Cardiac Rhythm and Atrial Transport Function After Surgical Ablation of Atrial Fibrillation Using Cryoenergy: Predictors and Effectiveness of the Procedure

Abstract

Aim. The aim of this prospective study was to assess the presence of sinus rhythm and atrial transport function after surgical ablation of atrial fibrillation using cryoenergy, and to evaluate predictors of the success of the procedure.Methods. Between January 2005 and September 2006, 100 consecutive patients underwent left atrial cryoablation as a concomitant surgical procedure (46 patients with paroxysmal or persistent atrial fibrillation and 54 with permanent atrial fibrillation). Mitral valve surgery was performed in 74%. The mean and the median times of follow-up were 20 ± 8.5, and 24 months respectively. Atrial mechanical function was assessed by echocardiography.Results. Sinus rhythm was achieved during the postoperative follow-up in 71-81% of patients -significantly more often in the group with paroxysmal and persistent atrial fibrillation (90-98%), than patients with permanent atrial fibrillation prior to surgery (51-65%) (p<0.002). At 12 and 24 months after the surgery, a total of 68.2% and 51.2% of the patients were free from atrial fibrillation; 73.9% and 60.7% of the patients from the paroxysmal and persistent atrial fibrillation group, and 60.3% and 37.7% of patients with permanent atrial fibrillation (p=0.05). Five per cent of patients required postoperative permanent pacemaker implantation. An effective left and right atrial mechanical function was detected in 70-90%, and 96-98% of patients with sinus rhythm respectively. The following circumstances were identified as negative predictors of the presence of sinus rhythm after the ablation procedure: growing diameter of the left atrium, the duration of atrial fibrillation and the severity of mitral and tricuspid regurgitation before surgery (p<0.05). Restoration of the left atrial transport function was negatively predicted by the preoperative diameter of the left atrium, the presence of mitral valve stenosis and the severity of tricuspid regurgitation (p<0.05). A total of 95.4% of patients were free from stroke at one-year follow-up, and 94.1% at 2 years after surgery.Conclusion. Stable sinus rhythm and effective left atrial transport function are the main factors resulting in decreased morbidity after successful ablation of atrial fibrillation. A careful post-operative follow-up of the patients and individualised treatment are necessary.

Assessment of the effect of left atrial cryoablation enhanced by ganglionated plexi ablation in the treatment of atrial fibrillation in patients undergoing open heart surgery

“…In our present, as well as previous study [ 58 ], we managed to achieve similar good outcomes with performance of left atrium ablation in achievement and duration of NSR in the group of patients with paroxysmal and persistent AF. However, in the group of patients with long-standing persistent, or permanent AF, we observed a significantly higher AF recurrence, which increases with the period of follow-up.…”

“…2.2% at the end of one-year follow-up. In the previous study [ 58 ] performed at our centre, the incidence of thromboembolic events was 4.6%, or 5.9%, at the end of one-year and two-year follow-up, respectively. This corresponds with the frequency of thromboembolic events in patients after surgical ablation presented in published studies and results summarized in the meta-analysis by Gray et al from 2011 [ 74 ].…”

How effective is cryoablation for atrial fibrillation during concomitant cardiac surgery?

“…At five-year follow-up it was shown that those who had undergone cryoablation had a higher (although non-significant) rate of SR conversion compared with the microwave group (79.9% vs. 61.3%, P=0.089). Given that aortic cross-clamp time was longer in the cryoablative group and the fact that there were no significant Kolek and Brat [8] and Mack et al [9] reviewed the results of left atrial cryoablation. In agreement with Gammie et al [7], Kolek and Brat showed a high rate of SR conversion in those suffering paroxysmal but not permanent AF after 12-month follow-up (89.7 vs. 61.9%, P=0.005).…”

“…All nine papers were either small randomised controlled trials or retrospective studies with small sample sizes (57-521) and varied follow-up regimens. Six of nine studies [2,[4][5][6][7][8] suggested that cryoablation is most successful in patients suffering from paroxysmal rather than permanent AF. A lack of 24-hour monitoring in seven of nine studies [2-6, 9, 10] prevents effective elucidation of the rate of paroxysmal AF following cryoablation.…”

Cardiac surgery interventions for stroke prevention in patients with atrial fibrillation

“…Rovněž platí, že obnova SR ne vždy znamená obnovu mechanické (transportní) funkce síní. Podle literárních údajů je účinná transportní funkce levé síně obnovena u 60-90 % a účinné kontrakce pravé síně u 80-100 % pacientů s úspěšně obnoveným SR [52]. Prav-děpodobnost obnovy transportní funkce levé síně roste spolu s dobou uplynulou od zákroku; proto období pooperačního "omráčení" síně i pacienti, u nichž k obnově transportní funkce nedojde vůbec, představují jedince spojené s vyšším tromboembolickým rizikem i v přítomnosti SR. Zde pomáhá před případným vysazením antikoagulace echokardiografi cké vyšetření, které je cílené na transportní funkci síní.…”