[Long-term outcome of transcatheter repair of paravalvular leak post surgical mitral valve replacement].

Objective: To explore the long-term clinical efficacy of transcatheter repair of mitral paravalvular leak (PVL) post surgical mitral valve replacement. Methods: This study is a retrospective study. Patients who completed transcatheter repair of paravalvular leak after surgical mitral valve replacement at Shanghai Chest Hospital, Shanghai Jiaotong University School of Medicine from March 2010 to December 2018 were included. Technical success was defined as the occluder being stably implanted in the paravalvular leak site without affecting the function of the mitral valve and surrounding tissues; and there were no intervention-related complications, such as new hemolysis or aggravated hemolysis, and echocardiography confirmed mitral paravalvular regurgitation reduced by more than 1 grade. Patients were followed up at 30 days, 1, and 3 years after the intervention. The main endpoints were all-cause death and re-surgery due to interventional failure or serious complications. The occurrence of occluder-mediated hemolysis and chronic renal insufficiency was recorded, and patients were monitored with echocardiography during follow up. Results: A total of 75 patients were included, aged (54.3±22.9) years old, and 38 patients were males. All patients had decreased cardiac function and/or hemolysis before intervention. Procedural success was achieved in 54 patients (72.0%). Incidence of device-mediated hemolysis was 18.7% (14/75). During the follow-up period, all-cause death occurred in 7 patients (9.3%), and 3 were cardiac deaths.The 3-year event-free survival rate was 81.3% (61/75). The need for cardiac surgery was 9.3% (7/75): 3 cases due to severe device-mediated hemolysis, 2 cases due to prosthetic valve failure and 2 cases due to moderate to severe residual regurgitation. The echocardiography follow-up results showed that the position of the occluder was stable, there was no impact on the artificial valve function and surrounding structures, and the residual regurgitation was stable without progressive increase in event-free patients. Compared with pre-intervention, the left ventricular end systolic diameter ((33.9±7.4)mm vs. (38.3±8.9) mm, P=0.036), end diastolic diameter ((53.7±8.3) mm vs. (58.4±9.1) mm, P=0.045) and left atrial diameter (59.3 (44.5, 90.7) mm vs. 64.3 (44.8, 96.6) mm, P=0.049) were significantly reduced, pulmonary artery systolic pressure was also significantly decreased ((36.5±15.8) mmHg vs. (46.3±14.9) mmHg, P=0.022, 1 mmHg=0.133 kPa). There was no significant difference between 3 years and 1 year after transcatheter repair of mitral paravalvular leak post surgical mitral valve replacement (all P>0.05). Conclusion: Transcatheter repair of mitral paravalvular leak post surgical mitral valve replacement is an effective treatment option in selective patients.

A novel single nucleotide polymorphism in exon 7 of LPL gene and its association with carcass traits and visceral fat deposition in yak (Bos grunniens) steers.

Lipoprotein lipase (LPL) is considered as a key enzyme in the lipid deposition and metabolism in tissues. It is assumed to be a major candidate gene for genetic markers in lipid deposition. Therefore, the polymorphisms of the LPL gene and associations with carcass traits and viscera fat content were examined in 398 individuals from five yak (Bos grunniens) breeds using PCR-SSCP analysis and DNA sequencing. A novel nucleotide polymorphism (SNP)-C→T (nt19913) was identified located in exon 7 in the coding region of the LPL gene, which replacement was responsible for a Phe-to-Ser substitution at amino acid. Two alleles (A and B) and three genotypes designed as AA, AB and BB were detected in the PCR products. The frequencies of allele A were 0.7928, 0.7421, 0.7357, 0.6900 and 0.7083 for Tianzhu white yak (WY), Gannan yak (GY), Qinghai-Plateau yak (PY), Xinjiang yak (XY) and Datong yak (DY), respectively. The SNP loci was in Hardy-Weinberg equilibrium in five yak populations (P>0.05). Polymorphism of LPL gene was shown to be associated with carcass traits and lipid deposition. Least squares analysis revealed that there was a significant effect on live-weight (LW) (P<0.01), average daily weight gain (ADG) and carcass weight (P<0.05). Individuals with genotype BB had lower mean values than those with genotype AA and AB for loin eye area and viscera fat weight (% of LW) in 25-36 months (P<0.05). The results indicated that LPL gene is a strong candidate gene that affects carcass traits and fat deposition in yak.