Abstract 16204: Transforming Growth Factor beta1 mRNA Expression in Left Atrium and Recovery of Atrial Contraction After Surgical Maze Procedure
Background: The maze procedure for atrial fibrillation (AF) is effective in restoring sinus rhythm. However, significant proportion of patients failed to recover atrial mechanical contraction (AMC). We hypothesized that preoperative level of atrial transforming growth factor-β1 (TGF-β1) mRNA expression would be related to recovery of AMC.
Methods and Results: Preoperative atrial TGF-β1 mRNA was measured in 128 consecutive patients who underwent the mitral valve surgery combined with maze procedure with cryoablation for persistent AF. Presence of AMC was assessed using Doppler echocardiographic measurement of the transmitral A-wave velocity. At one year follow-up, patients without AMC (n=62) had higher levels of atrial TGF-β1 mRNA expression and more extensive atrial fibrosis than those with AMC (n=66): median TGF-β1/GAPDH mRNA with interquartile range, 0.42 (0.22-0.57) versus 0.28 (0.16-0.42), P=0.01. When the patients were divided into 3 groups according to the TGF-β1 mRNA level, the recovery rate of AMC and the increment of A-wave velocity gradually decreased from the lowest to the highest group. Multiple logistic regression analysis revealed that TGF-β1 mRNA levels were independently associated with the postoperative absence of AMC at 1 year's follow-up (odd ratio 7.47, 95% CI 1.63-34.4, P=0.01). In a subgroup analysis, it was also identified as an independent parameter for the development of atrial mechanoelectrial dissociation, a state of no AMC even in restored sinus rhythm (P=0.01).
Conclusions: Atrial TGF-β1 mRNA expression was significantly associated with no recovery of atrial mechanical activity or with the development of atrial mechanoelectrical dissociation one year after the surgical maze procedure using cryoablation.
- © 2011 by American Heart Association, Inc.