Materials and methods: 47 pts (m:f 18:29) undergoing septal myectomy for HCM and 30 healthy pts as control group were included. ECHO, contrast enhancement cardiac MRI, histology specimens (obtained at septal myectomy) analysis, circulating fibrosis biomarkers (TGFß1, MMP-2,9, TIMP-1, galectin-3, sST2, CITP, PICP, PIIINP, NT-proBNP) were performed. Pts with HCM were examined before surgery, as well as 7 days, 6 and 12 months after surgery.
Results: The mean value of maximum LVOT gradient was 88 (55; 192) mm Hg, maximum wall thickness - 22±3 mm in pts with HCM. The extent of late gadolinium interventricular septum enhancement ranged from 32 to 53%. Square of myocardial fibrosis by histological data was ? 13.9±6.9%. Increased serum PICP, PIIINP, galectin-3, sST2, TGFß1 levels were revealed in pts with HCM in comparison with the controls. Increased CITP level was associated with myocardial fibrosis by histological assay (r=0.356; p=0.028) and TIMP-1 level was related with wall thickness (r=0.502; p<0.001). Nevertheless, level MMP-9 was increased. Male pts had a higher level of TIMP-1 (p = 0.004), level of sST2 (p = 0.0008) and risk of SCD (?=0.028) in compare with female pts. Pts with severe myocardial fibrosis had a negative prognosis of left atrium size reduction.
Conclusion: Circulating fibrosis markers can be used for risk stratification in pts with HCM. Myocardial fibrosis is mainly determined factor in the long-term outcome in pts with HCM after septal myectomy.