RESUMO
Adaptive equalization is crucial in mitigating distortions and compensating for frequency response variations in communication systems. It aims to enhance signal quality by adjusting the characteristics of the received signal. Particle swarm optimization (PSO) algorithms have shown promise in optimizing the tap weights of the equalizer. However, there is a need to enhance the optimization capabilities of PSO further to improve the equalization performance. This paper provides a comprehensive study of the issues and challenges of adaptive filtering by comparing different variants of PSO and analyzing the performance by combining PSO with other optimization algorithms to achieve better convergence, accuracy, and adaptability. Traditional PSO algorithms often suffer from high computational complexity and slow convergence rates, limiting their effectiveness in solving complex optimization problems. To address these limitations, this paper proposes a set of techniques aimed at reducing the complexity and accelerating the convergence of PSO.
RESUMO
BACKGROUND: With high-sensitivity troponin testing, approximately a third of patients presenting to emergency departments (EDs) with suspected acute coronary syndromes will have mildly abnormal values. However, data regarding rest-stress myocardial perfusion imaging (MPI) in these patients are limited. We hypothesize that stress testing is safe and that the yield for detecting myocardial ischemia is associated with risk stratification by the HEART score. METHODS AND RESULTS: We conducted a retrospective cohort study of consecutive patients referred for rest-stress MPI with mildly abnormal high-sensitivity troponin T (hs-cTn) values. Outcomes were adverse events related to stress MPI, defined as myocardial infarction or ventricular tachyarrhythmia, and the presence of ischemia, defined as a reversible perfusion defect. Among 213 patients, the median age was 67, most were male (61.5%, n = 131), and prior CAD was common (53.5%, n = 114). Myocardial ischemia was present in 13.6% (n = 29), and there were no adverse events attributable to stress MPI. A higher HEART score was associated with myocardial ischemia (Odds Ratio [OR] 1.50, 95% Confidence Interval [CI] 1.08 to 2.08, P = .002). CONCLUSION: Rest-stress MPI appears safe in patients with mildly abnormal hs-cTn values, and the yield for detecting ischemia is associated with the HEART score, though further validation studies are needed.
Assuntos
Teste de Esforço/métodos , Isquemia Miocárdica/sangue , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/fisiopatologia , Imagem de Perfusão do Miocárdio/métodos , Troponina/sangue , Idoso , Estudos de Coortes , Serviço Hospitalar de Emergência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Descanso , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
The outcomes of hospitalization in the Fontan population have not been specifically studied. The purpose of this study was to describe outcomes of hospitalization (frequency and indications for hospitalization, and in-hospital mortality) in this population and to determine how these outcomes differ from those of other adults with congenital heart disease (CHD). METHODS: This was a retrospective study of adult Fontan patients hospitalized at Mayo Clinic Rochester in 1990-2015. We selected age- and gender-matched control group of patients with repaired CHD and biventricular circulation hospitalized within the study period. RESULTS: A total of 367 Fontan patients (age 31±7 years and 259 [71%] with atriopulmonary Fontan) had 853 hospital admissions in 4 years (58 hospitalizations per 100 patient-years). The most common indications were arrhythmia (n=188, 22%), heart failure (n=169, 20%), and cardiac surgery (n=133, 16%). Overall in-hospital mortality was 4% (n=38), and the highest in-hospital mortality occurred in patients hospitalized for cardiac surgery (n=15, 11%) and heart failure (n=13, 8%). In comparison to the repaired CHD and biventricular circulation group, the Fontan group had more frequent hospitalizations (22 vs 58 per 100 patient-years, P<.001) and higher overall in-hospital mortality (1% vs 5%, P<.001), mortality after cardiac surgery (2% vs 11%, P=.01), and mortality for heart failure-related hospitalizations (2% vs 8%, P=.04). CONCLUSIONS: Adults with Fontan palliation had more frequent hospitalization and in-hospital mortality compared to the rest of the CHD population. Arrhythmia and heart failure were the most common indications for hospitalization. Perhaps optimal management of heart failure and arrhythmia may improve outcomes in this population.
Assuntos
Técnica de Fontan/métodos , Insuficiência Cardíaca/terapia , Hospitalização/estatística & dados numéricos , Avaliação de Resultados em Cuidados de Saúde , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Centros Médicos Acadêmicos , Adulto , Análise de Variância , Estudos de Casos e Controles , Feminino , Técnica de Fontan/efeitos adversos , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Incidência , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Minnesota , Cuidados Paliativos/métodos , Valores de Referência , Estudos Retrospectivos , Medição de Risco , Estatísticas não ParamétricasRESUMO
BACKGROUND: Transcatheter closure of patent foramen ovale (PFO) after cryptogenic stroke has long been a contentious issue. Herein, we pool aggregate data examining safety and efficacy of transcatheter closure of PFO compared with medical therapy following initial cryptogenic stroke. METHODS: We searched for randomized clinical trials (RCT) that compared device closure with medical management and reported on subsequent stroke and adverse events. Stroke was considered as the primary efficacy endpoint, whereas bleeding and atrial fibrillation were considered primary safety endpoints. Data were pooled by the random effects model and I2 was used to assess heterogeneity. RESULTS: A total of 5 RCT investigating 3630 patients met inclusion criteria. Pooled analysis revealed that device closure compared to medical management was associated with a significant reduction in stroke (RR=0.3, 95% CI=0.02-0.57). There was, however, a significant increase in atrial arrhythmias with device therapy (RR=4.8, 95% CI=2.2-10.7). We found no increase in bleeding (RR=0.80, 95% CI=0.5-1.4), death (RR=0.76, 95% CI=0.3-1.99) or "any adverse events" (RR=1.02, 95% CI=0.85-1.23) with device therapy. Sub-group analysis revealed that device closure significantly reduced the incidence of the composite primary endpoint among patients who had moderate to large shunt sizes (RR=0.22, 95% CI=0.02-0.42). CONCLUSIONS: Transcatheter closure is associated with a significant reduction in the risk of stroke compared to medical management at the expense of an increased risk of atrial arrhythmias.
Assuntos
Cateterismo Cardíaco/métodos , Procedimentos Cirúrgicos Cardíacos/métodos , Forame Oval Patente/cirurgia , Ensaios Clínicos Controlados Aleatórios como Assunto , Prevenção Secundária/métodos , Dispositivo para Oclusão Septal , Acidente Vascular Cerebral/prevenção & controle , Forame Oval Patente/complicações , Humanos , Acidente Vascular Cerebral/etiologia , Resultado do TratamentoRESUMO
BACKGROUND: The objective was to better understand Doppler hemodynamics and exercise capacity in patients with Fontan palliation by delineating the hemodynamic mechanism for temporal changes in their peak oxygen consumption (VÌo2). METHODS: We performed a retrospective review of adult Fontan patients with systemic left ventricle (LV) who underwent serial transthoracic echocardiograms (TTE) and cardiopulmonary exercise tests (CPET) at Mayo Clinic in 2000-2015. TTE and CPET data were used (1) to determine agreement between VÌo2 and Doppler-derived LV function indices (eg, stroke volume index [SVI] and cardiac index [CI]) and (2) to determine agreement between temporal changes in peak VÌo2 and LV function indices. RESULTS: Seventy-five patients (44 men; 59%) underwent 191 pairs of TTE and CPET. At baseline, mean age was 24±3 years, peak VÌo2 was 22.9±4.1 mL/kg/min (63±11 percent predicted), SVI was 43±15 mL/m2, and CI was 2.9±0.9 L/min/m2. Peak VÌo2 correlated with SVI (r=0.30, P<.001) and with CI (r=0.45, P<.001) in the 153 pairs of TTE and CPET in patients without cirrhosis. Temporal changes in percent predicted peak VÌo2 correlated with changes in SVI (r=0.48, P=.005) and CI (r=0.49, P=.004) among the 33 patients without interventions during the study. In the 19 patients with Fontan conversion, percent predicted peak VÌo2 and chronotropic index improved. CONCLUSIONS: Overall, there was a temporal decline in peak VÌo2 that correlated with decline in Doppler SVI. In the patients who had Fontan conversion operation, there was a temporal improvement in peak VÌo2 that correlated with improvement in chronotropic index.
Assuntos
Ecocardiografia Doppler/métodos , Teste de Esforço/métodos , Tolerância ao Exercício/fisiologia , Técnica de Fontan/métodos , Cardiopatias Congênitas/cirurgia , Centros Médicos Acadêmicos , Adulto , Fatores Etários , Estudos de Coortes , Dupla Via de Saída do Ventrículo Direito/diagnóstico por imagem , Dupla Via de Saída do Ventrículo Direito/cirurgia , Seguimentos , Cardiopatias Congênitas/diagnóstico por imagem , Humanos , Masculino , Michigan , Consumo de Oxigênio/fisiologia , Atresia Pulmonar/diagnóstico por imagem , Atresia Pulmonar/cirurgia , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Atresia Tricúspide/diagnóstico por imagem , Atresia Tricúspide/cirurgia , Adulto JovemRESUMO
BACKGROUND: To determine (1) correlation between Doppler stroke volume index (SVI) and cardiac magnetic resonance imaging (CMRI) SVI and (2) association between Doppler SVI and Fontan-associated diseases (FAD) and Fontan failure. METHODS: Review of Fontan patients who underwent same-day CMRI and transthoracic echocardiography (TTE), 2005 to 2015. We defined FAD as cardiac thrombus, protein-losing enteropathy, arrhythmia, and hospitalization for heart failure. Fontan failure was defined as Fontan conversion or revision, heart transplantation or listing, or death. RESULTS: Fifty-three patients with systemic left ventricle (LV) underwent 86 sets of TTE/CMRI. Mean (SD) age 31 (6) years. SVI (45 [16] vs 42 [13] mL/m2), CI (3.0 [1.1] vs 2.8 [0.8] L min-1 m-2), and ejection fraction (53 [4]% vs 51 [5]%) were similar for both modalities (P>.05 for all). Doppler SVI correlated with CMRI (r=0.68; P<.001). Sixteen patients had cirrhosis, and these patients had a higher CI (3.9 [0.9] vs 2.8 [1.0] L min-1 m-2; P<.01). Among the 37 patients without cirrhosis, Doppler SVI <39 mL/m2 was associated with FAD (odds ratio [OR], 2.11; 95% confidence limit, 1.26-3.14; P=.02); Fontan failure was more common in patients with CI was <2.5 L min-1 m-2 (3/9 [33%] vs 0/28 [0%], P=.01). Another 11 patients with systemic right ventricle (RV) underwent 17 sets of TTE/CMRI, mean (SD) age 17 (3) years, and CMRI SVI also correlated with Doppler SVI (r=0.75; P<.001). CONCLUSION: Doppler SVI correlated with CMRI SVI in patients with systemic LV and systemic RV. The association between output measures (SVI and CI) and FAD were seen only in single LV patients (single RV patients not assessed for this outcome due to small numbers). An association between low Doppler CI and Fontan failure was suggested in a small number of single LV patients.
Assuntos
Ecocardiografia Doppler/métodos , Técnica de Fontan , Cardiopatias Congênitas/diagnóstico , Ventrículos do Coração/diagnóstico por imagem , Volume Sistólico/fisiologia , Adulto , Feminino , Cardiopatias Congênitas/fisiopatologia , Ventrículos do Coração/fisiopatologia , Ventrículos do Coração/cirurgia , Humanos , Imagem Cinética por Ressonância Magnética , Masculino , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
There are limited studies of thrombotic and embolic complications (TEC) in the adult Fontan population. The purpose of the study was to determine the prevalence, risk factors, and outcomes of TECs in this population. METHODS: Retrospective review of adults with a previous Fontan operation, with follow-up at Mayo Clinic, 1994-2014. Systemic TEC was defined as intracardiac thrombus, ischemic stroke, or systemic arterial embolus. Nonsystemic TEC was defined as Fontan conduit/right atrial thrombus or pulmonary embolus. RESULTS: We identified 387 patients with a mean (SD) age of 28 (7) years and a mean follow-up of 8 (2) years. An atriopulmonary connection (APC) was done for 286 patients (74%). Atrial arrhythmias were present in 278 (72%). There were 121 TECs (systemic n=36, nonsystemic n=85) in 98 patients (25%). Risk factors for systemic TEC were atrial arrhythmia (hazard ratio 2.28, P=.001) and APC (hazard ratio 1.98, P=.02); nonsystemic TEC also had similar risk factors. All 98 patients received warfarin. Warfarin was discontinued in 10 of 98 because of bleeding, and 8 of these 10 subsequently had a second TEC. Among the 82 patients who had follow-up imaging, 16 (20%) had resolution of thrombus. In total, 24 of 98 patients had a second TEC, most of whom had inadequate anticoagulation. CONCLUSIONS: Thrombotic and embolic complication was not uncommon; risk factors for TEC were APC and atrial arrhythmias. Most patients were treated successfully with warfarin alone. A second TEC occurred in most patients whose anticoagulation was discontinued because of bleeding events.
Assuntos
Embolia/epidemiologia , Técnica de Fontan/efeitos adversos , Cardiopatias Congênitas/cirurgia , Complicações Pós-Operatórias/epidemiologia , Trombose/epidemiologia , Adolescente , Adulto , Arritmias Cardíacas/complicações , Embolia/etiologia , Feminino , Seguimentos , Átrios do Coração/cirurgia , Humanos , Estimativa de Kaplan-Meier , Masculino , Prevalência , Artéria Pulmonar/cirurgia , Fatores de Risco , Trombose/etiologiaRESUMO
BACKGROUND: Cardiac pacing can be challenging after a Fontan operation, and limited data exist regarding pacing in adult Fontan patients. The objectives of our study were to determine risk factors for pacing and occurrence of device-related complications (DRCs) and pacemaker reinterventions. METHODS: We performed a retrospective review of Fontan patients from 1994 through 2014. We defined DRCs as lead failure, lead recall, cardiac perforation, lead thrombus/vegetation, or device-related infection, and cardiovascular adverse events (CAEs) as venous thrombosis, stroke, death, or heart transplant. Pacemaker reintervention was defined as lead failure or recall. RESULTS: Of 439 patients, 166 (38%) had pacemakers implanted (79 during childhood; 87, adulthood); 114 patients (69%) received epicardial leads initially, and 52 (31%), endocardial leads. Pacing was initially atrial in 52 patients (31%); ventricular, 30 (18%); or dual chamber, 84 (51%). There were 37 reinterventions (1.9% per year) and 48 DRCs (2.4% per year). Pacemaker implantation during childhood was a risk factor for DRCs (hazard ratio, 2.01 [CI, 1.22-5.63]; P = .03). There were 70 CAEs (venous thrombosis, 5; stroke, 11; transplant, 8; and death, 46), yielding a rate of 3.5% per year. DRCs, CAEs, and reintervention rates were comparable for patients with epicardial or endocardial leads. CONCLUSIONS: More than one-third of adult Fontan patients referred to Mayo Clinic had pacemaker implantation. Epicardial leads were associated with high rate of pacemaker reinterventions but similar DRC rates in comparison to endocardial leads.
Assuntos
Estimulação Cardíaca Artificial/métodos , Técnica de Fontan , Cardiopatias Congênitas/cirurgia , Cuidados Pós-Operatórios/métodos , Complicações Pós-Operatórias/terapia , Adulto , Feminino , Seguimentos , Humanos , Incidência , Masculino , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Resultado do Tratamento , Estados Unidos/epidemiologia , Adulto JovemRESUMO
BACKGROUND: The optimal management strategy for atrial tachyarrhythmia in the Fontan population is unknown. METHODS: Retrospective review of 264 adult Fontan patients with atrial tachyarrhythmia evaluating 3 clinically adopted scenarios: antiarrhythmic drug (AAD) therapy, catheter ablation (CA), and Fontan conversion (FC). These patients were followed up at Mayo Clinic from 1994 to 2014. The study objective was to compare freedom from atrial tachyarrhythmia recurrence (AR) and occurrence of composite adverse events (stroke, heart failure hospitalization, death, or heart transplant) between treatment groups. RESULTS: The age of atrial tachyarrhythmia onset was 25 ± 4 years, time from Fontan operation was 13 ± 6 years, follow-up was 74 ± 18 months, atriopulmonary Fontan was 215 (81%), and atrial flutter/intra-atrial reentry tachycardia was 173 (65%). In those managed with AAD (n = 110), freedom from AR was 7% at 60 months. Catheter ablation (n = 31) was associated with an acute procedural success of 94%, and freedom from AR was 41% at 60 months. Fontan conversion (n = 33) resulted in a perioperative mortality of 3%, and freedom from AR was 51% at 60 months. Fontan conversion and CA were similar with regard to AR (P = .14) and significantly better compared with AAD (P < .0001). Adverse events were found to occur more frequently in the patients with AR (P < .0001) and the patients treated with AAD only (P < .0001). CONCLUSIONS: Catheter ablation and FC operations are associated with less recurrence of atrial tachyarrhythmia compared with AAD. Atrial tachyarrhythmias are more likely to recur in patients with a longer history of the arrhythmia and are associated with more adverse events. Early referral to a specialty center for these interventions should be considered.
Assuntos
Taquicardia/terapia , Adulto , Antiarrítmicos/uso terapêutico , Ablação por Cateter , Fenômenos Eletrofisiológicos , Feminino , Seguimentos , Técnica de Fontan , Átrios do Coração/fisiopatologia , Humanos , Masculino , Recidiva , Estudos Retrospectivos , Taquicardia/complicações , Taquicardia/fisiopatologia , Resultado do Tratamento , Adulto JovemRESUMO
OBJECTIVE: Despite the popularity of mindfulness in research and interventions, information is missing about how and why mindfulness may benefit employee sleep health. Drawing from emotion regulation theory, we evaluate affective rumination, negative affect, and positive affect as potential mechanisms. We also explore differential effects of trait and state attentional mindfulness on both subjective (e.g., quality and sufficiency) and actigraphy-measured aspects (e.g., duration and wake after sleep onset) of sleep health. METHOD: Ecological momentary assessment and sleep actigraphy data were collected across two independent samples of health care workers (N1 = 60, N2 = 84). Ecological momentary assessment was also used to collect daily information on state mindfulness, affect, and rumination. RESULTS: Our results support rumination and, to a less consistent extent, negative affect as mediators of the association between mindfulness and sleep health but not positive affect. Trait and state mindfulness demonstrate comparable benefits for employee sleep health, but these benefits largely emerge for subjective sleep dimensions than actigraphy-measured. CONCLUSIONS: These findings support emotion regulation as a sound theoretical framework for sleep and mindfulness research and may support more informed workplace mindfulness interventions. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
Assuntos
Actigrafia , Avaliação Momentânea Ecológica , Regulação Emocional , Atenção Plena , Humanos , Masculino , Feminino , Adulto , Regulação Emocional/fisiologia , Pessoa de Meia-Idade , Sono/fisiologia , Pessoal de Saúde/psicologia , Afeto/fisiologia , Ruminação Cognitiva/fisiologiaRESUMO
Aims: The spatiotemporal deep convolutional neural network (DCNN) helps reduce echocardiographic readers' erroneous 'judgement calls' on Takotsubo syndrome (TTS). The aim of this study was to improve the interpretability of the spatiotemporal DCNN to discover latent imaging features associated with causative TTS pathophysiology. Methods and results: We applied gradient-weighted class activation mapping analysis to visualize an established spatiotemporal DCNN based on the echocardiographic videos to differentiate TTS (150 patients) from anterior wall ST-segment elevation myocardial infarction (STEMI, 150 patients). Forty-eight human expert readers interpreted the same echocardiographic videos and prioritized the regions of interest on myocardium for the differentiation. Based on visualization results, we completed optical flow measurement, myocardial strain, and Doppler/tissue Doppler echocardiography studies to investigate regional myocardial temporal dynamics and diastology. While human readers' visualization predominantly focused on the apex of the heart in TTS patients, the DCNN temporal arm's saliency visualization was attentive on the base of the heart, particularly at the atrioventricular (AV) plane. Compared with STEMI patients, TTS patients consistently showed weaker peak longitudinal displacement (in pixels) in the basal inferoseptal (systolic: 2.15 ± 1.41 vs. 3.10 ± 1.66, P < 0.001; diastolic: 2.36 ± 1.71 vs. 2.97 ± 1.69, P = 0.004) and basal anterolateral (systolic: 2.70 ± 1.96 vs. 3.44 ± 2.13, P = 0.003; diastolic: 2.73 ± 1.70 vs. 3.45 ± 2.20, P = 0.002) segments, and worse longitudinal myocardial strain in the basal inferoseptal (-8.5 ± 3.8% vs. -9.9 ± 4.1%, P = 0.013) and basal anterolateral (-8.6 ± 4.2% vs. -10.4 ± 4.1%, P = 0.006) segments. Meanwhile, TTS patients showed worse diastolic mechanics than STEMI patients (E'/septal: 5.1 ± 1.2â cm/s vs. 6.3 ± 1.5â cm/s, P < 0.001; S'/septal: 5.8 ± 1.3â cm/s vs. 6.8 ± 1.4â cm/s, P < 0.001; E'/lateral: 6.0 ± 1.4â cm/s vs. 7.9 ± 1.6â cm/s, P < 0.001; S'/lateral: 6.3 ± 1.4â cm/s vs. 7.3 ± 1.5â cm/s, P < 0.001; E/E': 15.5 ± 5.6 vs. 12.5 ± 3.5, P < 0.001). Conclusion: The spatiotemporal DCNN saliency visualization helps identify the pattern of myocardial temporal dynamics and navigates the quantification of regional myocardial mechanics. Reduced AV plane displacement in TTS patients likely correlates with impaired diastolic mechanics.
RESUMO
In the current work, favipiravir (an antiviral drug) loaded pH-responsive polymeric hydrogels were developed by the free redical polymerization technique. Box-Behnken design method via Design Expert version 11 was employed to furnish the composition of all hydrogel formulations. Here, polyethylene glycol (PEG) has been utilized as a polymer, acrylic acid (AA) as a monomer, and potassium persulfate (KPS) and methylene-bisacrylamide (MBA) as initiator and cross-linker, respectively. All networks were evaluated for in-vitro drug release (%), sol-gel fraction (%), swelling studies (%), porosity (%), percentage entrapment efficiency, and chemical compatibilities. According to findings, the swelling was pH sensitive and was shown to be greatest at a pH of 6.8 (2500%). The optimum gel fraction offered was 97.8%. A sufficient porosity allows the hydrogel to load a substantial amount of favipiravir despite its hydrophobic behavior. Hydrogels exhibited maximum entrapment efficiency of favipiravir upto 98%. The in-vitro release studies of drug-formulated hydrogel revealed that the drug release from hydrogel was between 85 to 110% within 24 h. Drug-release kinetic results showed that the Korsmeyer Peppas model was followed by most of the developed formulations based on the R2 value. In conclusion, the hydrogel-based technology proved to be an excellent option for creating the sustained-release dosage form of the antiviral drug favipiravir.
Assuntos
Amidas , Antivirais , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Hidrogéis , Pirazinas , Preparações de Ação Retardada/química , Hidrogéis/química , Amidas/química , Amidas/administração & dosagem , Concentração de Íons de Hidrogênio , Antivirais/química , Antivirais/administração & dosagem , Antivirais/farmacocinética , Pirazinas/química , Pirazinas/administração & dosagem , Pirazinas/farmacocinética , Polietilenoglicóis/química , Reagentes de Ligações Cruzadas/químicaRESUMO
Symptomatic bradycardia may be iatrogenic or from a conduction system abnormality. Here we show an interesting case of iatrogenic symptomatic bradycardia that may be confused with a conduction system abnormality. (Level of Difficulty: Advanced.).
RESUMO
Nowadays, the use of statistical approaches, i.e., Box-Bhenken designs, are becoming very effective for developing and optimizing pharmaceutical drug formulations. In the current work, a Box-Bhenken design was employed using Design Expert version 11 to develop, evaluate, and optimize a hydrogel-based formulation for sustained release of an antiviral drug, i.e., favipiravir. The hydrogels were prepared using the free radical polymerization technique. ß-Cyclodextrin (ß-CD), N,N'-methylenebisacrylamide (MBA), acrylic acid (AA), and potassium per sulfate (KPS) were used as oligomer, crosslinker, monomer, and initiator, respectively. Three variables, including ß-CD (X1), MBA (X2), and AA (X3) were used at various concentrations for the preparation of hydrogels, followed by evaluation of a sol-gel fraction, swelling, porosity, chemical compatibilities, in vitro drug release, and entrapment efficiency. The results of the studies revealed that the degree of swelling was pH dependent, the best swelling being at pH 7.2 (1976%). On the other hand, for the low sol fraction of 0.2%, the reasonable porosity made the hydrogel capable of loading 99% favipiravir, despite its hydrophobic nature. The maximum entrapment efficiency (99%) was observed in optimized hydrogel formulation (F15). Similarly, in vitro drug release studies showed that the prepared hydrogels exhibited a good, sustained release effect till the 24th hour. The kinetic modelling of drug release data revealed that the Korsmeyer-Peppas model was best fit model, describing a diffusion type of drug release from the prepared hydrogels. Conclusively, the outcomes predict that the hydrogel-based system could be a good choice for developing a sustained-release, once-daily dosage form of favipiravir for improved patient compliance.
RESUMO
BACKGROUND: Aortic dilation and aortic valve disease are known long-term complication of tetralogy of Fallot (TOF), but the risk of aortic dissection and the indications for prophylactic aortic surgery are unknown in this population. The purpose of this study was to: (1) determine the prevalence of significant aortic valve disease and/or significant aortic aneurysm (AVD-AA); (2) determine the incidence of progressive aortic dilation and aortic dissection in patients with TOF. METHODS: Retrospective review of adults with repaired TOF, and no prior aortic valve/aorta surgery, who had ≥2 measurements of the thoracic aorta >12 months apart, 1990-2017. The aortic root and mid-ascending aorta were measured at the onset of QRS complex from leading edge to leading edge. Significant aortic valve disease was defined as the presence of ≥moderate aortic stenosis and/or ≥moderate aortic regurgitation. Significant aortic aneurysm was defined as aortic root or mid-ascending aorta dimension ≥50 mm. Progressive aortic dilation was defined as increase in aortic dimension ≥2 mm. RESULTS: Of the 453 consecutive patients (37±13 years, men 216 (49%)) in the study, aortic aneurysm was present in 312 (69%) based on normative data; progressive aortic dilation occurred in 40 (9%), and there was no case of aortic dissection. Significant AVD-AA occurred in 52 (12%) patients; and 15 of them (29%) underwent aortic surgery without any surgical mortality. CONCLUSIONS: Although aortic aneurysm was common, progressive aortic dilation was uncommon and aortic dissection did not occur in our patients with TOF with significant aortic aneurysms who did not undergo aortic surgery. This has important clinical implication in deciding the frequency of imaging follow-up and timing of surgical intervention in this population.
Assuntos
Aorta/diagnóstico por imagem , Aneurisma da Aorta Torácica/etiologia , Procedimentos Cirúrgicos Cardíacos/métodos , Tetralogia de Fallot/complicações , Procedimentos Cirúrgicos Vasculares/métodos , Adulto , Aneurisma da Aorta Torácica/epidemiologia , Aneurisma da Aorta Torácica/cirurgia , Ecocardiografia , Feminino , Seguimentos , Humanos , Incidência , Imagem Cinética por Ressonância Magnética/métodos , Masculino , Prevalência , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida/tendências , Tetralogia de Fallot/diagnóstico , Tetralogia de Fallot/cirurgia , Estados Unidos/epidemiologiaRESUMO
BACKGROUND: Elevation in central venous pressure (CVP) plays a fundamental pathophysiologic role in Fontan circulation. Because there is no sub-pulmonary ventricle in this system, CVP also provides the driving force for pulmonary blood flow. We hypothesized that this would make Fontan patients more susceptible to even low-level elevation in pulmonary vascular resistance index (PVRI), resulting in greater systemic venous congestion and adverse outcomes. METHODS: Adult Fontan patients and controls without congenital heart disease undergoing clinical evaluation that included cardiac catheterization and echocardiography were examined retrospectively. Outcomes including all-cause mortality and the development of Fontan associated diseases (FAD, defined as protein losing enteropathy, cirrhosis, heart failure hospitalization, arrhythmia, or thromboembolism) were assessed from longitudinal assessment. RESULTS: As compared to controls (nâ¯=â¯82), Fontan patients (nâ¯=â¯164) were younger (36 vs 45â¯years, pâ¯<â¯0.001), more likely to be on anticoagulation or antiplatelet therapy, and more likely to have atrial arrhythmia or cirrhosis. There was a strong correlation between CVP and PVRI in the Fontan group (râ¯=â¯0.79, pâ¯<â¯0.001), but there was no such relationship in controls. Elevated PVRI identified patients at increased risk for FAD (HR 1.92, 95% CI 1.39-2.41, pâ¯=â¯0.01), and composite endpoint of FAD and/or death (HR 1.89, 95% CI 1.32-2.53, pâ¯=â¯0.01) per 1â¯WU∗m2 increment. CONCLUSIONS: Systemic venous congestion, which is the primary factor in the pathogenesis of FAD and death, is related to even low-level abnormalities in pulmonary vascular function. Multicenter studies are needed to determine whether interventions targeting pulmonary vascular structure and function can improve outcomes in the Fontan population.
Assuntos
Pressão Venosa Central/fisiologia , Técnica de Fontan/tendências , Hiperemia/diagnóstico por imagem , Hiperemia/terapia , Circulação Pulmonar/fisiologia , Adulto , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Hiperemia/etiologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Resultado do TratamentoRESUMO
OBJECTIVES: The purpose of this study was to review the institutional practice of surveillance transthoracic echocardiography (TTE) for diagnosing early prosthetic valve dysfunction (PVD). BACKGROUND: Bioprosthetic valve thrombosis (BPVT) is an important cause of PVD, and guidelines do not recommend routine TTE during the first 5 years after valve implantation. METHODS: The authors performed a retrospective case-control study of all suspected (imaging diagnosis) or confirmed (histopathological diagnosis) cases of BPVT from January 1997 through December 2016. Patients were matched 1:2 (age, sex, prosthesis position) to patients whose prostheses were explanted because of structural failure (SF). PVD was defined as a 50% increase above baseline gradient at valve implantation and classified as early (≤5 years) or late (>5 years) after implantation. RESULTS: There were 94 BPVT (51 suspected, 43 confirmed) and 188 SF cases; patient age 61 ± 9 years; men 61 (65%). The prosthesis positions were aortic 56%; mitral 26%; tricuspid 15%; and pulmonary 3%. Early PVD was more common in the BPVT versus SF group: 83 of 94 (88%) versus 20 of 188 (11%) (p < 0.001). Time from implantation to PVD was shorter for BPVT than SF: 26 months (interquartile range [IQR]: 12 to 43 months) versus 74 months (IQR: 48 to 102 months) (p < 0.001). At the initial PVD diagnosis, 81% of BPVT and 90% of SF patients were asymptomatic. However, BPVT patients had rapid symptomatic deterioration, requiring intervention sooner after PVD diagnosis: 6 months (IQR: 4 to 7 months) versus 51 months (IQR: 22 to 55 months) (p < 0.001). CONCLUSIONS: Most patients with PVD due to BPVT were asymptomatic at initial diagnosis, which was made based on routine surveillance TTE, often performed before 5 years. BPVT, an acute disease process, requires timely diagnosis because patient conditions rapidly deteriorate. Further studies are needed to determine whether routine surveillance TTE should be considered for patients with bioprosthetic valves to identify pre-symptomatic features of BPVT in order to provide effective, appropriate therapy.
Assuntos
Bioprótese , Ecocardiografia , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/instrumentação , Próteses Valvulares Cardíacas , Valvas Cardíacas/cirurgia , Falha de Prótese , Trombose/diagnóstico por imagem , Idoso , Remoção de Dispositivo , Diagnóstico Precoce , Feminino , Valvas Cardíacas/diagnóstico por imagem , Valvas Cardíacas/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Desenho de Prótese , Estudos Retrospectivos , Trombose/etiologia , Trombose/fisiopatologia , Trombose/cirurgia , Fatores de TempoRESUMO
Aims: Determine the role of diastolic function indices in pre-operative and post-operative risk stratification in patients with moderate mixed aortic valve disease (MAVD). Methods and results: A retrospective study was conducted of asymptomatic patients with moderate MAVD (a combination of moderate aortic stenosis and moderate aortic regurgitation) and an ejection fraction of 50% or more who were followed up at Mayo Clinic from 1 January 2004, to 31 December 2013. A pre-requisite for inclusion in the study was assessment of diastolic function involving at least three of the following indices: tissue Doppler early diastolic velocity (e'), mitral inflow early velocity (E), tricuspid regurgitation velocity, and left atrial volume index. Primary endpoints were aortic valve replacement (AVR) or cardiac death while secondary endpoints were cardiovascular adverse events (CAEs) after AVR. We defined CAEs as stroke, heart failure hospitalization, severe left ventricular dysfunction, and cardiac death. There were 214 patients (age 61 ± 8 years, men 146 [68%]) followed for 6.1 ± 2.3 years during which 162 (76%) AVRs and 11 (5%) cardiac deaths occurred. The multivariable risk factors for cardiac death or AVR were relative wall thickness (RWT) > 0.42 [hazard ratio (HR), 1.88 [95% CI, 1.28-2.59]; P = 0.001] and average E/e' >14 (HR, 1.94 [95% CI, 1.29-3.01]; P = 0.02). Freedom from CAE after AVR was significantly lower in the patients with baseline RWT >0.42 or mean E/e' >14 than the other patients: 79% (95% CI 74-83%) vs. 94% (95% CI 89-98%) at 3 years (P = 0.03). Conclusion: The presence of RWT >0.42 or E/e' >14 identifies a high-risk patient subset whose risk for cardiovascular morbidities persists even after AVR.
Assuntos
Insuficiência da Valva Aórtica/epidemiologia , Estenose da Valva Aórtica/epidemiologia , Diástole/fisiologia , Ecocardiografia/métodos , Monitorização Fisiológica/métodos , Fatores Etários , Idoso , Análise de Variância , Insuficiência da Valva Aórtica/diagnóstico por imagem , Insuficiência da Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/cirurgia , Doenças Assintomáticas , Estudos de Coortes , Intervalos de Confiança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Medição de Risco , Fatores Sexuais , Volume Sistólico/fisiologia , Taxa de Sobrevida , Estados UnidosRESUMO
BACKGROUND: The relationship between temporal progression of magnetic resonance elastography derived liver stiffness (MRE-LS) and progression of Fontan associated liver disease (FALD) is unknown. To assess this relationship, we hypothesized that progression of MRE-LS correlated with progression FALD severity and clinical outcomes. METHODS: Retrospective review of Fontan patients who had >1 liver MRE, 2010-2016. Annual change in MRE-LS was the quotient of the difference between baseline and subsequent MRE-LS, and the interval between scans. RESULTS: 22 patients were enrolled; median age 29(19-38) years, 14 (64%) males and 10 (46%) with atriopulmonary Fontan. Baseline and subsequent MRE-LS values were 5.4⯱â¯1.1 kPa and 5.8⯱â¯0.9 kPa" for clarity, interval between scans was 25⯱â¯5â¯months, and annual change in MRE-LS was 0.3⯱â¯0.2â¯kPa. Temporal change in MRE-LS correlated with temporal changes in model for end-stage liver disease (MELD) score (râ¯=â¯0.84, pâ¯<â¯0.001) and model for end-stage liver disease excluding international normalized ratio (MELD-XI) score (râ¯=â¯0.75, pâ¯=â¯0.001). The study cohort was divided into 2 groups using the mean annual change in MRE-LS as the cut point. Groups A and B comprised of patients with annual increase in MRE-LS ≥0.3â¯kPa (nâ¯=â¯6) and <0.3â¯kPa (nâ¯=â¯16) respectively. Composite adverse event endpoint (death, heart-liver transplant listing, palliative care, hospitalization, paracentesis) was more common in Group A (4 of 6, 67%) compared to Group B (3 of 16, 19%), pâ¯=â¯0.13 although this did not reach statistical significance due to small sample size. CONCLUSIONS: Progression of MRE-LS correlated with clinical deterioration as measured by worsening liver disease severity scores and the occurrence of adverse events.