The Correlations Between Circulating Levels Of Myocardial Collagen Metabolism Markers And The Pattern Of Atrial Fibrillation

Objective Electrical remodeling and structural remodeling has relation to the occurrence and maintenance mechanism of atrial fibrillation. Atrial structural remodeling to promote excitement for anisotropic conduction, making the coupling between the heterogeneity of myocardial cells to increase, shortening the wavelength of the non-directional block is conducive to the formation of reentrant mechanisms, thus contributing to the occurrence and maintenance of atrial fibrillation. Myocardial fibrosis is the main performance of atrial structural remodeling,and the pathologic entity of extracellular matrix remodeling. Collagen is the principal structural protein, and collagen types I and III are the most abundant in the ECM. MMP-1 and TIMP-1 are coexpressed in cardiac fibroblasts and are regulated to maintain the architecture of the ECM,once the balance of synthesis and degradation of ECM damage, resulting in myocardial fibrosis. To investigeted the correlation between circulating levels of myocardial collagen degradation or synthesis markers and the pattern of atrial fibrillation,by detecting serum myocardial collagen metabolism markers and MMP-1, TIMP-1 in Pe-Af group, Pa-Af group and SR group.Methods Serum C-terminal propeptide of collagen type-I (CICP), C-terminal propep- tide of procollagen type I (PICP) ,N-terminal propeptide of procollagen type I (PINP), N-terminal type III collagen peptide(PIIINP), matrix metalloproteinase-1, and tissue inhibitor of matrix metalloproteinases-1 were measured as markers of collagen synthesis and degradation by enzyme-linked immunoadsorbent assay, and C-terminal telopeptide of collagen type-I (ICTP) was assayed using Electrochemiluminescence,in 49 patients with Pe-Af,40 patients with Pa-Af,and 30 healthy control subjects in sinus rhythm.Results CICP, PICP and PIIINP were significantly higher in atrial fibrillation patients than in sinus rhythm study group (P<0.01),and Pe-Af group was higher than Pa-Af group (P <0.01),but no differences were found in PINP levels between atrial fibrillation and sinus rhythm study groups(P=0.054). Atrial fibrillation group had significantly higher levels of TIMP-1 and ICTP(P <0.01) compared with sinus rhythm group.Pe-Af group had lower levels of MMP-1(P <0.01),but higher levels TIMP-1 (P<0.01), when compared with Pa-Af group, and levels of ICTP tended to be higher (P=0.128). In all Af patients taken together, there was a positive correlation between CICP,PICP,PIIINP, and TIMP levels and LA dimension,and the correlation coefficient r were 0.636 ,0.776,0.932,and 0.620 respectively. While there was a weak,inverse correlation between CICP,PICP,PIIINP,and TIMP levels and LVEF,and the correlation coefficient r were -0.530 ,-0.568,-0.459,and -0.499 respectively.Conclusions Serum markers of myocardial collagen metabolism markers differed significantly between persistent atrial fibrillation and paroxysmal atrial fibrillation. Myocardial fibrosis is involved in the presence and maintenance of mechanisms of atrial fibrillation. MMP-1 activation in a time-dependent,which expression increased in the paroxysmal atrial fibrillation group.But no differences were found in MMP-1 levels between atrial fibrillation and sinus rhythm study groups. There was a positive correlation between CICP,PICP,PIIINP, and TIMP levels and LA dimension.While there was a weak,inverse correlation between CICP,PICP,PIIINP,and TIMP-1 levels and LVEF. The LA dimension larger,LVEF lower ,the more obvious of atrial fibrosis.