Surgical treatment of chronic atrial fibrillation combined with rheumatic mitral valve disease: Effects of the cryo-maze procedure and predictors for late recurrence.
OBJECTIVE
The aim of this study was to evaluate the effects of the modified maze procedure using cryoablation for treating chronic atrial fibrillation (AF) associated with rheumatic mitral valve disease and to assess the risk factors for late failure of sinus rhythm restoration.


METHODS
Between March 2000 and June 2004, 170 consecutive patients, who underwent the modified maze procedure using cryoablation concomitant with mitral valve surgery for atrial fibrillation associated with rheumatic mitral valve disease, were divided into two groups based on the type of right-sided maze: the modified Cox-maze III (CM group, n=93) and modified Kosakai-maze (KM group, n = 77) procedures. The postoperative and mid-term follow-up results were analyzed and compared between the two groups. Both univariate and multivariate analyses were used to assess the risk factors for late recurrence of atrial fibrillation.


RESULTS
There were three in-hospital deaths, including two in the CM group (2.2%) and one in the KM group (1.3%), and there were no significant differences in the incidence of postoperative complications between the two groups. The cardiopulmonary bypass and aortic cross-clamp times were significantly shorter in the KM group than the CM group. At discharge, the sinus rhythm rate was 70% in the CM group and 74% in the KM group (p = 0.55). Follow-up was completed in 97% of the patients, with a mean time of 26.6+/-15.2 months. At the latest follow-up, one death occurred in the CM group (0.6%). Sinus rhythm was documented in 141 (84%) out of all the patients, including 76 (84%) in the CM group and 65 (86%) in the KM group (p=0.72). The 4-year actuarial survival free from stroke was 90.3+/-5.9% for the CM group and 96.4+/-3.5% for the KM group (p = 0.68), and 4-year event-free survival was 81.2+/-7.4% for the CM group and 96.4+/-3.5% for the KM group (p = 0.078). Using a multivariate analysis, a left atrial dimension >65 mm (p = 0.011) and repair for rheumatic mitral valve disease (p = 0.038) were independent risk factors for a late recurrence of AF.


CONCLUSIONS
The modified maze procedures using cryoablation are safe and effective in treating chronic atrial fibrillation associated with rheumatic mitral valve disease.
Baek
Man-Jong
MJ
Department of Thoracic and Cardiovascular Surgery, College of Medicine, Korea University, Seoul, Republic of Korea. mdmjbaek@korea.ac.kr
Na
Chan-Young
CY
Oh
Sam-Se
SS
Lee
Chang-Ha
CH
Kim
Jae Hyun
JH
Seo
Hong Joo
HJ
Park
Sang-Won
SW
Kim
Wook Sung
WS
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology / Q000601:surgery*; D002908:Chronic Disease; D003452:Cryosurgery / Q000379:methods*; D004812:Epidemiologic Methods; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000150:complications / Q000601:surgery*; D008946:Mitral Valve Stenosis / Q000150:complications / Q000601:surgery*; D011183:Postoperative Complications; D011379:Prognosis; D012008:Recurrence; D012214:Rheumatic Heart Disease / Q000150:complications / Q000601:surgery*; D020521:Stroke / Q000209:etiology; D016896:Treatment Outcome