females due to random X chromosome inactivation. Conversely, in mitochondrial diseases (with matrilineal inheritance), cardiomyopathies may occur in the context of clinical multisystemic involvement without significant gender-related differences. Autosomal inherited cardiomyopathies also show different phenotypes and prognostic impact according to gender. The hypothesis of a premenopausal protective role of female hormones towards myocardial involvement has been raised by recent data on transtiretin-related amyloidosis and hypertrophic cardiomyopathy. Preexisting cardiomyopathies may affect pregnancy, labor and delivery in women, since all these conditions are associated with important hemodynamic changes. Women with low-risk hypertrophic cardiomyopathy (asymptomatic and without left ventricular outflow tract gradient) usually can tolerate pregnancy. Conversely, women who are symptomatic before pregnancy or have severe hypertrophy with important outflow tract gradient are at higher risk and should be referred to a tertiary center to be evaluated on a case by case basis. Pregnancy in women with dilated cardiomyopathy and significant left ventricular systolic dysfunction represents a high-risk condition. In addition, information on the clinical course and potential complications in pregnant women with arrhythmogenic right ventricular cardiomyopathy or restrictive cardiomyopathy is limited to individual reports.

The PTPN11 loss-of-function mutation Q510E-Shp2 causes hypertrophic cardiomyopathy by dysregulating mTOR signaling.

The identification of mutations in PTPN11 (encoding the protein tyrosine phosphatase Shp2) in families with congenital heart disease has facilitated mechanistic studies of various cardiovascular defects. However, the roles of normal and mutant Shp2 in the developing heart are still poorly understood. Furthermore, it remains unclear how Shp2 loss-of-function (LOF) mutations cause LEOPARD Syndrome (also termed Noonan Syndrome with multiple lentigines), which is characterized by congenital heart defects such as pulmonary valve stenosis and hypertrophic cardiomyopathy (HCM). In normal hearts, Shp2 controls cardiomyocyte size by regulating signaling through protein kinase B (Akt) and mammalian target of rapamycin (mTOR). We hypothesized that Shp2 LOF mutations dysregulate this pathway, resulting in HCM. For our studies, we chose the Shp2 mutation Q510E, a dominant-negative LOF mutation associated with severe early onset HCM. Newborn mice with cardiomyocyte-specific overexpression of Q510E-Shp2 starting before birth displayed increased cardiomyocyte sizes, heart-to-body weight ratios, interventricular septum thickness, and cardiomyocyte disarray. In 3-mo-old hearts, interstitial fibrosis was detected. Echocardiographically, ventricular walls were thickened and contractile function was depressed. In ventricular tissue samples, signaling through Akt/mTOR was hyperactivated, indicating that the presence of Q510E-Shp2 led to upregulation of this pathway. Importantly, rapamycin treatment started shortly after birth rescued the Q510E-Shp2-induced phenotype in vivo. If rapamycin was started at 6 wk of age, HCM was also ameliorated. We also generated a second mouse model in which cardiomyocyte-specific Q510E-Shp2 overexpression started after birth. In contrast to the first model, these mice did not develop HCM. In summary, our studies establish a role for mTOR signaling in HCM caused by Q510E-Shp2. Q510E-Shp2 overexpression in the cardiomyocyte population alone was sufficient to induce the phenotype. Furthermore, the pathomechanism was triggered pre- but not postnatally. However, postnatal rapamycin treatment could still reverse already established HCM, which may have important therapeutic implications.

Activation of adenosine A1 receptor attenuates tumor necrosis factor-α induced hypertrophy of cardiomyocytes.

Tumor necrosis factor (TNF)-α has been implicated in the pathogenesis of cardiac hypertrophy, while the activation of adenosine receptors has been shown to exert antihypertrophic effect on the heart. However, it remains unknown whether adenosine can attenuate hypertrophy induced by TNF-α. This study was aimed to address this issue using transverse aortic constriction (TAC) mouse models and cultured neonatal rat cardiomyocytes. Plasma TNF-α was significantly increased in hypertrophied hearts (Sham vs TAC group: 46.8±2.5 vs 67.0±1.6pg/ml, P=0.021), while myocardial TNF-α level, expression of TNF receptor 1 and TNF-α-converting enzyme were positively correlated with heart weight to body weight ratio (r=0.930, 0.676 and 0.891, respectively, P<0.01-0.05). Myocardial adenosine levels were increased significantly at 4 weeks (Sham vs TAC group: 16.15±1.59 vs 86.54±13.49 nmol/mg protein, P<0.01) and decreased from 6 to 11 weeks after TAC. N6-cyclopentyladenosine, an adenosine A1 receptor agonist inhibited protein synthesis of cardiomyocytes induced by TNF-α in a dose-dependent manner. This antihypertrophic effect could not be mimicked by agonists of A2a, A2b and A3 adenosine receptors. These findings indicate that TNF-α signal system plays important role in the process of cardiac hypertrophy, and activation of adenosine receptor 1 inhibits hypertrophy of cardiomyocytes induced by TNF-α.

The role of E2F1 in the development of hypertrophic cardiomyopathy.

The overexpression of the transcription factor, E2F1, induces hypertrophy and apoptosis with cell cycle re-entry in cardiomyocytes in vitro and in vivo, suggesting that targeting E2F1 may have therapeutic potential. Accordingly, we tested the hypothesis that blocking the E2F1-mediated signal transduction pathway prevents cardiac hypertrophy by treating E2F1 knockout mice (E2F1-/-) with either isoproterenol (ISO) or Angiotensin II (ANG). Echocardi-ography was used to measure left ventricular mass index and myocardial performance index, a measure of combined systolic and diastolic left ventricular function. In control mice (E2F1+/+) both ISO and ANG treatments induced cardiac hypertrophy, and impaired ventricular function in ANG treated mice. In contrast to previously published work, E2F1-/- mice also demonstrated a similar pattern of cardiac hypertrophy and function after either treatment. Atrial natriuretic peptide, a molecular marker of hypertrophy and necropsy-determined body weight-normalized left ventricle mass were similarly increased in ISO and ANG treated E2F1+/+ and E2F-/- mice, supporting the echocardiographic data. These data indicate that E2F1 is not necessary for the development of cardiac hypertrophy although studies using an overexpression approach suggest a causal role of E2F1. The reason for this discrepancy is unclear, although it is possible that other E2F-family members (e.g., E2F2) may play a compensatory role. In conclusion, our data demonstrate that cardiac hypertrophy can be induced in an E2F1-independent fashion and suggest that in contrast to previous reports, targeting E2F1 may not be a good therapeutic approach.

Cyclosporine attenuates cardiomyocyte hypertrophy induced by RAF1 mutants in Noonan and LEOPARD syndromes.

RAS activation is implicated in physiologic and pathologic cardiac hypertrophy. Cross-talk between the Ras and calcineurin pathways, the latter also having been implicated in cardiac hypertrophy, has been suspected for pathologic hypertrophy. Our recent discovery that germ-line mutations in RAF1, which encodes a downstream RAS effector, cause Noonan and LEOPARD syndromes with a high prevalence of hypertrophic cardiomyopathy provided an opportunity to elaborate the role of RAF1 in cardiomyocyte biology. Here, we characterize the role of RAF1 signaling in cardiomyocyte hypertrophy with an aim of identifying potential therapeutic targets. We modeled hypertrophic cardiomyopathy by infecting neonatal and adult rat cardiomyocytes (NRCMs and ARCMs, respectively) with adenoviruses encoding wild-type RAF1 and three Noonan/LEOPARD syndrome-associated RAF1 mutants (S257L, D486N or L613V). These RAF1 proteins, except D486N, engendered cardiomyocyte hypertrophy. Surprisingly, these effects were independent and dependent of mitogen activated protein kinases in NRCMs and ARCMs, respectively. Inhibiting Mek1/2 in RAF1 overexpressing cells blocked hypertrophy in ARCMs but not in NRCMs. Further, we found that endogenous and heterologously expressed RAF1 complexed with calcineurin, and RAF1 mutants causing hypertrophy signaled via nuclear factor of activated T cells (Nfat) in both cell types. The involvement of calcineurin was also reflected by down regulation of Serca2a and dysregulation of calcium signaling in NRCMs. Furthermore, treatment with the calcineurin inhibitor cyclosporine blocked hypertrophy in NRCMs and ARCMs overexpressing RAF1. Thus, we have identified calcineurin as a novel interaction partner for RAF1 and established a mechanistic link and possible therapeutic target for pathological cardiomyocyte hypertrophy induced by mutant RAF1. This article is part of a Special Issue entitled 'Possible Editorial'.

Marcadores genéticos como biomarcadores: hipertrofia cardíaca como exemplo / Genetic markers as biomarkers: cardiac hypertrophy as an example

A hipertrofia do ventrículo esquerdo constitui um dos mais poderosos de risco independentes para morbidade e mortalidade cardiovascular em pacientes de alto risco e na população geral. No mesmo nível de pressão arterial, alguns indivíduos desenvolvem hipertrofia do ventrículo esquerdo enquanto outros não o fazem, indicando uma suscetibilidade genética a essa condição. A hipertrofia do ventrículo esquerdo pode ser primária em doenças como cardiomiopatia hipertrofica ou, ao menos em parte, como um mecanismo compensatório para ativação crônica neuro-humoral e carga hemodinâmica anormal, sendo considerada uma adaptação estrutural do coração. O aumento da espessura da parede reduz o estresse na parede e mantém o desempenho da parede na presença do aumento da carga mecânica. Estudos recentes sugerem a existência de marcadores de suscetibilidade à hipertrofia em diversos genes, como o da enzima conversora de angiotensina, do angiotensinogênio, dos receptores tipo 1 e 2 da angiotensina II, da aldosterona sintetase, do receptor ativado...

Left ventricular hypertrophy is one of the strongest independent risk factors for cardiovascular morbidity and mortality in high risk patients and the general population. At the same blood pressure level, some individuals develop left ventricular hypertrophy while others do not, indicating a genetic susceptibility to this condition. Left ventricular hypertrophy may be primary in diseases such as hypertrophic cardiomyopathy or it may be partially due to a compensatory mechanism for chronic neurohumoral activation and abnormal hemodynamic load, considered as a structural adaptation of heart. Increased wall thickness reduces wall stress and maintains cardiac performance in the presence of increased mechanical load. Recent studies suggest the existence of markers of susceptibility to hypertrophy in several genes such as angiotensin converting enzyme, angiotensinogen, angiotensin II type 1 and type 2 receptors, aldosterone synthetase, peroxisome proliferator-activated receptor and G-protein ß3 subunit. Since it involves multiple environmental, behavior and genetic factors, the study of left ventricular hypertrophy is a challenge. However, the knowledge of molecular and genetic bases of left ventricular hypertrophy may contribute to a more accurate understanding of the pathogenesis of this condition and offers a promising future for its treatment and prevention.

Cuándo practicar un análisis genético molecular en pacientes con miocardiopatía hipertrófica: [revisión] / Hypertrophic cardiomyopathy: who should be screened and when?: [review]

La miocardiopatía hipertrófica (MCH) es una enfermedad frecuentemente hereditaria, causada por mutaciones en varios genes implicados en el funcionamiento del sarcómero cardíaco. Aunque hay más de 12 genes en los que se han hallado mutaciones, la mayoría de los pacientes o sus familias tienen una mutación en el gen MYH7, MYBPC3, TNNT2, TNNI3, o TPM1. Dado que los parámetros clínico-patológicos tienen una capacidad limitada para predecir los efectos adversos, se ha investigado la posibilidad de emplear los hallazgos genéticos con este fin (por ejemplo, para predecir el riesgo de muerte súbita) y en la toma de decisiones terapéuticas. Actualmente, podemos concluir que para la mayoría de las mutaciones no se puede derivar un comportamiento clínico definido, algo que se podía suponer si consideramos que las manifestaciones de la MCH son heterogéneas, incluso entre los afectados de una misma familia. En este artículo revisamos los aspectos fundamentales de los análisis moleculares con fines diagnósticos en la MCH y las posibilidades de aplicar los hallazgos genéticos en la toma de decisiones.

Anestesia para gestante cardiopata / Anaesthesia for pregnant cardiac disease

Gestantes com doença cardíaca habitualmente possuem prognóstico favorável tanto materno quanto fetal. Com exceção das pacientes com a síndrome de Eisenmenger, hipertensão pulmonar primária e síndrome de Marfan com aortopatia, morte materna durante a gravidez em pacientes cardiopatas é rara. A gravidez por si só impõe modificações hemodinâmicas significativas, colocando à prova o sistema cardiovascular. Doença cardíaca reumática é a mais frequente nas gestantes, e o edema agudo pulmonar, a complicação mais comum. Defeito do septo atrial é a cardiopatia congênita acianótica mais prevalente na população adulta, enquanto que a Tetralogia de Fallot é a mais frequente das cardiopatias congênitas cianóticas. Gravidez e cardiopatia são uma associação de grandes desafios para o anestesiologista. Para evitar complicações decorrentes da morbidade ou mortalidade materno-fetal, o anestesiologista deve conhecer a evolução da doença durante a gravidez. Aqui são discutidas a fisiopatologia, apresentação clínica e a condução anestésica das doenças cardíacas valvulares adquiridas, das doenças cardíacas congênitas, da doença isquêmica do miocárdio e das miocardiopatias na gravidez.

Pregnancy in most women with heart disease has a favorable maternal and fetal outcome. With the exception of patients with Eisenmenger syndrome, pulmonary hypertension primary, and Marfan syndrome with aortopathy, maternal death during pregnancy in women with heart disease is rare. Pregnancy per se imposes significant hemodynamic changes placing a major burden on the cardiovascular system. Rheumatic heart disease remains the most frequent heart disease in the pregnant population and the pulmonary edema is the most frequent complication. Atrial septal defect is the most frequent congenital acianotic heart disease in the adult population, whereas tetralogy of Fallot is the most common cyanotic congenital heart disease. Pregnancy and heart disease present a unique challenge to the anesthesiologist. To avoid untoward complications resulting in significant maternal and/or fetal morbidity or mortality, the anesthesiologist must be familiar about the progression of heart disease during pregnancy. In this article, we review the pathophysiology, clinical presentation, and anesthetic management of valvular, congenital, vascular and ischemic heart disease, and cardiomyopathy in pregnancy.

Comparison of U.S. and Italian experiences with sudden cardiac deaths in young competitive athletes and implications for preparticipation screening strategies.

Controversy has evolved over the most practical and effective strategy for preparticipation cardiovascular screening of competitive athletes to detect unsuspected cardiovascular disease and prevent sudden death on the athletic field. Athlete screening in the Veneto region of Italy is part of a national program (with 12-lead electrocardiography) that has reported the detection of previously undiagnosed hypertrophic cardiomyopathy and a decrease in the cardiovascular death rate in young athletes. In this study, over time periods of similar length, cardiovascular-related mortality rates in Veneto athletes were compared with those of a demographically similar region of the United States (Minnesota) in which screening is limited to history and physical examination. There were 55 sudden cardiovascular deaths reported in Veneto over 26 years (2.1/year), compared with 22 deaths in 23 years (0.96/year) in Minnesota. Over the recent and comparable 11-year period, 1993 to 2004, 12 deaths were reported in Veneto and 11 in Minnesota. When analyzed as deaths per 100,000 person-years, Veneto exceeded Minnesota for all years combined (1.87 for 1979 to 2004 vs 1.06 for 1985 to 2007, respectively, p = 0.006), although the 2 regions did not differ significantly for 1993 to 2004 (0.87 vs 0.93, respectively, p = 0.88) or most recently for 2001 to 2004 (0.43 vs 0.90, respectively, p = 0.38). In conclusion, sudden cardiovascular deaths in young competitive athletes occurred at a low rate in both Veneto and Minnesota. Despite different preparticipation screening strategies, athlete sudden death rates in these demographically similar regions of the United States and Italy have not differed significantly in recent years. These data do not support a lower mortality rate associated with preparticipation screening programs involving routine electrocardiography and examinations by specially trained personnel.

Heart changes in 17-day-old fetuses of diabetic ICR (Institute of Cancer Research) mothers: improvement with maternal immune stimulation.

Maternal diabetes mellitus is associated with increased fetal teratogenesis, including cardiovascular defects. Non-specific maternal immune stimulation with Freund's complete adjuvant (FCA) or interferon gamma (IFNgamma) has been associated with protection against birth malformations. Using a diabetic mouse model, late-gestation fetal heart and great vessel morphology were analyzed. Four groups of mice were used: non-diabetic females as a control group, hyperglycemic females induced by streptozotocin as a diabetic group, and diabetic females injected either with FCA or IFNgamma. At day 17 of gestation, females were euthanized and one fetus was arbitrarily selected per litter for fixation and sectioning. Treatment-induced changes in cardiac development were assessed from digital images of serial sections taken at standardized levels in the thorax. One-way parametric and non-parametric ANOVA and ordinal logistic regression were performed to compare the difference among groups (P<0.05). Maternal hyperglycemia altered morphology of the late-gestation fetal mouse heart by causing ventricular chamber dilation, sectional myocardial reduction, and an increase in transversal aortic area. FCA protected the fetal heart from cavitary dilation in diabetic mothers. FCA and IFNgamma protected the fetal heart against reduction of myocardial area, and ascending thoracic aorta dilation. Consequences of late gestation heart chamber dilation and myocardial reduction are not yet known. Maternal immune stimulation partially protected against these developmental defects by mechanisms that remain unclear.