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Resumen Introducción: Las bioprótesis de válvulas cardiacas son el estándar de oro para el reemplazo quirúrgico de la válvula aórtica en pacientes seleccionados. Objetivo: Evaluar la seguridad y eficacia de la válvula cardiaca bioprotésica del Instituto Nacional de Cardiología (INC) en humanos. Métodos: Estudio unicéntrico que incluyó 341 pacientes que se sometieron a reemplazo valvular quirúrgico único de válvula aórtica con válvula INC. Resultados: Se realizaron 318 implantes de novo (93 %) y 23 como segunda cirugía (7 %); las puntuaciones STS fueron de 1.4 y 1.8 % y el seguimiento de 42 y 46 meses, respectivamente. No existieron diferencias en las complicaciones ni en la tasa de implantación de marcapasos. Ambos grupos mantuvieron una FEVI normal. Se observó mejoría global en la clase funcional con empeoramiento solo en dos pacientes del grupo de novo. La disfunción de la prótesis INC que ameritó reintervención quirúrgica se observó en ocho pacientes (4.65 %) del grupo de novo versus un paciente (7.69 %) con segunda cirugía. Conclusiones: La válvula cardiaca INC es eficaz y segura, se asocia a baja tasa de complicaciones y mejoría de la clase funcional durante el seguimiento a largo plazo. Se necesitan estudios prospectivos comparativos de esta válvula.
Abstract Introduction: Heart valve bioprostheses are the gold standard for aortic valve surgical replacement in selected patients. Objective: To evaluate the safety and efficacy of the of the National Institute of Cardiology (INC) bioprosthetic heart alve of the National Institute of Cardiology (INC) bioprosthetic heart valve in humans. Methods: Single-center study that ncluded 341 patients who underwent single surgical aortic valve replacement with INC heart valve. Results: 318 implants were performed de novo (93%) and 23 as redo surgery (7%); STS scores were 1.4 and 1.8%, and follow-up was for 42 and 46 months, respectively. There were no differences in clinical complications or pacemaker implantation rate. Both groups maintained a normal LVEF. Overall improvement in functional class was observed, with worsening only in two patients of the de novo group. INC prosthesis dysfunction requiring surgical reintervention was observed in eight patients (4.65%) of the de novo group vs. one patient in the redo group. Conclusions: The INC heart valve is efficacious and safe, and is associated with a The INC heart valve is efficacious and safe, and is associated with a low rate of complications and functional class improvement during long-term follow-up. Prospective, comparative studies of this valve are required.
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Worldwide, about 13% of the 200,000 annual recipients of prosthetic heart valves (PHV) present for various surgical procedures. Also, more and more females are opting for pregnancies after having PHV. All patients with PHV present unique challenges for the anesthesiologists, surgeons and obstetricians (in case of deliveries). They have to deal with the perioperative management of anticoagulation and a host of other issues involved. We reviewed the English language medical literature relevant to the different aspects of perioperative management of patients with PHV, particularly the guidelines of reputed societies that appeared in the last 20 years. Regression of cardiac pathophysiology following valve replacement is variable both in extent and timeline. The extent to which reverse remodeling occurs depends on the perioperative status of the heart. We discussed the perioperative assessment of patients with PHV, including focused history and relevant investigations with the inferences drawn. We examined the need for prophylaxis against infective endocarditis and management of anticoagulation in such patients in the perioperative period and the guidelines of reputed societies. We also reviewed the conduct of anesthesia, including general and regional anesthesia (neuraxial and peripheral nerve/plexus blocks) in such patients. Finally, we discussed the management of delivery in this group of high?risk patients. From the discussion of different aspects of perioperative management of patients with PHV, we hope to guide in formulating the comprehensive plan of management of safe anesthesia in such patients.
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Objective To study mechanical properties of polyethylene terephthalate (PET)-based textile valves woven with nickel-titanium (NiTi) wires by finite element method, and combined with in vitro hemodynamic testing, to analyze the effect of wire quantity and woven position on hemodynamic performance of PET textile valve. Methods The three-dimensional (3D) geometric models of PET valves without wires and models of PET valves with wires by different numbers and distributions in radial direction were constructed using modeling software. Material properties of PET valves and wires were given based on the literature and experimental data. The transvalvular pressure difference curves of PET valves obtained from in vitro pulsatile flow experiments were used as boundary conditions. Stress distributions of the valve during peak systole and diastole were studied by finite element analysis software. Hydrodynamic performance of the valve with wires was evaluated by in vitro pulsatile flow experiments. ResultsThe finite element analysis results showed that the radially woven NiTi wires could enhance support for the PET textile valve, and support force and area of the valve in belly region of the valve leaflet with evenly distributed metal wires increased with the number of metal wires. The situation of support force was similar for silk distributions on both sides of the belly. The weaving of wires reduced stress concentration on the PET textile valve to a certain extent. The pulsatile flow experiment results showed that the stability of opening and closing shapes, effective opening area (EOA), regurgitation fraction (RF) and transvalvular pressure differences for two kinds of the PET valves with woven wires were better than those of the PET valves without wires. Conclusions Weaving metal wires in radial direction of the PET textile valve can effectively reduce stress concentrations on the PET textile valve during the cardiac cycle, and reduce tearing possibility of the valve leaflet. The woven metal wires can improve opening and closing stability of PET textile valve in in vitro hydrodynamic test, increase EOA and reduce RF and transvalvular pressure difference of the PET valve.
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Background: The study aimed to evaluate the clinical presentation, diagnostic features, treatment strategies, and complications of prosthetic heart valve thrombosis (PHVT) and to determine efficacy, outcomes and complications of thrombolytic therapy during hospital stay.Methods: This was a prospective, observational, single-centre study carried out between March, 2016 and December, 2017 at a tertiary care centre in India. Total 110 patients with history of prosthetic heart valve replacement and symptoms related to PHVT were included in the study. Patients underwent thrombolysis, surgery or conservative management for treatment of PHVT, as per their individual clinical presentation. Clinical profile and treatment outcomes were assessed using a pre-tested, semi-structured questionnaire and clinical assessment.Results: Mean age of the patients was 39.4±12.5 years. Most of the patients presented with NYHA class II and III (85.4%) symptoms. Total 20.9% of patients were poorly compliant with anticoagulants. Thrombolysis was initial treatment in 105 (95.5%) patients. Five (4.6%) patients were treated with heparin. Two patients underwent surgery after failed thrombolysis. Mortality in the thrombolysis group was 6.6%. Embolism occurred in 8.6% of the group and major bleeding in 1.9%. One patient who underwent surgery died.Conclusions: In light of these results, it can be concluded that most cases of PHVT are due to inadequate anticoagulation and poor monitoring mainly in patients belonging to the lower socioeconomic group. Thrombolysis can be considered as first line therapy where the immediate surgical options are remote.
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Pregnancy after valve replacement for rheumatic heart disease is a high-risk pregnancy.There are risks of valve thrombosis,anticoagulation-related complications, prosthetic valve dysfunction and prosthetic valve endocarditis.Comprehensive preconception evaluation and strict management should be carried out in order to reduce maternal and neonatal complications.
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Objective To evaluate medium-term valvular functionality after transcatheter pulmonary valve replacement in sheep using a novel polymeric prosthetic pulmonary valve(PPHV). Methods In this study, we designed a novel polymeric trileaflet transcatheter pulmonary valve with a balloon-expandable stent, and the valve leaflet was made of 0. 1mm expanded polytetrafluoroethylene( ePTFE) . We chose bovine pericardium valve as control. Pulmonary valve stents were implanted in situ by right ventricular apical approach in 12 healthy sheep(10 for polymeric valve and 2 for bovine pericardium valve) weighing anaverageof(22.1±2.3)kg. Echocardiography,angiography,64-rowcomputedtomography(CT),andautopsywereusedto assess valvular function 12 weeks after implantation. Results Two PPHVs failed to be implanted in situ of pulmonary valve po-sition. Implantation was successful in the other 10 sheep. One sheep died of pneumonia, and the other 9 sheep survived at the end of follow-up. Echocardiography 12 weeks after implantation showed all the PPHVs exhibited good functionality and no sig-nificant insufficiency. The peak-peak transvalvular pressure gradient of the PPHVs was(28.2 ±8.0)mmHg(16-38 mmHg) (1 mmHg=0. 133 kPa), while that of two bovine pericardium valves were 16 and 21 mmHg. Angiography and CT 12 weeks after implantation demonstrated orthotopic position and normal operation of the valves,and no deformation of the valved stents. Pathological examination of the explanted PPHVs 12 weeks after implantation showed no degradation or damage of the ePTFE leaflets and most of the leaflets were thin and pliable, without significant thrombus or calcification, while visible pannus over-growth was found at the bottom of the valve leaflets, in the commissural areas and on the sealing cuff. Conclusion The medi-um-term effects of the novel ePTFE pulmonary valve after transcatheter pulmonary valve implantation in sheep is good. The no-vel PPHV exhibits good anti-adhesion, anti-degradation, anti-thrombus, anti-calcification performance and good biomechanical property. The hemodynamic parameter of PPHV is comparable to bovine pericardium valve. Optimizing the valve design might eliminate the problem about pannus overgrowth.
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Objective To explore the values and relationship among the contents of thrombus precursor protein(TpP)and plasma D-dimer(D-D),complications after mechanical heart valve replace-ment and their correlation with international normalized ratio(INR)in anticoagulation therapy and monito-ring.Methods A total of 150 patients with mechanical heart valve replacement were enrolled.TpP,D-D, INR,other indicators and complications were compared to draw conclusions.Results There were signifi-cant differences in TpP among the groups(P<0.0083).Significant differences in D-D among the postop-erative group(100.96 ±61.56),thrombosis group(17.78 ±5.94)and control group(5.97 ±1.58)were observed(P<0.0083).Significant differences in INR among the postoperative group(1.65 ±0.34),hem-orrhage group(2.22 ±0.65)and control group(1.11 ±0.10)were observed(P<0.0083),but the effec-tiveness of INR monitoring for determining the state of thrombosis was limited to a certain extent.Conclu-sion TpP and D-D examination can facilitate monitoring after mechanical heart valve replacement,and it has a certain guiding significance for determining anticoagulation therapy and monitoring of complications after mechanical heart valve replacement.
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Objective To evaluate valvular functionality after transcatheter pulmonary valve replacement in sheep using a novel polymeric prosthetic pulmonary valve.Methods In this study,we designed a novel polymeric trileaflet transcatheter pulmonary valve with a balloon-expandable stent,and the valve leaflet was made of 0.1 mm expanded polytetrafluoroethylene (ePTFE).We chose bovine pericardium valve as control.Pulmonary valve stents were implanted in situ by right ventricular apical approach in 8 healthy sheep(6 for polymeric valve and 2 for bovine pericardium valve) weighing an average of(22.8 ± 2.2) kg.Angiography was performed after implantation to assess immediate valvular function.Color Doppler echocardiography and 64-row computed tomography were used to assess valvular function 4 weeks after implantation.Results Implantation was successful in 8 sheep.Angiography at implantation showed one polymeric valve was located below the ideal position and most of the stent was in the outflow tract of right ventricle.While,all the other prosthetic valves demonstrated orthotopic position and exhibited normal open and close functionality.Echocardiography 4 weeks after implantation showed all the prosthetic valves exhibited normal functionality and no significant insufficiency.The peak-peak transvalvular pressure gradient of the polymeric valves was (18.8 ± 6.0) mmHg,while that of two bovine pericardium valves were 9 mmHg and 20 mmHg.CT 4 weeks after implantation demonstrated orthotopic position of the stents except the above-mentioned one and all the stents had no deformation.Conclusion The success rate of transcatheter pulmonary valve replacement by right ventricular apical approach is satisfactory.The early valvular functionality of the novel ePTFE pulmonary valve after transcatheter pulmonary valve replacement in sheep is good.
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Due to development of new prosthetic heart valves(PHV) and advanced operative technology, the result of prosthetic valve replacement has improved, but problems such as thromboembolism, bleeding, structural valve deterioration, and patient-prosthesis mismatch are not yet resolved. The aging society, different life style and sensual change for life affected the type of operation and life quality after the operation. During four decades, the mechanical valve has been designed for less or no structural valve deterioration and manufacturers have mixed high-tech for prevention of thrombosis. However, the necessity of anticoagulation therapy is still remained. And the durability of the tissue valve has also been increased by development in technology of tissue preservation and fixation. But the risk of thromboembolism and structural failure is not completely resolved and it is far from perfect for replacing the mechanical valve. The long-term result of homograft is disappointing. However, the result of the pulmonary autograft is hopeful, except that it needs a very complex operation and therefore, it is limited to an experienced surgeon. Recent study shows that patient's characteristics are important to determine the long-term results and durability of the prosthetic valve. It needs to be reemphasized that, for better results of PHV replacement, we consider the patient's characteristics and types of PHV and discuss the options with our patients.
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Humanos , Envejecimiento , Aloinjertos , Autoinjertos , Válvulas Cardíacas , Corazón , Hemorragia , Esperanza , Estilo de Vida , Calidad de Vida , Tromboembolia , Trombosis , Conservación de TejidoRESUMEN
Due to development of new prosthetic heart valves(PHV) and advanced operative technology, the result of prosthetic valve replacement has improved, but problems such as thromboembolism, bleeding, structural valve deterioration, and patient-prosthesis mismatch are not yet resolved. The aging society, different life style and sensual change for life affected the type of operation and life quality after the operation. During four decades, the mechanical valve has been designed for less or no structural valve deterioration and manufacturers have mixed high-tech for prevention of thrombosis. However, the necessity of anticoagulation therapy is still remained. And the durability of the tissue valve has also been increased by development in technology of tissue preservation and fixation. But the risk of thromboembolism and structural failure is not completely resolved and it is far from perfect for replacing the mechanical valve. The long-term result of homograft is disappointing. However, the result of the pulmonary autograft is hopeful, except that it needs a very complex operation and therefore, it is limited to an experienced surgeon. Recent study shows that patient's characteristics are important to determine the long-term results and durability of the prosthetic valve. It needs to be reemphasized that, for better results of PHV replacement, we consider the patient's characteristics and types of PHV and discuss the options with our patients.
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Humanos , Envejecimiento , Aloinjertos , Autoinjertos , Válvulas Cardíacas , Corazón , Hemorragia , Esperanza , Estilo de Vida , Calidad de Vida , Tromboembolia , Trombosis , Conservación de TejidoRESUMEN
The spectral analysis of heart valve sound is a noninvasive diagnostic method known to be useful in evaluating the state of the heart valve function. This may provide early detection of valve calcification, thrombus or destruction, since previous studies have shown that the dominant frequency peak moved to a high frequency area when natural heart valve leaflets were calcified, stiffened or destroyed. However, it is important for a heart valve sound diagnostic system to find a proper spectral analysis method on phonocardiography. Until now, conventional frequency analyses such as the Fourier transform or autoregressive spectral estimation technique have been used to estimate spectral components of a phonocardiogram, but they are inappropriate because the signal frequency is assumed to remain constant during the transform interval. To overcome this problem, in this study, FOS (Fast Orthogonal Search) & MUSIC (MUltiple SIgnal Classification), which both appeared suitable for the analysis of biological data, were applied to prosthetic heart valve sound as the new heart valve sound spectral analysis methods. Five subjects with normally functioning mechanical heart valves and a patient with a malfunctioning one were selected to collect the heart valve sound signals. As a result, the second dominant peak frequency proved to be important along with the first dominant peak frequency in identifying the valve function. This study showed that the new heart valve sound spectral analysis method presented in this paper may be an effective method in heart valve sound analysis. Further study using this system in a large population of patients will aid in providing a diagnostic method in the early detection of valve failure.
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Femenino , Humanos , Masculino , Ruidos Cardíacos , Enfermedades de las Válvulas Cardíacas/diagnóstico , Implantación de Prótesis de Válvulas Cardíacas , Procesamiento de Señales Asistido por ComputadorRESUMEN
An hemodynamic evaluation of two mechanical heart valves is presented. A tilting disc valve and a bileaflet valve were incorporated in a mock circulatory system which consists of a closed flow loop with a pneumatically driven flexible diaphragm to simulate the physiologic pulsatile flow. Comparisons between the valves were made on the aortic pressure, ventricular pressure, as well as mean pressure gradient at a systolic duration of 45% and a heart rate of 90 beats per minute. The results showed that the tilting disc valve has higher ventricular pressure and mean pressure gradient than that of the bileaflet valve. This indicates that the tilting disc valve has higher transvalvular flow resistance and energy loss than that of the bileaflet valve. From this study it is demonstrated that the mock circulatory system can be a very useful device to evaluate the prosthetic heart valves in vitro.