Objective To explore the role of thrombus precursor protein(TPP) in the monitoring of anticoagulation in the patients with atrial fibrillation (Af) after mechanical heart valve replacement, and suggest the reasonable anticoagulant range. Methods Ninety patients were divided into Af group (n=45), sinus rhythm group (SR group, n=45), and control group (20 patients with non-valvular heart diseases), according to whether Af exist after mitral valve replacement. TPP concentrations and International Normalized Ratio(INR) in the anticoagulant patients were analyzed. Results In patients after mechanical mitral valve replacement, plasma TPP concentrations in both SR group and Af group were lower than that in control group (Plt;0.05,0.01), their INR value were higher than that in control group (Plt;0.01), and Af group had higher plasma TPP concentrations than that in SR group((Plt;)0.05). It was found that there existed contradictions between INR and plasma TPP concentrations in Af group. There were 28 patients with plasma TPP concentrations below 6 μg/ml and without spontaneous bleeding complications in the group with Af, who might be at the optimal anticoagulant status. Their 95% confidence of INR value was 1.90-2.30 and their plasma TPP concentration was 4.29±0.75μg/ml. Conclusion Patients with Af after mechanical heart valve replacement might have higher risk of thromboembolism, INR between 1.90 - 2.30 and plasma TPP concentration between 2.84-6.00 μg/ml might be the optimal anticoagulant therapeutic range.
Based on the analysis of the influence of the valve pivot distance on the performance of mechanical heart valve (MHV), such as the valve opening and closing features, flow field characteristics and the valve assembly properties, value constraints of the valve pivot distance were established, and the reasonable valve was obtained by means of the finite element method. It can be shown that the central flow characteristics of the valve could be enhanced with the increasing of the ratio of pivot distance to valve inner diameter, but the plastic deformation of the ring could be liable to occur in the MHV assembly process. It is proved that the valve of specifications can be designed in similar ratio of pivot distance to valve inner diameter according to the result of the valve performance experiment.
The pulsatile flow experiment can not only evaluate the preclinical safety and risk of prosthetic heart valve (PHV) but also play an important role in the computational model and fluid simulation, providing an experimental basis for the performance optimization of PHV. This paper mainly reviews the development and the latest progress of PHV pulsatile flow experiments and the characteristics of experimental pulse duplicator, and discuss the research direction of pulsatile flow experiments, expecting a further development in this field.
ObjectiveTo study the biocompatibility of bioprosthetic heart valve material with a non-glutaraldehyde-based treatment, and to provide the safety data for the clinical application. MethodsAll the tests were conducted according to GB/T16886 standards. The in vitro cytotoxicity was determined by methyl thiazolyl tetrazolium assay. Fifteen guinea pigs were divided into a test group (n=10) and a control group (n=5) in the skin sensitization test. Three New Zealand white rabbits were used in the intradermal reactivity test. Five sites on both sides of the rabbit back were set as test sites and control sites, respectively. In the acute systemic toxicity test, a total of 20 ICR mice were randomly assigned to 4 groups: a test group (polar medium), a control group (polar medium), a test group (non-polar medium) and a control group (non-polar medium), 5 in each group. Forty SD rats were divided into a test group (n=20) and a control group (n=20) in the subchronic systemic toxicity test. ResultsThe viability of the 100% extracts of the bioprosthetic heart valve material with a non-glutaraldehyde-based treatment was 75.2%. The rate of positive reaction was 0.0%. The total intradermal reactivity test score was 0. There was no statistical difference in the body weight between the test group and control group in the acute systemic toxicity test. There was no statistical difference in the body weight, organ weight, organ weight/body weight ratio, blood routine test or blood biochemistry between the test group and control group in the subchronic systemic toxicity test. ConclusionThe bioprosthetic heart valve material with a non-glutaraldehyde-based treatment has satisfying biocompatibility, which conforms to relevant national standards. The material might be a promising material for application in valve replacement.
ObjectiveTo describe the status of quality of life (QOL) and self-management behavior in patients following mechanical heart valve replacement, and explore the relationship between QOL and self-management behavior.
MethodsConvenient sampling was used to recruit 352 patients following mechanical heart valve replacement in a high-level hospital in Chengdu between January 2011 and June 2012. General information questionnaire, MOS SF-36 scales, and self-management behavior questionnaire were used to collect data. T-test was used to analyze the difference between patients and normal people. And correlation analysis was used to see the correlation between QOL and self-management.
ResultsFor MOS SF-36 scale results in patients within one year after surgery, physical functioning (PF) score was 73.44±15.11, role-physical (RP) was 49.52±39.17, body pain (BP) was 63.13±17.93, general health (GH) was 58.85±14.88, vitality (VT) was 63.54±18.10, social functioning (SF) was 76.67±17.40, role-emotional (RE) was 64.96±41.37, and mental health (MH) was 72.76±17.40. All these scores of the patients were significantly lower than the norm of Sichuan Province (P<0.05) except the dimension of mental health. For patients one year or more after surgery, PF score was 76.53±14.41, RP 58.44±39.21, BP 68.16±18.26, GH 61.39±13.57, VT 68.47±16.37, SF 79.79±19.34, RE 72.94±37.29, and MH 75.87±14.70, among which PF, RE, BP and GH scores were lower than the norm (P<0.05). The average total score of self-management behavior was 143.21±20.63. QOL and self-management behavior were positively correlated.
ConclusionThere is still a gap between patients following mechanical heart valve replacement and normal people in terms of quality of life. Patients' self-management behavior is positively correlated with the quality of life. Good self-management behavior contributes to the improvement of QOL.
Objective To observe whether Cyclo-RGDfK (Arg-Gly-Asp-D-Phe-Lys) could enhance the adhesion of myofibroblast to decellularized scaffolds and upregulate the expression of Integrin αVβ3 gene. Methods Myofibroblast from the rat thoracic aorta was acquired by primary cell culture. The expression of Vimentin and α-smooth muscle actin(α-SMA) has been detected by immunoflurescent labeling. Decellularized valves have been randomly divided into three groups (each n=7). Group A (blank control): valves do not receive any pretreatment; Group B: valves reacted with linking agent NEthylN(3dimethylaminopropyl)carbodiimide hydrochloride (EDC) for 36 hours before being seeded; Experimental group: Cyclo-RGD peptide has been covalently immobilized onto the surface of scaffolds by linking agent EDC. The fifth generation of myofibroblast has been planted on the scaffolds of each group. The adhesion of myofibroblast to the scaffolds was evaluated by HE staining and electron scanning microscope. The expression of Integrin αVβ3 was quantified by halfquantitative reverse transcriptionpolymerase china reaction (RT-PCR). Results We can see that myofibroblast has exhibited b positive staining for Vimentin and α-SMA. Besides, it has been shown that the expression of Integrin αVβ3 was much higher in the experimental group than that of the group A and group B(Plt;0.05). There was no statistically difference in group A and group B (P=0.900). Conclusion RGD pretreatment does enhance the adhesive efficiency of seeding cells to the scaffolds and this effect may be related to the upregulation of Integrin αVβ3.
ObjectiveTo systematically review therapy-related complications incidences of warfarin with different anticoagulation intensity in Chinese after mechanical heart valve replacement, and to explore the suitable anticoagulation intensity of warfarin.
MethodsWe electronically searched The Cochrane Library (Issue 2, 2013), EMbase, PubMed, CNKI, CBM, WanFang Data and VIP for studies about therapy-related complications rates of warfarin with different anticoagulation intensity in Chinese after mechanical heart valve replacement from inception to March 2013. Two reviewers independently screened literature according to inclusion and exclusion criteria, extracted data, and assessed methodological quality of included studies. Then meta-analysis was performed using RevMan 5.2.
ResultsA total of 7 studies involving 3 787 cases were finally included, 2 985 cases in Group A (targeted INR≤2.3) and 802 cases in Group B (targeted INR > 2.3). The results of meta-analysis showed that, compared with Group B, the total therapy-related complications incidence of warfarin with different anticoagulation intensity significantly decreased in Group A (OR=0.35, 95%CI 0.28 to 0.44, P < 0.000 01). The incidence of hemorrhage in Group A (OR=0.15, 95%CI 0.08 to 0.27, P < 0.000 01) was lower than that in Group B. However, the incidence of embolism in Group A was higher than that in Group B (OR=2.77, 95%CI 1.54 to 4.98, P=0.000 7).
ConclusionApplying low-intensity anticoagulation for Chinese patients after mechanical heart valve replacement could reduce the overall incidences of anticoagulation-related complications and hemorrhage, but it could also significantly increase the incidence of thrombosis.
Objective To introduce a new type of bileaflet mechanical prosthetic heart valve （GK bileaflet valve）and evaluate clinically the early hemodynamic effect and short term follow-up after its replacement. Methods Sixty-one patients with heart valve diseases were operated upon. The mitral valve replacement was performed in 34 patients, aortic valve replacement in 16 patients and double valve replacement in 11 patients. A total of 72 GK bileaflet mechanical valves were implanted, 45 in mitral position, and 27 in aortic position. Blood consistency and hemodynamics were monitored. Follow-up was carried out routinely to check whether there were some valve-related complications. Results There was no early mortality （〈30 d）. Only one patient died of trauma 2 months after the operation. Follow-up was 100% and extended 1 to 2. 5 years. Without valve-related complications all patients had lived for more than 1 to 2.5 years. In 98% （60/61） of survivors heart functional performance had improved to New York Heart Association class Ⅰ or Ⅱ . Conclusion Early clinical results and short term follow up demonstrate that GK bileaflet prosthetic heart valve exhibits excellent hemodynamic properties, satisfied blood consistency and a low incidence of valve-related complications. Midterm and long-term results should be observed further.
ObjectiveTo explore the effect of pulmonary hypertension on the clinical efficacy of Cox Maze Ⅳ procedure in treating atrial fibrillation (AF) patients with valvular heart disease.MethodsThe clinical data of 84 patients who received cardiac valve replacement and Cox Maze Ⅳ ablation in our hospital from July 2017 to January 2020 were retrospectively analyzed. According to the estimation of pulmonary artery pressure (PAP) by ultrasound, the patients were divided into two groups: a group A (PAP<45 mm Hg, 20 males, 26 females with an average age of 59.1±7.8 years) and a group B (PAP≥45 mm Hg, 15 males and 23 females with an average age of 58.5±8.5 years). The PAP was less than 70 mm Hgin all patients. A systematic follow-up review was performed for 6 months after operation. The recovery and recurrence rate of sinus rhythm after surgical ablation were compared between the two groups, and the efficacy was analyzed.Results(1) All the patients completed the operation successfully, and there was no statistical difference in the ablation time between the two groups (P>0.05); no patients died of pulmonary infection after the operation, and one patient underwent implantation of a permanent pacemaker due to conduction block. (2) At the end of the operation and 3 months after the operation, the conversion rate of AF in the group A was 91.3% (42 patients) and 82.6% (38 patients), respectively, and in the group B was 89.5% (34 patients) and 73.7% (28 patients), respectively (P>0.05). The conversion rate of AF was 82.6% (38 patients) in the group A and 63.2% (24 patients) in the group B at 6 months after operation (P=0.043). Binary logistic regression analysis showed that PAP≥45 mm Hg had a significant effect on the long-term effect of surgical Maze procedure in treating AF patients with valvular heart disease [P=0.014, OR=5.661, 95%CI (1.429, 22.432)].ConclusionPAP may be an influencing factor for the long-term effect of surgical Maze procedure in treating AF patients with valvular heart disease. Although the long-term recurrence rate of AF in the moderate pulmonary hypertension group is higher than that in the group A, the overall effect is still safe and effective; therefore it is still worth promoting in clinical application.
Transcatheter aortic valve replacement has revolutionized the management of aortic stenosis and become the gold standard for the treatment of symptomatic and severe aortic valve stenosis in elderly patients. With the improvement in design and materials, newer generation transcatheter aortic valve prostheses had overcome the limitations of early-generation devices that were susceptible to paravalvular leak, atrioventricular block and vascular complications, to a certain extent. This review provides an update on the latest advances in transcatheter aortic valve prostheses.
