Medium long-term follow-up outcomes of BalMedic® bovine pericardial bioprosthetic valve in the mitral position

Background

In China, where Rheumatic heart disease is still prevalent, two thirds of valve replacements are in mitral position. Before a valve replacement operation is conducted, most patients have reached Class III/IV heart function under the New York Heart Association (NYHA) classification system. As the background to this disease is quite different to that of degenerated cases, which are more prevalent in Western countries, the development of an artificial heart valve that is suitable for local patients is very significant for China. In this medium long-term clinical follow-up study, a data analysis was conducted of domestic heart valve production for mitral replacement.

Methods

A total of 288 patients who underwent mitral valve replacements from 2005 to 2015 at 2 cardiac surgery centres (i.e., The Affiliated Hospital of Qingdao University, and The First People’s Hospital of Yulin) were evaluated. All implanted bioprostheses were BalMedic^® bovine pericardial bioprosthetic valves, which had been granted marketing approval by the China Food and Drug Administration (CFDA) in 2003. Double valve cases that involved both aortic and mitral replacements were not included in the study. On average, patients were aged 54.5±10.8 (range, 11 to 77 years) before the procedure. The mean follow-up period was 7.2±2.6 years. The study examined the overall survival (OS) curve, and different age group results. To gain further insights into the functions of the valves, the OS curve and the age group results for the reoperation-free and structural valve deterioration (SVD)-free rates are also presented.

Results

The 10-year OS rate was 65.6%, the 10-year reoperation-free rate was 76.3%, and the 10-year SVD-free rate was 58.0%. In relation to the age group results, younger patients had higher survival rates, while older patients had higher reoperation-free rates and SVD-free rates.

Conclusions

In relation to the medium long-term clinical follow-up results, the durability performance of the BalMedic^® bovine pericardial valve in the mitral position was satisfactory, especially among patients whose heart function was worse than that of Western sufferers. Survival rate, reoperation-free rate and SVD-free rate were used for the comprehensive analysis.

Microbiota in Gut, Oral Cavity, and Mitral Valves Are Associated With Rheumatic Heart Disease

Rheumatic heart disease refers to the long-term damage of heart valves and results from an autoimmune response to group A Streptococcus infection. This study aimed to analyze the microbiota composition of patients with rheumatic heart disease and explore potential function of microbiota in this disease. First, we revealed significant alterations of microbiota in feces, subgingival plaques, and saliva of the patients compared to control subjects using 16S rRNA gene sequencing. Significantly different microbial diversity was observed in all three types of samples between the patients and control subjects. In the gut, the patients possessed higher levels of genera including Bifidobacterium and Eubacterium, and lower levels of genera including Lachnospira, Bacteroides, and Faecalibacterium. Coprococcus was identified as a super-generalist in fecal samples of the patients. Significant alterations were also observed in microbiota of subgingival plaques and saliva of the patients compared to control subjects. Second, we analyzed microbiota in mitral valves of the patients and identified microbes that could potentially transmit from the gut or oral cavity to heart valves, including Streptococcus. Third, we further analyzed the data using random forest model and demonstrated that microbiota in the gut, subgingival plaque or saliva could distinguish the patients from control subjects. Finally, we identified gut/oral microbes that significantly correlated with clinical indices of rheumatic heart disease. In conclusion, patients with rheumatic heart disease manifested important alterations in microbiota that might distinguish the patients from control subjects and correlated with severity of this disease.