Which Method to Use for Surgical Ablation of Atrial Fibrillation Performed Concomitantly with Mitral Valve Surgery: Radiofrequency Ablation versus Cryoablation

Abstract

ObjectiveThe effects of energy source on the maintenance of sinus rhythm and the contribution of demographic characteristics to the case selection in patients submitted to ablation performed concurrently with mitral valve surgery were analyzed.MethodsCryothermal (n=42; 43.8%) and radiofrequency (n=54; 56.3%) energy were employed in 96 patients submitted to mitral valve replacement and Cox maze IV procedure. Patients were called for control visits between 15 days and 12 months after discharge. The causal relationship between recurrence of atrial fibrillation and factors such as left atrial diameter, C-reactive protein, hypertension, left ventricular ejection fraction, chronic obstructive pulmonary disease, and body mass index was determined.ResultsMaintenance rates of the sinus rhythm with radiofrequency and cryoablation were 97.6% and 96.3%, respectively, in the first postoperative month, whereas at the 12th postoperative month were 88.1% and 83.3%. No significant difference was found between groups in relation to the energy source. Sensitivity and specificity for left atrial diameter with a cut-off value of 50.5 mm were 85.7% and 70.7%, respectively. Sensitivity and specificity for C-reactive protein with a cut-off value of 12 mg/dL on the 15th postoperative day were 83.3% and 88.9%, respectively. The effect of body mass index on atrial fibrillation recurrence was 3.2 times. Sensitivity and specificity for left ventricular ejection fraction 37% cut-off value were 96.3% and 11.4%, respectively. Atrial fibrillation in hypertensive cases was 5.3 times more. In patients with chronic obstructive pulmonary disease, recurrence of atrial fibrillation was 40%. The causal relation between recurrence of atrial fibrillation and the studied factors was established.ConclusionDemographic characteristics have a significant impact on ablation efficiency, while the type of energy source does not.

Isolated left atrial cryoablation of atrial fibrillation in conventional mitral valve surgery

“…Nevertheless, the 1 and 5-year freedom from AF at follow-up of this experience (98.1% and 89.2%, respectively) were comparable (or compared favorably) with those of other studies of Literature [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] where either biatrial (75% to 91% and 80.2%, respectively) or isolated LA ablation (57.8% to 95% and 72% to 81.1%, respectively) was performed. The present authors have no convincing arguments to give reason of these good results, which were consistent with the higher rate of dismission of any anti-arrhythmic drug of this experience with respect to other experiences (97.3% vs. 63% to 88.4%, at 1 year from hospital discharge) [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] . These results were even more unexpected considering that the line connecting the left pulmonary veins box to the LA appendage was waived and that an endocardial purse-string suture was used to perform the LA appendage obliteration (when performed).…”

“…Actually, in the literature, there is a relative lack of information concerning specifically the ablation of AF in isolated MV surgery (i.e., not combined with aortic valve operations), and it is know that the probability of success of surgery of AF in the case of concomitant correction both of mitral and aortic valvulopathy is higher than that of concomitant treatment of mitral valve disease alone [21] . Also the higher rate of patients of the study who died in-hospital (5.9% [5.3% ± 5.2% by EuroSCORE II] vs. 0–3% of Literature [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] ), and the fact that these high-risk subjects were (obviously) excluded from the calculation of the nonparametric estimates of freedom from AF at follow-up, may have improved the results significantly. Incidentally, the increased rate of in-hospital deaths of the present study was ascribed by the authors to the frequent (21.2%) presence of ischemic heart disease among the causes of MV disease, to the high rate of urgent surgical priority (25.4%), and to the prolonged time of surgery (an average of 5 h).…”

“…According to this analysis, higher preoperative values of PAP systolic and hospital discharge on AF were associated with an increased risk of AF at follow-up; higher preoperative levels of PAP systolic were associated with an increased risk of recurrent AF. However, older age and comorbidities such as systemic hypertension, chronic obstructive pulmonary disease, and morbid obesity, as well as rheumatic etiology of MV disease, MV disease alone, cardiac (or MV) reoperation, permanent AF, long duration of AF (>10 years), LA dilation (>50, 50.5, or 70 mm), left ventricular dysfunction (LVEF < 37.5%), the CHA 2 DS 2 -VASc score and EuroSCORE II, the type of MV surgery, and residual/recurrent significant MV disease were not risk factors for AF at follow-up; the role of preoperative use of β-blockers as a predictor of success was not confirmed; the role of C-reactive protein (>12 mg/dl) and F-wave in V1 < 0.1 mV as predictor of failure was not evaluated because of the lack of the data [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] . The present authors have no convincing arguments to explain this fact, even though the limited number of patients enrolled in the study, the low frequency of the event of interest (recurrence of AF), the brief interval between AF-onset and cryoablation (median, 3 years), as well as the wide range of LA size could all have contributed significantly to the results.…”

“…The studies that included concomitant aortic valve operations were retained when the results of MV surgery alone had been explicitly reported (Suppl. Table S1) [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] .…”

The Factors Affecting Rhythm Control for Cryoablation of Atrial Fibrillation in Mitral Valve Surgery

“…In our study, TE events occurred only in three patients in the early postoperative period and no further TE events occurred in the six-month follow-up period. Vural et al [24] , in their recently published article (2018), have presented a comparison of cryoablation and radiofrequency ablation in MVS. They reported that there was no difference between the energy sources used for conversion to SR from AF.…”