J Korean Med Sci.  2010 Oct;25(10):1467-1472. 10.3346/jkms.2010.25.10.1467.

Alternative Energy Sources for Surgical Treatment of Atrial Fibrillation in Patients Undergoing Mitral Valve Surgery: Microwave Ablation vs Cryoablation

• Kim JB
• Cho WC
• Jung SH
• Chung CH
• Choo SJ
• Lee JW

• KMID: 2157851
• DOI: http://doi.org/10.3346/jkms.2010.25.10.1467

Abstract

The study aim was to compare maze outcomes using microwave ablation or cryoablation in patients with mitral disease and atrial fibrillation (AF). Between 1999 and 2005, 340 patients underwent mitral valve surgery and concomitant maze procedure involving either microwave ablation (n=96, MW group) or cryoablation (n=244, Cryo group). Mean age at operation was 50.0+/-12.5 yr. Follow-up period was 46.1+/-28.2 months. The Cryo group showed a longer aortic clamping time than the MW group (P=0.005). There were no differences in operative mortality and morbidity rates. The unadjusted 5-yr AF free rate was 61.3+/-1.2% in the MW group and 79.9+/-3.2% in the Cryo group (P=0.089). After adjustment, the MW group only showed a tendency toward more frequent AF recurrence than the Cryo group (Hazard ration 1.66, 95% confidence interval 0.89 to 3.07). Multivariate analysis revealed that older patient age (P<0.001) and greater left atrial size (P<0.001) were independent risk factors for AF recurrence. Although the use of microwave ablation results in shorter aortic clamping time, it has a tendency toward more frequent late AF recurrence than with cryoablation.

Keyword

Atrial Fibrillation; Mitral Valve; Ablation Therapy; Surgery

MeSH Terms

Adult
Aged
Atrial Fibrillation/mortality/*surgery/therapy
*Cryosurgery
Disease-Free Survival
Female
Follow-Up Studies
Humans
Male
*Microwaves
Middle Aged
Mitral Valve/*surgery

Figure

• 

  Fig. 1 Freedom from AF without administration of antiarrhythmic agents. In the Cryo group, the AF-free rates were 87.8%±2.2% at 3 yr and 79.9%±3.2% at 5 yr. In the MW group, the AF-free rates were 79.9%±4.9% at 3 yr and 61.3%±1.2% at 5 yr (P=0.089). AF, atrial fibrillation.

• 

  Fig. 2 Transmitral A-wave prevalence (%). Inter-group comparisons of A-wave prevalence show no differences during the postoperative period (P values ranged from 0.18 to 1.0 for each postoperative point).

• 

  Fig. 3 Transmitral peak A-wave velocity (cm/sec). Inter-group comparisons of A-wave velocity show no differences during the postoperative period (P values ranged from 0.16 to 0.84 for each postoperative point).

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