Modified chordal sparing mitral valve replacement as effective technique for both stenotic and insufficient mitral valves.

BACKGROUND: Chordal apparatus preservation is important for preserving left ventricular (LV) function in the long-term perspective. We present results of originally modified chordal-sparing mitral valve replacement (MVR) successfully used in patients with mitral stenosis and mitral insufficiency. METHODS: The modified surgical method involves preserving only four strut chords with portions of the mitral valve leaflets, which are later fixed to the fibrous ring. The rest of the leaflets and marginal chords are removed. RESULTS: Starting from 1998, 484 modified universal chordal-sparing MVR were performed including 270 (55.79%) in patients with rheumatic mitral stenosis and 214 (44.21%) in patients with mitral valve insufficiency. Overall, 116 patients underwent isolated MVR, and 368 patients underwent MRV with concomitant surgical procedures. The overall in-hospital mortality was 2.5% (12 patients). Long-term efficiency was assessed in patients discharged after isolated MVR (114 patients), average follow-up period was 3.1±0.6 years. Preservation of strut chords ensured normalization of intraventricular anatomy and prevented LV dilatation; the LV Sphericity Index is maintained at 0.44-0.63. Heart failure functional class (NYHA) was improved in all patients. Non-fatal prosthesis-related complications were observed in 11 patients (9.65%). Three patients (2.63%) died due to extracardiac causes. CONCLUSIONS: The proposed modification of the strut chordal-sparing mitral valve replacement technique allows preserving functionally complete annulo-papillary apparatus, regardless of the nature of valvular dysfunction, and provides parallel movement to the mechanical prosthesis. This modified surgical technique is safe and effective and eliminates the risk of jamming of the prosthesis disk and left ventricular outflow tract obstruction.

Low mutation rate in the TTN gene in paediatric patients with dilated cardiomyopathy - a pilot study.

Idiopathic dilated cardiomyopathy (DCM) is a common cardiomyopathy with the prevalence of 1:250, and at least one-third of all the cases are inherited. Mutations in the TTN gene are considered as the most frequent cause of inherited DCM and cover 10-30% of the cases. The studies were mainly focused on the adult or mixed age group of patients with DCM. The mutation rate in the TTN gene, the characteristics of manifestations and their prognostic significance in childhood have not been studied. To determine TTN mutation rate in children with DCM and the relevance of including this gene in the DNA diagnostic protocol for paediatric DCM, complete clinical and instrumental examination of 36 DCM patients (up to 18 years) with the manifestation of the disease was conducted in specialised cardiology centres. Molecular genetic testing included sequencing of coding and adjacent regulatory regions of the major cardiac TTN isoform N2BA using IonTorrent ™ semiconductor sequencing (for 25 isolated cases) and trio whole exome sequencing (trio WES)on the Illumina platform (for 11 family cases). Our pilot group included 36 probands with DCM diagnosis first established on the basis of the generally accepted criteria at the age of 5 days to 18 years(average age: 6.5 years). The sex ratio (M:F) was 23: 8. There were 25 sporadic DCM cases and 11 cases of familial DCM (at least one of the parents and/or siblings were also diagnosed with DCM). The only likely pathogenic truncating variant p.Arg33703*in the TTN gene (TTNtv) was found in a 16-year-oldmale proband out of 36 (3%). Apparently, TTN-dependent forms of DCMs manifest later at a young (but older than 18 years) or more mature age, and TTN gene cannot be considered as the first-line genetic testing for DCM in the paediatric group, despite several studies have reported a generally high mutation rate in this gene with DCM. Further research is needed to compare the representation of mutations in the TTN gene in different age groups of DCM patients.