Surgery for arrhythmias and congenital heart disease: is the combined approach effective?

Adults with congenital heart disease (ACHD) are a growing population. The incidence of rhythm disturbances in these patients is approximately 3 times higher than in the general population. In ACHD, arrhythmias are a major cause of morbidity and mortality, and a common reason for hospital admission. Referral for arrhythmias, mainly supraventricular, accounts for 31% of hospital admissions, and the prevalence increases with the age of the patient and with time since cardiac surgery [1, 2]. ACHD with supraventricular arrhythmias have an increased risk of mortality, and the most common causes of death are progressive heart failure, sudden death and death associated with thromboembolic complications [3]. Treatment strategies for arrhythmias in ACHD include pharmacological therapy, catheter ablation, device therapy and surgery. Today, surgery is indicated for patients in whom the catheter ablation technique fails or for patients with associated structural cardiac defects requiring concomitant surgery [4]. The article by Ramdjan et al. [5] from Rotterdam, The Netherlands, reports the outcomes of concomitant arrhythmia surgery and repair of congenital heart defects in 66 consecutive adult patients with a mean age of 56 years during a period of 16 years (from 2001 to 2017). The patients had various congenital defects, most of which were right-sided congenital diseases, and 70% of patients came for surgery with natural history without prior palliative or corrective cardiac surgery. Atrial fibrillation (AF) was present in 70% of patients, atrial flutter or intra-atrial re-entry tachycardia in 9% of patients and a combination of AF and atrial flutter/intra-atrial re-entry tachycardia in 21% of patients. The arrhythmia was treated with a combination of incisions and lesions using different energy sources. They performed only left maze in 51% of patients, right and left maze in 29%, right maze in 8% and other approaches in the remaining 12%. In a mean follow-up of 2 years, there was an early recurrence rate of AF of 67% and a late recurrence rate of AF of 45%. In an univariate analysis, the authors have been able to identify the age at surgery, prior (longstanding) persistent AF and atrial congenital heart defects as possible risk factors for the recurrence of arrhythmias after surgery. In a multivariate analysis, they reported only the age at arrhythmia surgery as an independent predictor for late AF recurrence. We should congratulate the authors on the effort made on the therapeutic management of these patients. The approach to combine elective cardiac surgery and arrhythmia surgery is frequently used in experienced adult cardiac surgery centres, but ACHD, especially those with anatomical variants, represent very complex patients with anatomical situations that do not exist in normal hearts where the ablation techniques have been standardized. This can explain why arrhythmias in ACHD remain difficult to treat. I agree with the authors on the fact that the management of these patients needs a multidisciplinary team to which, however, I suggest that an electrophysiologist must necessarily be part of the team. The electrophysiologist is one who should guide the surgeon in the choice of lesions, incisions and correct approach. I was a little surprised by the incidence or recurrence of arrhythmias in these series, which is quite higher than previous reports [4, 6–8]. I do not think that this depends on the heterogeneity of the patients (these are the typical adult patients with congenital heart disease) but rather on the variability of the treatment. It is not clear what kind of protocol has been applied. When and why a right maze or a left and right maze should be performed are crucial points in the surgical treatment of arrhythmias and the number of lesion lines. Once again, I believe the collaboration with the electrophysiologists is fundamental in terms of preoperative diagnosis, imaging, approach and results. Another very important aspect is the choice of the energy source. The authors used radiofrequency, high-intensity focused ultrasound, microwave and cryothermal energy, but the criteria underlying the choice are not reported. The latest recent studies by Ad et al. [9] on the surgical treatment of AF seem to demonstrate the superiority of the cryothermal energy on radiofrequency. In my experience, after using the irrigated radiofrequency for many years, now I use only the cryothermal energy, and the new systems available make this technique easy and safe to perform. Finally, I do not find expressed in the paper what is done for the left atrial appendage in cases of AF. The definitive and complete exclusion of the left atrial appendage is an integral part of the surgical approach of arrhythmias, especially in cases of AF. This is performed not only to reduce the risk of thromboembolic events in case of AF recurrence but also to stop the anticoagulation therapy in cases of stable postoperative sinus rhythm. It is interesting to see that the authors identify the preoperative length of AF and the age of the patients as risk factors for the arrhythmia recurrence. As I have previously reported [4, 10], the duration of preoperative arrhythmias seems to have the most important adverse impact on postoperative arrhythmia recurrence. We can only speculate that these patients are referred for surgical treatment very late. Surgery for arrhythmia currently plays the smallest role in the treatment strategies of arrhythmias in adult patients with congenital heart disease but due to the growing arrhythmia load in these patients, we believe that incorporation of antiarrhythmic concepts into primary or particularly redo surgery should be highly considered, at least in specialized centres.