Anticoagulation and antiplatelet therapy in patients with prosthetic heart valves

Establishment of prediction algorithm for the Honghe minority group based on warfarin maintenance dose

Background: CYP2C9 and VKORC1 are important factors in warfarin metabolism. The authors explored the effects of these genetic polymorphisms and clinical factors on a warfarin maintenance dose and then established the prediction algorithm for Honghe minorities in China. Materials & methods: Quantitative fluorescence PCR determined the mutation frequency of CYP2C9 and VKORC1-1639 G>A alleles. The authors collected the relevant clinical factors, including age, gender, body surface area (BSA), international normalized ratio value, daily warfarin dose, comorbidity and concomitant prescriptions. Results: The mean values of BSA and international normalized ratio in Honghe minorities were lower than in Han Chinese (p = 0.00). The genotype of CYP2C9*1/*1 and VKORC1-1639 AA was the main allele, the mutationfrequency of VKORC1-1639 AA and the number of male of Honghe minorities were lower than that of Han Chinese (p = 0.013 and p = 0.04). The significances of the effect on actual warfarin dose value were gender, VKORC1 AA mutant, CYP2C9*1/*1, age, hypertension and BSA sequentially. Conclusion: By multiple linear regression analysis with genetic and clinical factors, the authors determined a prediction algorithm for adjusting individual dosing of warfarin in this population. Clinical trial registration number: ChiCTR2100051778.

Natural Polymers in Heart Valve Tissue Engineering: Strategies, Advances and Challenges

In the history of biomedicine and biomedical devices, heart valve manufacturing techniques have undergone a spectacular evolution. However, important limitations in the development and use of these devices are known and heart valve tissue engineering has proven to be the solution to the problems faced by mechanical and prosthetic valves. The new generation of heart valves developed by tissue engineering has the ability to repair, reshape and regenerate cardiac tissue. Achieving a sustainable and functional tissue-engineered heart valve (TEHV) requires deep understanding of the complex interactions that occur among valve cells, the extracellular matrix (ECM) and the mechanical environment. Starting from this idea, the review presents a comprehensive overview related not only to the structural components of the heart valve, such as cells sources, potential materials and scaffolds fabrication, but also to the advances in the development of heart valve replacements. The focus of the review is on the recent achievements concerning the utilization of natural polymers (polysaccharides and proteins) in TEHV; thus, their extensive presentation is provided. In addition, the technological progresses in heart valve tissue engineering (HVTE) are shown, with several inherent challenges and limitations. The available strategies to design, validate and remodel heart valves are discussed in depth by a comparative analysis of in vitro, in vivo (pre-clinical models) and in situ (clinical translation) tissue engineering studies.

Self-care training and informational support of patients with a mechanical heart valve on the international normalized ratio and bleeding complications

AIM

The aim of the study was to determine the effect of self-care training and informational support of patients with a mechanical heart valve on the international normalized ratio (INR) and bleeding complications.

MATERIAL AND METHODS

Design: A quasi-experimental study. Participants were recruited via convenience sampling and were randomly divided into two groups: control (n = 80) and intervention (n = 80). Participants in the control group received only routine training; in addition, the intervention group received 6 sessions of self-care training and 6 months of informational support. Monthly the level of INR and incidence of bleeding were determined. Data were analyzed using the independent t-test and χ2 in SPSS16 software at a significance level of 0.05.

RESULTS

During 6 months of follow-up, except for the third month, the frequency of INR levels in the therapeutic target range (2.5-3.5) in the intervention group was significantly higher than that in the control group (p < 0.05). Also in the intervention group, the incidence of bleeding complications was lower than that in the control group, but this difference was not statistically significant (p > 0.05).

CONCLUSIONS

Proper self-care training and informational support in patients with mechanical heart valve replacement have positive results. By maintaining self-care, the level of a therapeutic target range of INR can be maintained and the incidence of bleeding complications can be reduced.