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2.
JACC CardioOncol ; 6(2): 217-232, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38774018

RESUMO

Background: Anthracycline-induced cardiotoxicity (AIC) debilitates quality of life in cancer survivors. Serial characterizations are lacking of the molecular processes occurring with AIC. Objectives: The aim of this study was to characterize AIC progression in a mouse model from early (subclinical) to advanced heart failure stages, with an emphasis on cardiac metabolism and mitochondrial structure and function. Methods: CD1 mice received 5 weekly intraperitoneal doxorubicin injections (5 mg/kg) and were followed by serial echocardiography for 15 weeks. At 1, 9, and 15 weeks after the doxorubicin injections, mice underwent fluorodeoxyglucose positron emission tomography, and hearts were extracted for microscopy and molecular analysis. Results: Cardiac atrophy was evident at 1 week post-doxorubicin (left ventricular [LV] mass 117 ± 26 mg vs 97 ± 25 mg at baseline and 1 week, respectively; P < 0.001). Cardiac mass nadir was observed at week 3 post-doxorubicin (79 ± 16 mg; P = 0.002 vs baseline), remaining unchanged thereafter. Histology confirmed significantly reduced cardiomyocyte area (167 ± 19 µm2 in doxorubicin-treated mice vs 211 ± 26 µm2 in controls; P = 0.004). LV ejection fraction declined from week 6 post-doxorubicin (49% ± 9% vs 61% ± 9% at baseline; P < 0.001) until the end of follow-up at 15 weeks (43% ± 8%; P < 0.001 vs baseline). At 1 week post-doxorubicin, when LV ejection fraction remained normal, reduced cardiac metabolism was evident from down-regulated markers of fatty acid oxidation and glycolysis. Metabolic impairment continued to the end of follow-up in parallel with reduced mitochondrial adenosine triphosphate production. A transient early up-regulation of nutrient-sensing and mitophagy markers were observed, which was associated with mitochondrial enlargement. Later stages, when mitophagy was exhausted, were characterized by overt mitochondrial fragmentation. Conclusions: Cardiac atrophy, global hypometabolism, early transient-enhanced mitophagy, biogenesis, and nutrient sensing constitute candidate targets for AIC prevention.

3.
Basic Res Cardiol ; 119(3): 419-433, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38536505

RESUMO

Right ventricular (RV) failure remains the strongest determinant of survival in pulmonary hypertension (PH). We aimed to identify relevant mechanisms, beyond pressure overload, associated with maladaptive RV hypertrophy in PH. To separate the effect of pressure overload from other potential mechanisms, we developed in pigs two experimental models of PH (M1, by pulmonary vein banding and M2, by aorto-pulmonary shunting) and compared them with a model of pure pressure overload (M3, pulmonary artery banding) and a sham-operated group. Animals were assessed at 1 and 8 months by right heart catheterization, cardiac magnetic resonance and blood sampling, and myocardial tissue was analyzed. Plasma unbiased proteomic and metabolomic data were compared among groups and integrated by an interaction network analysis. A total of 33 pigs completed follow-up (M1, n = 8; M2, n = 6; M3, n = 10; and M0, n = 9). M1 and M2 animals developed PH and reduced RV systolic function, whereas animals in M3 showed increased RV systolic pressure but maintained normal function. Significant plasma arginine and histidine deficiency and complement system activation were observed in both PH models (M1&M2), with additional alterations to taurine and purine pathways in M2. Changes in lipid metabolism were very remarkable, particularly the elevation of free fatty acids in M2. In the integrative analysis, arginine-histidine-purines deficiency, complement activation, and fatty acid accumulation were significantly associated with maladaptive RV hypertrophy. Our study integrating imaging and omics in large-animal experimental models demonstrates that, beyond pressure overload, metabolic alterations play a relevant role in RV dysfunction in PH.


Assuntos
Modelos Animais de Doenças , Hipertensão Pulmonar , Hipertrofia Ventricular Direita , Metabolômica , Proteômica , Animais , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/fisiopatologia , Hipertensão Pulmonar/diagnóstico por imagem , Hipertrofia Ventricular Direita/metabolismo , Hipertrofia Ventricular Direita/fisiopatologia , Hipertrofia Ventricular Direita/diagnóstico por imagem , Função Ventricular Direita , Remodelação Ventricular , Sus scrofa , Suínos , Masculino
4.
Antioxidants (Basel) ; 13(1)2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38247530

RESUMO

While reperfusion, or restoration of coronary blood flow in acute myocardial infarction, is a requisite for myocardial salvage, it can paradoxically induce a specific damage known as ischemia/reperfusion (I/R) injury. Our understanding of the precise pathophysiological molecular alterations leading to I/R remains limited. In this study, we conducted a comprehensive and unbiased time-course analysis of post-translational modifications (PTMs) in the post-reperfused myocardium of two different animal models (pig and mouse) and evaluated the effect of two different cardioprotective therapies (ischemic preconditioning and neutrophil depletion). In pigs, a first wave of irreversible oxidative damage was observed at the earliest reperfusion time (20 min), impacting proteins essential for cardiac contraction. A second wave, characterized by irreversible oxidation on different residues and reversible Cys oxidation, occurred at late stages (6-12 h), affecting mitochondrial, sarcomere, and inflammation-related proteins. Ischemic preconditioning mitigated the I/R damage caused by the late oxidative wave. In the mouse model, the two-phase pattern of oxidative damage was replicated, and neutrophil depletion mitigated the late wave of I/R-related damage by preventing both Cys reversible oxidation and irreversible oxidation. Altogether, these data identify protein PTMs occurring late after reperfusion as an actionable therapeutic target to reduce the impact of I/R injury.

5.
JACC CardioOncol ; 5(6): 715-731, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38205010

RESUMO

Despite improvements in cancer survival, cancer therapy-related cardiovascular toxicity has risen to become a prominent clinical challenge. This has led to the growth of the burgeoning field of cardio-oncology, which aims to advance the cardiovascular health of cancer patients and survivors, through actionable and translatable science. In these Global Cardio-Oncology Symposium 2023 scientific symposium proceedings, we present a focused review on the mechanisms that contribute to common cardiovascular toxicities discussed at this meeting, the ongoing international collaborative efforts to improve patient outcomes, and the bidirectional challenges of translating basic research to clinical care. We acknowledge that there are many additional therapies that are of significance but were not topics of discussion at this symposium. We hope that through this symposium-based review we can highlight the knowledge gaps and clinical priorities to inform the design of future studies that aim to prevent and mitigate cardiovascular disease in cancer patients and survivors.

6.
Front Vet Sci ; 9: 919454, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36353254

RESUMO

Large animal models of acute myocardial infarction (AMI) play a crucial role in translating novel therapeutic approaches to patients as denoted by their use in the right-before-human testing platform. At present, the porcine model of AMI is used most frequently as it mimics the human condition and its anatomopathological features accurately. We want to describe to, and share with, the translational research community our experience of how different anaesthetic protocols (sevoflurane, midazolam, ketamine+xylazine+midazolam, and propofol) and pig breeds [Large White and Landrace x Large White (LLW)] can dramatically modify the outcomes of a well-established porcine model of closed-chest AMI. Our group has extensive experience with the porcine model of reperfused AMI and, over time, we reduced the time of ischaemia used to induce the disease from 90 to 50 min to increase the salvageable myocardium for cardioprotection studies. For logistical reasons, we changed both the anaesthetic protocol and the pig breed used, but these resulted in a dramatic reduction in the size of the myocardial infarct, to almost zero in some cases (sevoflurane, 50-min ischaemia, LLW, 2.4 ± 3.9% infarct size), and the cardiac function was preserved. Therefore, we had to re-validate the model by returning to 90 min of ischaemia. Here, we report the differences in infarct size and cardiac function, measured by different modalities, for each combination of anaesthetic protocol and pig breed we have used. Furthermore, we discuss these combinations and the limited literature pertaining to how these two factors influence cardiac function and infarct size in the porcine model of AMI.

7.
Cardiovasc Res ; 118(2): 531-541, 2022 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-33605403

RESUMO

AIMS: The aim of this study was to study changes in coronary microcirculation status during and after several cycles of anthracycline treatment. METHODS AND RESULTS: Large-white male pigs (n=40) were included in different experimental protocols (ExPr.) according to anthracycline cumulative exposure [0.45 mg/kg intracoronary (IC) doxorubicin per injection] and follow-up: control (no doxorubicin); single injection and sacrifice either at 48 h (ExPr. 1) or 2 weeks (ExPr. 2); 3 injections 2 weeks apart (low cumulative dose) and sacrifice either 2 weeks (ExPr. 3) or 12 weeks (ExPr. 4) after third injection; five injections 2 weeks apart (high cumulative dose) and sacrifice 8 weeks after fifth injection (ExPr. 5). All groups were assessed by serial cardiac magnetic resonance (CMR) to quantify perfusion and invasive measurement of coronary flow reserve (CFR). At the end of each protocol, animals were sacrificed for ex vivo analyses. Vascular function was further evaluated by myography in explanted coronary arteries of pigs undergoing ExPr. 3 and controls. A single doxorubicin injection had no impact on microcirculation status, excluding a direct chemical toxicity. A series of five fortnightly doxorubicin injections (high cumulative dose) triggered a progressive decline in microcirculation status, evidenced by reduced CMR-based myocardial perfusion and CFR-measured impaired functional microcirculation. In the high cumulative dose regime (ExPr. 5), microcirculation changes appeared long before any contractile defect became apparent. Low cumulative doxorubicin dose (three bi-weekly injections) was not associated with any contractile defect across long-term follow-up, but provoked persistent microcirculation damage, evident soon after third dose injection. Histological and myograph evaluations confirmed structural damage to arteries of all calibres even in animals undergoing low cumulative dose regimes. Conversely, arteriole damage and capillary bed alteration occurred only after high cumulative dose regime. CONCLUSION: Serial in vivo evaluations of microcirculation status using state-of-the-art CMR and invasive CFR show that anthracyclines treatment is associated with progressive and irreversible damage to the microcirculation. This long-persisting damage is present even in low cumulative dose regimes, which are not associated with cardiac contractile deficits. Microcirculation damage might explain some of the increased incidence of cardiovascular events in cancer survivors who received anthracyclines without showing cardiac contractile defects.


Assuntos
Circulação Coronária , Vasos Coronários/fisiopatologia , Cardiopatias/fisiopatologia , Microcirculação , Microvasos/fisiopatologia , Animais , Antibióticos Antineoplásicos , Cardiotoxicidade , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/patologia , Modelos Animais de Doenças , Doxorrubicina , Cardiopatias/induzido quimicamente , Cardiopatias/diagnóstico por imagem , Cardiopatias/patologia , Imageamento por Ressonância Magnética , Masculino , Microvasos/diagnóstico por imagem , Microvasos/patologia , Imagem de Perfusão do Miocárdio , Sus scrofa , Fatores de Tempo
9.
Sci Rep ; 11(1): 18722, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34580343

RESUMO

Delayed gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) imaging requires novel and time-efficient approaches to characterize the myocardial substrate associated with ventricular arrhythmia in patients with ischemic cardiomyopathy. Using a translational approach in pigs and patients with established myocardial infarction, we tested and validated a novel 3D methodology to assess ventricular scar using custom transmural criteria and a semiautomatic approach to obtain transmural scar maps in ventricular models reconstructed from both 3D-acquired and 3D-upsampled-2D-acquired LGE-CMR images. The results showed that 3D-upsampled models from 2D LGE-CMR images provided a time-efficient alternative to 3D-acquired sequences to assess the myocardial substrate associated with ischemic cardiomyopathy. Scar assessment from 2D-LGE-CMR sequences using 3D-upsampled models was superior to conventional 2D assessment to identify scar sizes associated with the cycle length of spontaneous ventricular tachycardia episodes and long-term ventricular tachycardia recurrences after catheter ablation. This novel methodology may represent an efficient approach in clinical practice after manual or automatic segmentation of myocardial borders in a small number of conventional 2D LGE-CMR slices and automatic scar detection.


Assuntos
Cardiomiopatias/diagnóstico por imagem , Cicatriz/patologia , Taquicardia Ventricular/diagnóstico por imagem , Idoso , Animais , Arritmias Cardíacas/patologia , Cardiomiopatias/metabolismo , Cicatriz/diagnóstico por imagem , Biologia Computacional/métodos , Meios de Contraste , Feminino , Gadolínio/farmacologia , Ventrículos do Coração/fisiopatologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/fisiopatologia , Isquemia Miocárdica/patologia , Miocárdio/patologia , Recidiva , Suínos , Taquicardia Ventricular/fisiopatologia
10.
J Am Coll Cardiol ; 78(10): 1001-1011, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34474731

RESUMO

BACKGROUND: Severe coronavirus disease-2019 (COVID-19) can progress to an acute respiratory distress syndrome (ARDS), which involves alveolar infiltration by activated neutrophils. The beta-blocker metoprolol has been shown to ameliorate exacerbated inflammation in the myocardial infarction setting. OBJECTIVES: The purpose of this study was to evaluate the effects of metoprolol on alveolar inflammation and on respiratory function in patients with COVID-19-associated ARDS. METHODS: A total of 20 COVID-19 patients with ARDS on invasive mechanical ventilation were randomized to metoprolol (15 mg daily for 3 days) or control (no treatment). All patients underwent bronchoalveolar lavage (BAL) before and after metoprolol/control. The safety of metoprolol administration was evaluated by invasive hemodynamic and electrocardiogram monitoring and echocardiography. RESULTS: Metoprolol administration was without side effects. At baseline, neutrophil content in BAL did not differ between groups. Conversely, patients randomized to metoprolol had significantly fewer neutrophils in BAL on day 4 (median: 14.3 neutrophils/µl [Q1, Q3: 4.63, 265 neutrophils/µl] vs median: 397 neutrophils/µl [Q1, Q3: 222, 1,346 neutrophils/µl] in the metoprolol and control groups, respectively; P = 0.016). Metoprolol also reduced neutrophil extracellular traps content and other markers of lung inflammation. Oxygenation (PaO2:FiO2) significantly improved after 3 days of metoprolol treatment (median: 130 [Q1, Q3: 110, 162] vs median: 267 [Q1, Q3: 199, 298] at baseline and day 4, respectively; P = 0.003), whereas it remained unchanged in control subjects. Metoprolol-treated patients spent fewer days on invasive mechanical ventilation than those in the control group (15.5 ± 7.6 vs 21.9 ± 12.6 days; P = 0.17). CONCLUSIONS: In this pilot trial, intravenous metoprolol administration to patients with COVID-19-associated ARDS was safe, reduced exacerbated lung inflammation, and improved oxygenation. Repurposing metoprolol for COVID-19-associated ARDS appears to be a safe and inexpensive strategy that can alleviate the burden of the COVID-19 pandemic.


Assuntos
COVID-19/transmissão , Estado Terminal/terapia , Metoprolol/administração & dosagem , Pandemias , Respiração Artificial/métodos , SARS-CoV-2 , Antagonistas de Receptores Adrenérgicos beta 1/administração & dosagem , Adulto , Idoso , COVID-19/epidemiologia , Feminino , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos
12.
Cardiovasc Res ; 117(4): 1132-1143, 2021 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-32597960

RESUMO

AIMS: Anthracycline-induced cardiotoxicity (AIC) is a serious adverse effect among cancer patients. A central mechanism of AIC is irreversible mitochondrial damage. Despite major efforts, there are currently no effective therapies able to prevent AIC. METHODS AND RESULTS: Forty Large-White pigs were included. In Study 1, 20 pigs were randomized 1:1 to remote ischaemic preconditioning (RIPC, 3 cycles of 5 min leg ischaemia followed by 5 min reperfusion) or no pretreatment. RIPC was performed immediately before each intracoronary doxorubicin injections (0.45 mg/kg) given at Weeks 0, 2, 4, 6, and 8. A group of 10 pigs with no exposure to doxorubicin served as healthy controls. Pigs underwent serial cardiac magnetic resonance (CMR) exams at baseline and at Weeks 6, 8, 12, and 16, being sacrifice after that. In Study 2, 10 new pigs received 3 doxorubicin injections (with/out preceding RIPC) and were sacrificed at week 6. In Study 1, left ventricular ejection fraction (LVEF) depression was blunted animals receiving RIPC before doxorubicin (RIPC-Doxo), which had a significantly higher LVEF at Week 16 than doxorubicin treated pigs that received no pretreatment (Untreated-Doxo) (41.5 ± 9.1% vs. 32.5 ± 8.7%, P = 0.04). It was mainly due to conserved regional contractile function. In Study 2, transmission electron microscopy (TEM) at Week 6 showed fragmented mitochondria with severe morphological abnormalities in Untreated-Doxo pigs, together with upregulation of fission and autophagy proteins. At the end of the 16-week Study 1 protocol, TEM revealed overt mitochondrial fragmentation with structural fragmentation in Untreated-Doxo pigs, whereas interstitial fibrosis was less severe in RIPC+Doxo pigs. CONCLUSION: In a translatable large-animal model of AIC, RIPC applied immediately before each doxorubicin injection resulted in preserved cardiac contractility with significantly higher long-term LVEF and less cardiac fibrosis. RIPC prevented mitochondrial fragmentation and dysregulated autophagy from AIC early stages. RIPC is a promising intervention for testing in clinical trials in AIC.


Assuntos
Cardiopatias/prevenção & controle , Membro Posterior/irrigação sanguínea , Precondicionamento Isquêmico , Mitocôndrias Cardíacas/ultraestrutura , Miocárdio/ultraestrutura , Volume Sistólico , Função Ventricular Esquerda , Remodelação Ventricular , Animais , Antibióticos Antineoplásicos , Autofagia , Proteínas Relacionadas à Autofagia/metabolismo , Cardiotoxicidade , Modelos Animais de Doenças , Doxorrubicina , Fibrose , Cardiopatias/induzido quimicamente , Cardiopatias/patologia , Cardiopatias/fisiopatologia , Imagem Cinética por Ressonância Magnética , Masculino , Mitocôndrias Cardíacas/metabolismo , Dinâmica Mitocondrial , Miocárdio/metabolismo , Fluxo Sanguíneo Regional , Sus scrofa , Fatores de Tempo
13.
Basic Res Cardiol ; 115(5): 55, 2020 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-32748088

RESUMO

Early metoprolol administration protects against myocardial ischemia-reperfusion injury, but its effect on infarct size progression (ischemic injury) is unknown. Eight groups of pigs (total n = 122) underwent coronary artery occlusion of varying duration (20, 25, 30, 35, 40, 45, 50, or 60 min) followed by reperfusion. In each group, pigs were randomized to i.v. metoprolol (0.75 mg/kg) or vehicle (saline) 20 min after ischemia onset. The primary outcome measure was infarct size (IS) on day7 cardiac magnetic resonance (CMR) normalized to area at risk (AAR, measured by perfusion computed tomography [CT] during ischemia). Metoprolol treatment reduced overall mortality (10% vs 26%, p = 0.03) and the incidence and number of primary ventricular fibrillations during infarct induction. In controls, IS after 20-min ischemia was ≈ 5% of the area AAR. Thereafter, IS progressed exponentially, occupying almost all the AAR after 35 min of ischemia. Metoprolol injection significantly reduced the slope of IS progression (p = 0.004 for final IS). Head-to-head comparison (metoprolol treated vs vehicle treated) showed statistically significant reductions in IS at 30, 35, 40, and 50-min reperfusion. At 60-min reperfusion, IS was 100% of AAR in both groups. Despite more prolonged ischemia, metoprolol-treated pigs reperfused at 50 min had smaller infarcts than control pigs undergoing ischemia for 40 or 45 min and similar-sized infarcts to those undergoing 35-min ischemia. Day-45 LVEF was higher in metoprolol-treated vs vehicle-treated pigs (41.6% vs 36.5%, p = 0.008). In summary, metoprolol administration early during ischemia attenuates IS progression and reduces the incidence of primary ventricular fibrillation. These data identify metoprolol as an intervention ideally suited to the treatment of STEMI patients identified early in the course of infarction and requiring long transport times before primary angioplasty.


Assuntos
Antagonistas de Receptores Adrenérgicos beta 1/administração & dosagem , Metoprolol/administração & dosagem , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio/patologia , Infarto do Miocárdio com Supradesnível do Segmento ST/tratamento farmacológico , Administração Intravenosa , Animais , Técnicas de Imagem Cardíaca , Progressão da Doença , Avaliação Pré-Clínica de Medicamentos , Imageamento por Ressonância Magnética , Masculino , Traumatismo por Reperfusão Miocárdica/diagnóstico por imagem , Traumatismo por Reperfusão Miocárdica/patologia , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico por imagem , Infarto do Miocárdio com Supradesnível do Segmento ST/patologia , Suínos , Fatores de Tempo
14.
MAGMA ; 33(6): 865-876, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32410103

RESUMO

OBJECTIVES: To propose and validate a novel imaging sequence that uses a single breath-hold whole-heart 3D T1 saturation recovery compressed SENSE rapid acquisition (SACORA) at 3T. METHODS: The proposed sequence combines flexible saturation time sampling, compressed SENSE, and sharing of saturation pulses between two readouts acquired at different RR intervals. The sequence was compared with a 3D saturation recovery single-shot acquisition (SASHA) implementation with phantom and in vivo experiments (pre and post contrast; 7 pigs) and was validated against the reference inversion recovery spin echo (IR-SE) sequence in phantom experiments. RESULTS: Phantom experiments showed that the T1 maps acquired by 3D SACORA and 3D SASHA agree well with IR-SE. In vivo experiments showed that the pre-contrast and post-contrast T1 maps acquired by 3D SACORA are comparable to the corresponding 3D SASHA maps, despite the shorter acquisition time (15s vs. 188s, for a heart rate of 60 bpm). Mean septal pre-contrast T1 was 1453 ± 44 ms with 3D SACORA and 1460 ± 60 ms with 3D SASHA. Mean septal post-contrast T1 was 824 ± 66 ms and 824 ± 60 ms. CONCLUSION: 3D SACORA acquires 3D T1 maps in 15 heart beats (heart rate, 60 bpm) at 3T. In addition to its short acquisition time, the sequence achieves good T1 estimation precision and accuracy.


Assuntos
Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Animais , Suspensão da Respiração , Coração/diagnóstico por imagem , Imagens de Fantasmas , Reprodutibilidade dos Testes , Suínos
15.
Basic Res Cardiol ; 115(3): 33, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32291522

RESUMO

Nonrevascularizable coronary artery disease is a frequent cause of hibernating myocardium leading to heart failure (HF). Currently, there is a paucity of therapeutic options for patients with this condition. There is a lack of animal models resembling clinical features of hibernating myocardium. Here we present a large animal model of hibernating myocardium characterized by serial multimodality imaging. Yucatan minipigs underwent a surgical casein ameroid implant around the proximal left anterior descending coronary artery (LAD), resulting in a progressive obstruction of the vessel. Pigs underwent serial multimodality imaging including invasive coronary angiography, cardiac magnetic resonance (CMR), and hybrid 18F-Fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT). A total of 43 pigs were operated on and were followed for 120 ± 37 days with monthly multimodality imaging. 24 pigs (56%) died during the follow-up. Severe LAD luminal stenosis was documented in all survivors. In the group of 19 long-term survivors, 17 (90%) developed left ventricular systolic dysfunction [median LVEF of 35% (IQR 32.5-40.5%)]. In 17/17, at-risk territory was viable on CMR and 14 showed an increased glucose uptake in the at-risk myocardium on 18FDG-PET/CT. The present pig model resembles most of the human hibernated myocardium characteristics and associated heart failure (systolic dysfunction, viable myocardium, and metabolic switch to glucose). This human-like model might be used to test novel interventions for nonrevascularizable coronary artery disease and ischemia heart failure as a previous stage to clinical trials.


Assuntos
Modelos Animais de Doenças , Miocárdio Atordoado/patologia , Animais , Angiografia Coronária/métodos , Insuficiência Cardíaca/patologia , Imagem Multimodal/métodos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Suínos , Porco Miniatura , Pesquisa Translacional Biomédica
17.
J Nucl Cardiol ; 27(4): 1249-1260, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-30927149

RESUMO

BACKGROUND: Here we evaluated the feasibility of PET with Gallium-68 (68Ga)-labeled DOTA for non-invasive assessment of myocardial blood flow (MBF) and extracellular volume fraction (ECV) in a pig model of myocardial infarction. We also aimed to validate MBF measurements using microspheres as a gold standard in healthy pigs. METHODS: 8 healthy pigs underwent three sequential 68Ga-DOTA-PET/CT scans at rest and during pharmacological stress with simultaneous injection of fluorescent microspheres to validate MBF measurements. Myocardial infarction was induced in 5 additional pigs, which underwent 68Ga-DOTA-PET/CT examinations 7-days after reperfusion. Dynamic PET images were reconstructed and fitted to obtain MBF and ECV parametric maps. RESULTS: MBF assessed with 68Ga-DOTA-PET showed good correlation (y = 0.96x + 0.11, r = 0.91) with that measured with microspheres. MBF values obtained with 68Ga-DOTA-PET in the infarcted area (LAD, left anterior descendant) were significantly reduced in comparison to remote ones LCX (left circumflex artery, P < 0.0001) and RCA (right coronary artery, P < 0.0001). ECV increased in the infarcted area (P < 0.0001). CONCLUSION: 68Ga-DOTA-PET allowed non-invasive assessment of MBF and ECV in pigs with myocardial infarction and under rest-stress conditions. This technique could provide wide access to quantitative measurement of both MBF and ECV with PET imaging.


Assuntos
Circulação Coronária/fisiologia , Radioisótopos de Gálio , Compostos Heterocíclicos com 1 Anel , Infarto do Miocárdio/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Animais , Autorradiografia , Estudos de Viabilidade , Feminino , Masculino , Suínos
18.
Eur Heart J Cardiovasc Imaging ; 21(9): 1031-1038, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31848573

RESUMO

AIMS: To assess whether R2* is more accurate than T2* for the detection of intramyocardial haemorrhage (IMH) and to evaluate whether T2' (or R2') is less affected by oedema than T2* (R2*), and thus more suitable for the accurate identification of post-myocardial infarction (MI) IMH. METHODS AND RESULTS: Reperfused anterior MI was performed in 20 pigs, which were sacrificed at 120 min, 24 h, 4 days, and 7 days. At each time point, cardiac magnetic resonance (CMR) T2- and T2*-mapping scans were recorded, and myocardial tissue samples were collected to quantify IMH and myocardial water content. After normalization by the number of red blood cells in remote tissue, histological IMH increased 5.2-fold, 10.7-fold, and 4.1-fold at Days 1, 4, and 7, respectively. The presence of IMH was correlated more strongly with R2* (r = 0.69; P = 0.013) than with T2* (r = -0.50; P = 0.085). The correlation with IMH was even stronger for R2' (r = 0.72; P = 0.008). For myocardial oedema, the correlation was stronger for R2* (r = -0.63; P = 0.029) than for R2' (r = -0.50; P = 0.100). Multivariate linear regressions confirmed that R2* values were significantly explained by both IMH and oedema, whereas R2' values were mostly explained by histological IMH (P = 0.024) and were little influenced by myocardial oedema (P = 0.262). CONCLUSION: Using CMR mapping with histological validation in a pig model of reperfused MI, R2'more accurately detected IMH and was less influenced by oedema than R2* (and T2*). Further studies are needed to elucidate whether R2' is also better suited for the characterization of post-MI IMH in the clinical setting.


Assuntos
Hemorragia , Imagem Cinética por Ressonância Magnética , Infarto do Miocárdio , Animais , Hemorragia/diagnóstico por imagem , Hemorragia/etiologia , Imageamento por Ressonância Magnética , Infarto do Miocárdio/complicações , Infarto do Miocárdio/diagnóstico por imagem , Miocárdio , Suínos
20.
Cell Discov ; 5: 16, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30911407

RESUMO

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare genetic disorder for which no cure exists. The disease is characterized by premature aging and inevitable death in adolescence due to cardiovascular complications. Most HGPS patients carry a heterozygous de novo LMNA c.1824C > T mutation, which provokes the expression of a dominant-negative mutant protein called progerin. Therapies proven effective in HGPS-like mouse models have yielded only modest benefit in HGPS clinical trials. To overcome the gap between HGPS mouse models and patients, we have generated by CRISPR-Cas9 gene editing the first large animal model for HGPS, a knockin heterozygous LMNA c.1824C > T Yucatan minipig. Like HGPS patients, HGPS minipigs endogenously co-express progerin and normal lamin A/C, and exhibit severe growth retardation, lipodystrophy, skin and bone alterations, cardiovascular disease, and die around puberty. Remarkably, the HGPS minipigs recapitulate critical cardiovascular alterations seen in patients, such as left ventricular diastolic dysfunction, altered cardiac electrical activity, and loss of vascular smooth muscle cells. Our analysis also revealed reduced myocardial perfusion due to microvascular damage and myocardial interstitial fibrosis, previously undescribed readouts potentially useful for monitoring disease progression in patients. The HGPS minipigs provide an appropriate preclinical model in which to test human-size interventional devices and optimize candidate therapies before advancing to clinical trials, thus accelerating the development of effective applications for HGPS patients.

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