title: The role of matrix metalloproteinase-2 in the treatment of atrial fibrillation recurrence after a radiofrequency modified maze procedure.
abstract: OBJECTIVE
  Our study aimed to elucidate the potential clinical and molecular issues in recurrent atrial fibrillation (AF) following a radiofrequency modified maze procedure in patients with rheumatic valvular disease and persistent AF.
  
  
  RESULTS
  Eighty patients with rheumatic valvular disease and persistent AF (lasting more than 6 months) who had undergone a radiofrequency modified maze procedure and mitral valve replacement were enrolled into this single-center pilot study and were followed up for another 6 months. Their clinical characteristics were analyzed and the expression of matrix metalloproteinase (MMP)-2 including its specific inhibitor and collagen volume fraction (CVF) was also assessed. During the 6-month follow-up, 24 subjects had recurrent AF. Among them, the left atrial diameter was larger compared to that achieved in sinus rhythm (SR). The mRNA and protein expression of MMP-2 was significantly increased in recurrent AF patients, while its specific inhibitor did not show a significant difference (p > 0.05). The CVF of type I collagen increased significantly in the recurrent AF patients compared to SR patients (18.16 ± 3.22 vs. 11.66 ± 3.38, p < 0.001), whereas the CVF of type III collagen showed no significant difference (8.33 ± 3.44 vs. 9.55 ± 3.67, p > 0.05).
  
  
  CONCLUSIONS
  This study suggests that the overexpression of MMP-2 is associated with CVF-I in the left atrial appendage which potentially leads to the recurrence of AF following a radiofrequency modified maze procedure in patients with rheumatic valve disease.
authors.affiliation: Department of Cardiovascular Surgery, Cardiovascular Institute and Fuwai Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.forename: Sheng-Shou
authors.initials: SS
authors.lastname: Hu
authors.forename: Yun-Hu
authors.initials: YH
authors.lastname: Song
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D020517:Atrial Appendage; D001281:Atrial Fibrillation / Q000150:complications / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D024042:Collagen Type I / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D008875:Middle Aged; D008946:Mitral Valve Stenosis / Q000150:complications; D010865:Pilot Projects; D012008:Recurrence; D012214:Rheumatic Heart Disease / Q000150:complications
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III; D020778:Matrix Metalloproteinase 2