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1.
Respir Res ; 23(1): 284, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36243869

RESUMO

BACKGROUND AND OBJECTIVE: The definition of pre-capillary pulmonary hypertension (PH) has been modified, with lowering of the mean pulmonary arterial pressure (mPAP) threshold from 25 to 20 mmHg and addition of a mandatory criterion of pulmonary vascular resistance (PVR) ≥ 2 Wood units (WU). Our objectives were: 1/ to estimate the proportion of patients reclassified as having pre-capillary PH when using the new 2022 ESC/ERS hemodynamic criteria (i.e. mPAP 21-24 mmHg and PVR ≥ 2 WU), and to describe their clinical characteristics and outcome; and 2/ to study the relationship between PVR and survival in patients with mPAP > 20 mmHg. METHODS: We retrospectively analyzed consecutive SSc patients included in our National Reference Center for a first right-heart catheterization between 2003 and 2018. The association between survival and PVR was studied using smoothing splines. RESULTS: We included 126 SSc patients with mPAP > 20 mmHg. Among them, 16 (13%) had a baseline mPAP value between 21 and 24 mmHg and PVR ≥ 2 mmHg and were reclassified as pre-capillary PH; 10 of which (62%) raised their mPAP ≥ 25 mmHg during follow-up. In patients with mPAP > 20 mmHg, we observed a linear relation between PVR and mortality for values < 6 WU. CONCLUSION: A significant proportion of SSc patients is reclassified as having pre-capillary PH with the new 2022 ESC/ERS hemodynamic definition. Lowering the PVR threshold from 3 to 2 WU captures patients at risk of raising their mPAP > 25 mmHg, with a possibly less severe disease.


Assuntos
Hipertensão Pulmonar , Escleroderma Sistêmico , Hemodinâmica , Humanos , Hipertensão Pulmonar/diagnóstico , Estudos Retrospectivos , Escleroderma Sistêmico/diagnóstico , Resistência Vascular
2.
Eur Radiol ; 32(7): 4574-4586, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35286410

RESUMO

BACKGROUND: In the stratification of potential causes of PH, current guidelines recommend performing V/Q lung scintigraphy to screen for CTEPH. The recognition of CTEPH is based on the identification of lung segments or sub-segments without perfusion but preserved ventilation. The presence of mismatched perfusion defects has also been described in a small proportion of idiopathic pulmonary arterial hypertension (PAH) and pulmonary veno-occlusive disease and/or pulmonary capillary hemangiomatosis (PVOD/PCH). Dual-energy CT lung perfusion changes have not been specifically investigated in these two entities. PURPOSE: To compare dual-energy CT (DECT) perfusion characteristics in PAH and PVOD/PCH, with specific interest in PE-type perfusion defects. MATERIALS AND METHODS: Sixty-three patients with idiopathic or heritable PAH (group A; n = 51) and PVOD/PCH (group B; n = 12) were investigated with DECT angiography with reconstruction of morphologic and perfusion images. RESULTS: The number of patients with abnormal perfusion did not differ between group A (35/51; 68.6%) and group B (6/12; 50%) (p = 0.31) nor did the mean number of segments with abnormal perfusion per patient (group A: 17.9 ± 4.9; group B: 18.3 ± 4.1; p = 0.91). The most frequent finding was the presence of patchy defects in group A (15/35; 42.9%) and a variable association of perfusion abnormalities in group B (4/6; 66.7%). The median percentage of segments with PE-type defects per patient was significantly higher in group B than in group A (p = 0.041). Two types of PE-type defects were depicted in 8 patients (group A: 5/51; 9.8%; group B: 3/12; 25%), superimposed on PH-related lung abnormalities (7/8) or normal lung (1/8). The iodine concentration was significantly lower in patients with abnormal perfusion (p < 0.001) but did not differ between groups. CONCLUSION: Perfusion abnormalities did not differ between the two groups at the exception of a higher median percentage of segments with PE-type defects in patients with PVOD/PCH. KEY POINTS: • Patchy perfusion defect was the most frequent pattern in PAH. • A variable association of perfusion abnormalities was seen in PVOD/PCH. • Lobular and PE-type perfusion defects larger than a sub-segment were depicted in both PAH and PVOD/PCH patients.


Assuntos
Hemangioma Capilar , Hipertensão Pulmonar , Hipertensão Arterial Pulmonar , Pneumopatia Veno-Oclusiva , Hipertensão Pulmonar Primária Familiar/complicações , Hemangioma Capilar/complicações , Hemangioma Capilar/diagnóstico por imagem , Humanos , Pulmão , Perfusão , Pneumopatia Veno-Oclusiva/complicações , Pneumopatia Veno-Oclusiva/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos
3.
Arch Cardiovasc Dis ; 115(3): 169-178, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35283039

RESUMO

BACKGROUND: Previous studies have shown that pulmonary hypertension is a predictor of mortality in patients with systolic heart failure (SHF). Persistent pulmonary hypertension after a reactivity test is associated with a worse outcome after transplantation. Recent studies have shown the utility of different haemodynamic parameters. AIMS: To define best haemodynamic parameters for risk stratification in patients with advanced systolic heart failure. METHODS: We included 425 consecutive patients who underwent a right heart catheterization with an inotropic challenge if indicated. RESULTS: During a median (interquartile range) follow-up of 1.67 (0.49-4.49) years, there were 151 major cardiac events (126 cardiovascular deaths and 25 postoperative deaths after ventricular assist device implantation or heart transplantation). The most powerful independent predictors of major cardiac events were baseline right atrial pressure (RAP) (hazard ratio [HR]: 1.09, 95% confidence interval [CI]: 1.06-1.12; P<0.0001) and baseline pulmonary vascular resistance (PVR) (HR: 1.10; 95% CI: 1.03-1.17; P=0.002). After inotropic challenge, the only independent predictor was mean pulmonary arterial pressure (mPAP) (HR: 1.06; 95% CI: 1.03-1.09; P<0.0001). The combination of PVR (≤or>3 Wood units), RAP (30mmHg) was the best predictor of major events. CONCLUSION: We suggest using a simple algorithm based on baseline PVR, baseline RAP and mPAP after the inotropic challenge for the risk stratification of stable patients with advanced systolic heart failure.


Assuntos
Insuficiência Cardíaca Sistólica , Insuficiência Cardíaca , Hipertensão Pulmonar , Cateterismo Cardíaco/efeitos adversos , Insuficiência Cardíaca Sistólica/diagnóstico , Insuficiência Cardíaca Sistólica/terapia , Hemodinâmica , Humanos , Estudos Retrospectivos , Medição de Risco
4.
ESC Heart Fail ; 8(2): 1509-1521, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33619905

RESUMO

AIMS: Iron deficiency (ID) occurs in about 50% of patients with heart failure (HF). The European Society of Cardiology (ESC) recommends ID diagnostic testing in newly diagnosed patients with HF and during follow-up, with intravenous iron supplementation (IS) only recommended in patients with HF with reduced ejection fraction (HFrEF). This study aimed to assess prevalence, clinical characteristics, and application of ESC guidelines for ID and IS in patients with HF in the real-life clinical setting. METHODS AND RESULTS: The French transversal multicentre OFICSel registry (300 cardiologists) conducted in 2017 included patients hospitalized for HF at least once in the previous 5 years. Diverse adult patients were eligible including inpatients and outpatients and those with acute and chronic HF. Data were collected from cardiologists and patients using study-specific surveys. Data included demographic and clinical data, as well as HF and ID management data. Overall, 2822 patients, mainly male (69.3%) with a median age of 69 years (interquartile range 58-78), were included. A total of 1075 patients (38.1%) were tested for ID, with 364 (33.9%) diagnosed. Of these, 168 (46.2%) received IS: 128 (76.2%) intravenous IS and 40 (23.8%) oral. Among the 201 patients with HFrEF diagnosed with ID, 99 (49.3%) received IS: 79 (79.8%) intravenous IS and 20 (20.2%) oral. CONCLUSIONS: In clinical practice, only one-third of patients with HF had a diagnostic test for ID. In patients with ID with HFrEF, only 39.3% received intravenous IS as recommended. Thus, in general, cardiologists should be encouraged to follow the ESC guidelines to ensure optimal treatment for patients with HF.


Assuntos
Anemia Ferropriva , Insuficiência Cardíaca , Adulto , Idoso , Anemia Ferropriva/diagnóstico , Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/epidemiologia , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Humanos , Ferro , Masculino , Sistema de Registros , Volume Sistólico
6.
J Hepatol ; 73(1): 130-139, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32145258

RESUMO

BACKGROUND & AIMS: Long-term outcomes in portopulmonary hypertension (PoPH) are poorly studied in the current era of pulmonary hypertension management. We analysed the effect of pulmonary arterial hypertension (PAH)-targeted therapies, survival and predictors of death in a large contemporary cohort of patients with PoPH. METHODS: Data from patients with PoPH consecutively enrolled in the French Pulmonary Hypertension Registry between 2007 and 2017 were collected. The effect of initial treatment strategies on functional class, exercise capacity and cardiopulmonary haemodynamics were analysed. Survival and its association with PAH- and hepatic-related characteristics were also examined. RESULTS: Six hundred and thirty-seven patients (mean age 55 ± 10 years; 58% male) were included. Fifty-seven percent had mild cirrhosis, i.e. Child-Pugh stage A. The median model for end-stage liver disease (MELD) score was 11 (IQR 9-15). Most patients (n = 474; 74%) were initiated on monotherapy, either with a phosphodiesterase-5 inhibitor (n = 336) or with an endothelin-receptor antagonist (n = 128); 95 (15%) were initiated on double oral combination therapy and 5 (1%) on triple therapy. After a median treatment time of 4.5 months, there were significant improvements in functional class (p <0.001), 6-minute walk distance (6MWD) (p <0.0001) and pulmonary vascular resistance (p <0.0001). Overall survival rates were 84%, 69% and 51% at 1, 3 and 5 years, respectively. Baseline 6MWD, sex, age and MELD score or Child-Pugh stage were identified as independent prognostic factors. Survival from PoPH diagnosis was significantly better in the subgroup of patients who underwent liver transplantation (92%, 83% and 81% at 1, 3 and 5 years, respectively). CONCLUSION: Survival of patients with PoPH is strongly associated with the severity of liver disease. Patients who underwent liver transplantation had the best long-term outcomes. LAY SUMMARY: Portopulmonary hypertension is defined by the presence of pulmonary arterial hypertension in the context of chronic liver disease and is characterized by progressive shortness of breath and exercise limitation. The presence of severe pulmonary arterial hypertension in liver transplant candidates represents a contraindication for such a surgery; however, treatments targeting pulmonary arterial hypertension are efficacious, allowing for safe transplantation and conferring good survival outcomes in those who undergo liver transplantation.


Assuntos
Antagonistas dos Receptores de Endotelina/uso terapêutico , Hipertensão Portal , Cirrose Hepática , Inibidores da Fosfodiesterase 5/uso terapêutico , Hipertensão Arterial Pulmonar , Sistema Cardiovascular/fisiopatologia , Tolerância ao Exercício , Feminino , França/epidemiologia , Estado Funcional , Humanos , Hipertensão Portal/diagnóstico , Hipertensão Portal/mortalidade , Hipertensão Portal/fisiopatologia , Cirrose Hepática/diagnóstico , Cirrose Hepática/fisiopatologia , Cirrose Hepática/cirurgia , Transplante de Fígado/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Administração dos Cuidados ao Paciente/métodos , Prognóstico , Hipertensão Arterial Pulmonar/mortalidade , Hipertensão Arterial Pulmonar/fisiopatologia , Hipertensão Arterial Pulmonar/terapia , Índice de Gravidade de Doença , Análise de Sobrevida
7.
Arch Cardiovasc Dis ; 111(11): 686-701, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29861294

RESUMO

BACKGROUND: Coronary artery disease (CAD) is the leading cause of systolic heart failure (HF). Cardiac magnetic resonance imaging (CMR) is a non-invasive technique that detects a myocardial infarction scar as subendocardial or transmural late gadolinium enhancement (st-LGE). AIM: We sought to evaluate whether a lack of st-LGE could rule out CAD in new-onset systolic HF of unknown aetiology. METHODS: We included 232 consecutive patients with new-onset HF and left ventricular ejection fraction ≤35% who underwent both coronary angiography and CMR to assess HF aetiology. CAD was defined as the presence of coronary artery stenosis≥50% on a coronary angiogram. We assessed sensitivity, specificity, and positive and negative likelihood ratios (PLR and NLR) of the presence of st-LGE to detect underlying CAD. A complementary meta-analysis of 11 studies (including ours) was also performed. RESULTS: In our study, 49 (21.1%) patients had CAD. The sensitivity and specificity of the presence of st-LGE to detect CAD were 69 and 92%, respectively. PLR and NLR were 8.47 and 0.33, respectively. In the meta-analysis, 1227 patients were included, and the prevalence of CAD ranged from 19.2 to 68.3%. Sensitivity, specificity, PLR and NLR were 87% (95% confidence interval [CI] 0.80-0.92), 93% (95% CI 0.89-0.96), 12.91 (95% CI 7.70-21.64) and 0.14 (95% CI 0.09-0.22), respectively. Altogether, 55 patients presented CAD with no st-LGE; inversely, 75 patients presented st-LGE with no CAD. CONCLUSION: With a CMR specificity of 93%, the absence of st-LGE rules out significant underlying CAD in patients with systolic HF of unknown aetiology in most cases.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Insuficiência Cardíaca Sistólica/etiologia , Imageamento por Ressonância Magnética , Adulto , Idoso , Meios de Contraste/administração & dosagem , Angiografia Coronária , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/fisiopatologia , Estenose Coronária/complicações , Estenose Coronária/fisiopatologia , Feminino , Insuficiência Cardíaca Sistólica/diagnóstico , Insuficiência Cardíaca Sistólica/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Sistema de Registros , Reprodutibilidade dos Testes , Fatores de Risco , Índice de Gravidade de Doença , Volume Sistólico , Função Ventricular Esquerda
8.
Circ Heart Fail ; 11(6): e004838, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29891738

RESUMO

BACKGROUND: Left ventricular remodeling (LVR) after myocardial infarction is associated with an increased risk of heart failure and death. In spite of a modern therapeutic approach, LVR remains relatively frequent and difficult to predict in clinical practice. Our aim was to identify new biomarkers of LVR and understand their involvement in its development. METHODS AND RESULTS: Proteomic analysis of plasma from the REVE-2 study (Remodelage Ventriculaire)-a study dedicated to the analysis of LVR which included 246 patients after a first anterior myocardial infarction-identified increased plasma levels of CLU (clusterin) in patients with high LVR. We used a rat model of myocardial infarction to analyze CLU expression in the LV and found a significant increase that was correlated with LVR parameters. We found increased CLU expression and secretion in primary cultures of rat neonate cardiomyocytes hypertrophied by isoproterenol. Silencing of CLU in hypertrophied neonate cardiomyocytes induced a significant decrease in cell size, ANP (atrial natriuretic peptide), and BNP (B-type natriuretic peptide) expression, associated with a decreased ERK (extracellular signal-regulated kinase) 1/2 activity, suggesting a prohypertrophic role of CLU. We then confirmed a significant increase of both intracellular p-CLU (precursor form of CLU) and m-CLU (mature form of CLU) in failing human hearts. Finally, the circulating levels of CLU (secreted form) were increased in patients with chronic heart failure who died from cardiovascular cause during a 3-year follow-up (n=99) compared with survivors (n=99). CONCLUSIONS: Our results show for the first time that plasma CLU levels are associated with LVR post-myocardial infarction, have in part a cardiac origin, and are a predictor of early death in heart failure patients.


Assuntos
Clusterina/metabolismo , Insuficiência Cardíaca/sangue , Infarto do Miocárdio/sangue , Remodelação Ventricular , Adulto , Biomarcadores/sangue , Ecocardiografia/métodos , Feminino , Coração/fisiopatologia , Insuficiência Cardíaca/complicações , Humanos , Masculino , Infarto do Miocárdio/fisiopatologia , Proteômica
9.
Eur Radiol ; 28(12): 5100-5110, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29846802

RESUMO

OBJECTIVES: To evaluate the concordance between DECT perfusion and ventilation/perfusion (V/Q) scintigraphy in diagnosing chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: Eighty patients underwent V/Q scintigraphy and DECT perfusion on a 2nd- and 3rd-generation dual-source CT system. The imaging criteria for diagnosing CTEPH relied on at least one segmental triangular perfusion defect on DECT perfusion studies and V/Q mismatch on scintigraphy examinations. RESULTS: Based on multidisciplinary expert decisions that did not include DECT perfusion, 36 patients were diagnosed with CTEPH and 44 patients with other aetiologies of PH. On DECT perfusion studies, there were 35 true positives, 6 false positives and 1 false negative (sensitivity 0.97, specificity 0.86, PPV 0.85, NPV 0.97). On V/Q scans, there were 35 true positives and 1 false negative (sensitivity 0.97, specificity 1, PPV 1, NPV 0.98). There was excellent agreement between CT perfusion and scintigraphy in diagnosing CTEPH (kappa value 0.80). Combined information from DECT perfusion and CT angiographic images enabled correct reclassification of the 6 false positives and the unique false negative case of DECT perfusion. CONCLUSION: There is excellent agreement between DECT perfusion and V/Q scintigraphy in diagnosing CTEPH. The diagnostic accuracy of DECT perfusion is reinforced by the morpho-functional analysis of data sets. KEY POINTS: • Chronic thromboembolic pulmonary hypertension (CTEPH) is potentially curable by surgery. • The triage of patients with pulmonary hypertension currently relies on scintigraphy. • Dual-energy CT (DECT) can provide standard diagnostic information and lung perfusion from a single acquisition. • There is excellent agreement between DECT perfusion and scintigraphy in separating CTEPH and non-CTEPH patients.


Assuntos
Hipertensão Pulmonar/diagnóstico por imagem , Embolia Pulmonar/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Cintilografia de Ventilação/Perfusão/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Angiografia por Tomografia Computadorizada/métodos , Feminino , Humanos , Pulmão/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Relação Ventilação-Perfusão , Adulto Jovem
10.
PLoS One ; 12(11): e0188884, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29176897

RESUMO

BACKGROUND: The association of left ventricular remodeling (LVR) after myocardial infarction (MI) with the subsequent risk of heart failure (HF) and death has not been studied in patients receiving optimal secondary prevention. METHODS AND RESULTS: We performed a long-term clinical follow-up of patients included in 2 prospective multicentric studies on LVR after first anterior MI. At 1-year echocardiography, LVR (≥20% increase in end-diastolic volume from baseline to 1 year) occurred in 67/215 (31%) patients in cohort 1 and in 87/226 (38%) patients in cohort 2. The prescription rate of secondary prevention medications was very high (ß-blockers at 1 year: 90% and 95% for cohorts 1 and 2, respectively; angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers (ACE-I/ARB) at 1 year: 93% and 97% for cohorts 1 and 2, respectively). Median clinical follow-up after LVR assessment was 11.0 years in cohort 1 and 7.8 years in cohort 2. In both cohorts, LVR patients had a progressive increase in the risk of cardiovascular death or hospitalization for HF (p = 0.0007 in cohort 1 and 0.009 in cohort 2) with unadjusted hazard ratios of 2.52 [1.45-4.36] and 2.52 [1.23-5.17], respectively. Similar results were obtained when cardiovascular death was considered as an isolated endpoint. After adjustement on baseline characteristics including ejection fraction, the association with the composite endpoint was unchanged. CONCLUSION: In a context of a modern therapeutic management with a large prescription of evidence-based medications, LVR remains independently associated with HF and cardiovascular death at long-term follow-up after MI.


Assuntos
Infarto do Miocárdio/fisiopatologia , Padrões de Prática Médica , Remodelação Ventricular , Estudos de Coortes , Ecocardiografia , Determinação de Ponto Final , Feminino , Seguimentos , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/fisiopatologia , Hospitalização , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Prognóstico , Fatores de Tempo
11.
Int J Cardiol ; 245: 190-195, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28768580

RESUMO

BACKGROUND: Right ventricular (RV) systolic function is a powerful prognostic factor in patients with systolic heart failure. The accurate estimation of RV function remains difficult. The aim of the study was to determine the diagnostic accuracy of 2D-speckle tracking RV strain in patients with systolic heart failure, analyzing both free and posterolateral walls. METHODS: Seventy-six patients with dilated cardiopathy (left ventricular end-diastolic volume≥75ml/m2) and left ventricular ejection fraction≤45% had an analysis of the RV strain. Feasibility, reproducibility and diagnostic accuracy of RV strain were analyzed and compared to other echocardiographic parameters of RV function. RV dysfunction was defined as a RV ejection fraction≤40% measured by radionuclide angiography. RESULTS: RV strain feasibility was 93.9% for the free-wall and 79.8% for the posterolateral wall. RV strain reproducibility was good (intra-observer and inter-observer bias and limits of agreement of 0.16±1.2% [-2.2-2.5] and 0.84±2.4 [-5.5-3.8], respectively). Patients with left heart failure have a RV systolic dysfunction that can be unmasked by advanced echocardiographic imaging: mean RV strain was -21±5.7% in patients without RV dysfunction and -15.8±5.1% in patients with RV dysfunction (p=0.0001). Mean RV strain showed the highest diagnostic accuracy to predict depressed RVEF (area under the curve (AUC) 0.75) with moderate sensitivity (60.5%) but high specificity (87.5%) using a cutoff value of -16%. CONCLUSIONS: RV strain seems to be a promising and more efficient measure than previous RV echocardiographic parameters for the diagnosis of RV systolic dysfunction.


Assuntos
Ecocardiografia/métodos , Insuficiência Cardíaca Sistólica/diagnóstico por imagem , Insuficiência Cardíaca Sistólica/fisiopatologia , Angiografia Cintilográfica/métodos , Função Ventricular Direita/fisiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Volume Sistólico/fisiologia , Disfunção Ventricular Direita/diagnóstico por imagem , Disfunção Ventricular Direita/fisiopatologia
12.
Nat Struct Mol Biol ; 24(8): 652-657, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28671667

RESUMO

The sarcomere-based structure of muscles is conserved among vertebrates; however, vertebrate muscle physiology is extremely diverse. A molecular explanation for this diversity and its evolution has not been proposed. We use phylogenetic analyses and single-molecule force spectroscopy (smFS) to investigate the mechanochemical evolution of titin, a giant protein responsible for the elasticity of muscle filaments. We resurrect eight-domain fragments of titin corresponding to the common ancestors to mammals, sauropsids, and tetrapods, which lived 105-356 Myr ago, and compare them with titin fragments from some of their modern descendants. We demonstrate that the resurrected titin molecules are rich in disulfide bonds and display high mechanical stability. These mechanochemical elements have changed over time, creating a paleomechanical trend that seems to correlate with animal body size, allowing us to estimate the sizes of extinct species. We hypothesize that mechanical adjustments in titin contributed to physiological changes that allowed the muscular development and diversity of modern tetrapods.


Assuntos
Fenômenos Químicos , Conectina/genética , Conectina/metabolismo , Evolução Molecular , Fenômenos Mecânicos , Animais , Dissulfetos/análise , Filogenia , Análise Espectral , Vertebrados
13.
J Biol Chem ; 292(32): 13374-13380, 2017 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-28642368

RESUMO

Disulfide bonds play a crucial role in proteins, modulating their stability and constraining their conformational dynamics. A particularly important case is that of proteins that need to withstand forces arising from their normal biological function and that are often disulfide bonded. However, the influence of disulfides on the overall mechanical stability of proteins is poorly understood. Here, we used single-molecule force spectroscopy (smFS) to study the role of disulfide bonds in different mechanical proteins in terms of their unfolding forces. For this purpose, we chose the pilus protein FimG from Gram-negative bacteria and a disulfide-bonded variant of the I91 human cardiac titin polyprotein. Our results show that disulfide bonds can alter the mechanical stability of proteins in different ways depending on the properties of the system. Specifically, disulfide-bonded FimG undergoes a 30% increase in its mechanical stability compared with its reduced counterpart, whereas the unfolding force of I91 domains experiences a decrease of 15% relative to the WT form. Using a coarse-grained simulation model, we rationalized that the increase in mechanical stability of FimG is due to a shift in the mechanical unfolding pathway. The simple topology-based explanation suggests a neutral effect in the case of titin. In summary, our results indicate that disulfide bonds in proteins act in a context-dependent manner rather than simply as mechanical lockers, underscoring the importance of considering disulfide bonds both computationally and experimentally when studying the mechanical properties of proteins.


Assuntos
Conectina/química , Cisteína/química , Cistina/química , Proteínas de Escherichia coli/química , Proteínas de Fímbrias/química , Modelos Moleculares , Substituição de Aminoácidos , Conectina/genética , Conectina/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Proteínas de Fímbrias/genética , Proteínas de Fímbrias/metabolismo , Humanos , Simulação de Dinâmica Molecular , Mutação , Oxirredução , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Conformação Proteica , Engenharia de Proteínas , Domínios e Motivos de Interação entre Proteínas , Estabilidade Proteica , Desdobramento de Proteína , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Imagem Individual de Molécula
15.
ESC Heart Fail ; 4(1): 75-77, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28217316

RESUMO

A 72-year-old woman with history of breast cancer only treated surgically was referred to our department for pulmonary hypertension (PH) suspicion. Echocardiogram revealed elevated right ventricular systolic pressure. Computed tomography (CT) angiogram showed no pulmonary embolism (PE), but lung scan revealed two ventilation-perfusion mismatch areas. Right cardiac catheterization established precapillary PH. Despite treatment with PH specific therapy (sildenafil, ambrisentan, and epoprostenol), her condition worsened rapidly with acute right heart failure (RHF). She died 22 days after admission. Post-mortem microscopic examination showed a rare combination of PH etiologies consistent with metastasis of breast cancer in pulmonary vasculature including the rare pulmonary tumour thrombotic microangiopathy (PTTM).

16.
Arch Cardiovasc Dis ; 108(6-7): 375-84, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25921840

RESUMO

BACKGROUND: Severe pulmonary hypertension is a usual contraindication to heart transplantation. A few studies have found that sildenafil has a favourable effect on haemodynamic variables in patients with severe left ventricular systolic dysfunction. AIM: To report our clinical experience of sildenafil in patients with left ventricular systolic dysfunction and severe pulmonary hypertension. METHODS: All patients underwent echocardiography, radionuclide angiography, a cardiopulmonary exercise test and right heart catheterization before and after treatment with sildenafil. All patients were clinically stable and were receiving maximal tolerated doses of recommended drugs. RESULTS: We included 18 patients, with a mean±standard deviation age of 47±13 years. After a median of 8.7 months (interquartile range, 4.4-13.5 months) on sildenafil, there was a significant improvement in New York Heart Association classification (P=0.02) and mean right ventricular ejection fraction (from 26±7% to 30±9%; P=0.008), with a decrease in the VE/VCO2 slope (from 52±11 to 44±11; P=0.009) and in pulmonary vascular resistance (from 5.3±1.9 Wood units to 3.3±1.8 Wood units; P=0.01). During follow-up, three patients had urgent heart transplantation, two had non-urgent transplantation and six had left ventricular assist device implantation. All patients with pulmonary vascular resistance<3 Wood units after sildenafil were alive, compared with four in the other subgroup (44% survival). CONCLUSION: In patients with pulmonary hypertension related to left ventricular systolic dysfunction, sildenafil seems to improve cardiac haemodynamics.


Assuntos
Transplante de Coração , Hipertensão Pulmonar/tratamento farmacológico , Citrato de Sildenafila/uso terapêutico , Vasodilatadores/uso terapêutico , Disfunção Ventricular Esquerda/complicações , Adulto , Cateterismo Cardíaco , Fármacos Cardiovasculares/uso terapêutico , Terapia Combinada , Dobutamina/uso terapêutico , Avaliação de Medicamentos , Feminino , Seguimentos , Hemodinâmica , Estudo Historicamente Controlado , Humanos , Hipertensão Pulmonar/diagnóstico por imagem , Hipertensão Pulmonar/etiologia , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Cintilografia , Estudos Retrospectivos , Citrato de Sildenafila/farmacologia , Volume Sistólico/efeitos dos fármacos , Sístole , Ultrassonografia , Vasodilatadores/farmacologia , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/tratamento farmacológico , Disfunção Ventricular Esquerda/cirurgia , Listas de Espera
20.
Circ Heart Fail ; 7(3): 434-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24563449

RESUMO

BACKGROUND: Some patients with left ventricular systolic dysfunction (LVSD) have a dramatic improvement in left ventricular ejection fraction (LVEF) after ß-blockade. No study has analyzed the long-term echocardiographic and clinical follow-up of this subgroup of patients. METHODS AND RESULTS: We included in this analysis 174 consecutive patients with LVSD who had an LVEF≥45% after ß-blockade. We performed a long-term echocardiographic follow-up (median 7.7 [4-9.9] years) and clinical follow-up (median 9.2 [7.2-10.8] years). LVEF improved from 33±8% to 54±6% after ß-blockade (P<0.0001). At the last echocardiographic evaluation, 26% of the patients had an LVEF<45% (mean±SD: 34±6%), whereas 74% still had an LVEF≥45% (mean±SD: 54±6%). Independent predictors of LVEF deterioration were a low LVEF, a high left ventricular end-diastolic diameter and a low heart rate after ß-blockade, and the presence of a complete left bundle-branch block. In the overall study population, survival rates were 90% at 5 years and 75% at 10 years. Cardiovascular death rate was 9%, noncardiovascular death rate was 11%, and unknown death rate was 3%. Patients with subsequent LVEF deterioration had a higher cardiovascular mortality compared with patients with sustained recovered LVEF (22% versus 4%). CONCLUSIONS: The long-term survival of patients with LVSD and with near-normal LVEF after ß-blockade is good. However, a quarter of these patients may experience a subsequent degradation of LVEF. These patients are at higher risk of cardiovascular mortality.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/fisiopatologia , Volume Sistólico/fisiologia , Disfunção Ventricular Esquerda/tratamento farmacológico , Disfunção Ventricular Esquerda/fisiopatologia , Antagonistas Adrenérgicos beta/farmacologia , Adulto , Idoso , Comorbidade , Ecocardiografia , Feminino , Seguimentos , Insuficiência Cardíaca/epidemiologia , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Volume Sistólico/efeitos dos fármacos , Taxa de Sobrevida , Sístole/fisiologia , Fatores de Tempo , Resultado do Tratamento , Disfunção Ventricular Esquerda/epidemiologia
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