Impact of volume reduction in giant left atrium during surgical ablation of atrial fibrillation

Abstract

Background: An enlarged left atrium (LA) is a well-known risk factor for ablation failure of atrial fibrillation (AF). We analyzed the result of concomitant AF ablation in patients with a giant LA and evaluated the effect of LA volume reduction.Methods: Between 2000 and 2011, 116 patients with a giant LA (antero-posterior dimension ≥70 mm) who underwent surgical AF ablation during MV surgery were retrospectively reviewed. Among these, 28 patients received aggressive LA volume reduction procedure (reduction group) while the other 88 patients received the surgery without LA volume reduction (non-reduction group). Mean follow-up duration was 6.8±3.0 years.Results: Aortic clamping and cardio-pulmonary bypass times were significantly longer in reduction group than non-reduction group (P<0.001 and 0.025, respectively). There were no significant differences in early mortality rates (3.7% vs. 5.7%, P>0.99) and major complication rates. Rates of freedom from AF at 1, 3 and 5 years were 84.2%, 74.3% and 54.5%, respectively in reduction group and 49.0%, 33.2% and 28.4%, respectively in non-reduction group (P=0.013). Multivariable analysis revealed severe pulmonary hypertension as an independent risk factor for AF recurrence (HR, 15.9; 95% CI, 1.69-149.54, P=0.015) while LA volume reduction (HR, 0.50; 95% CI, 0.28-0.89, P=0.018) and the use of cryoablation instead of radiofrequency (HR, 0.11; 95% CI, 0.01-0.95, P=0.045) were found to be protective against AF recurrence.Conclusions: Aggressive LA volume reduction was found to improve rhythm outcomes in patients with a giant LA undergoing surgical AF ablation.

A new surgical technique for left atrial reduction in giant left atrium

“…The principal indication for LA reduction surgery is the presence of compressive symptoms or a history of thromboembolic events. 8 , 15 , 17 , 21 , 24 , 25 As expected, most of our participants had this medical history at the preoperative stage, but we observed a significant reduction of these symptoms after surgery. Likewise, these results are linked to the substantial improvement in NYHA functional class observed during the follow-up, which is directly correlated to the patients' quality of life and mortality risk.…”

“…Certain authors argue that AF, a mortality predictor in patients with GLA, could be another indication for LA reduction surgery. 22 , 24 The dilatation of the LA is one of the predictors of the modified Maze procedure; in a cohort of patients undergoing operation for AF, Kawaguchi and colleagues 26 demonstrated that those remaining in AF (vs patients with restored SR) had a significantly higher incidence of GLA and larger cardiothoracic ratio and LA dimension; most patients with postoperative LA size less than 40 mm or cardiothoracic ratio less than 55% had restored SR. Kim and colleagues 25 found that LA volume reduction and cryoablation instead of radiofrequency were protective against AF recurrence during surgical ablation of AF. Kasemsarn and colleagues 27 reported that reducing the LA diameter to less than 50 mm increases the success of conversion to SR in patients undergoing radiofrequency ablation.…”

“…Other authors have supported this hypothesis. 25 , 26 , 27 , 28 Nevertheless, in the absence of empirical evidence, future studies are required.…”

Decreased diastolic hydraulic forces incrementally associate with survival beyond conventional measures of diastolic dysfunction

“…LA reduction surgery is already an established procedure (30)(31)(32)(33)(34) primarily indicated alongside other surgical procedures to treat an enlarged LA or chronic atrial fibrillation in patients with mitral valve disease (31). Several studies have highlighted the benefits of LA reduction surgery in these circumstances, most commonly resulting in increased restoration and maintenance of sinus rhythm, with no significant increases in mortality or post-operative complications (35)(36)(37)(38)(39)(40)(41). The exact mechanism for these improvements is not clearly understood.…”

Perioperative management of patients with prosthetic heart valves-A narrative review

“…[ 16 ] MVR combined with LA volume reduction with cryoablation led to high rates of sustained relief from AF with incidences of 84.2%, 74.3% and 54.5%, at 1, 3 and 5 years respectively, compared to 49.0%, 33.2% and 28.4%, respectively in non-reduction group ( P = 0.013). [ 17 ]…”