Background: Thoracoscopic ablation is an effective treatment of patients with atrial fibrillation. Nowadays, 2 types of ablative devices are available in clinical practice allowing one to perform the thoracoscopic procedure - Medtronic and AtriCure. However, the contemporary clinical literature does not have enough data that would compare these two approaches.

Aims: to perform a comparative analysis of the short-term results of two minimally invasive strategies in thoracoscopic ablation for atrial fibrillation.

Methods:

The retrospective study was performed in which included 232 patients underwent thoracoscopic ablation for atrial fibrillation in two clinical centers for the period from 2016 to August 2021. The patients were divided into 2 groups. The first group was represented by those patients to whom a Medtronic device was applied (n=140), the second group was treated with an AtriCure device (n=92). The patients were comparable in their age, gender, initial severity of the condition. The follow-up consisted of laboratory tests, chest Х-ray, electrocardiography, 24-hour Holter monitor, echocardiography. The structure and prevalence of intraoperative and postoperative complications, specifics of the postoperative period were compared between the two groups.

Patients of the thoracoscopic group were divided into 3 subgroups: I - low (no HF), II - medium (possible) and III - high risk of HF (HF confirmed) (Table 1). A statistically significant difference was found for the indicator: age (in the "high probability" group in relation to the "low probability" group by an average of 5.5 years; p=0.002) (Table 1). The clinical characteristics of patients in the studied subgroups are presented in Table 2, no significant difference was found for any of the compared indicators.

The nature of the cardiac arrhythmia and the severity of clinical symptoms are presented in Table 3. Significant differences were obtained for the following indicators: CHADS2VASc (in group III, "high probability" in relation to group I, "low probability" by an average of 1 point; p=0.008); HFA-PEFF (in group III, "high probability" by relative to group I "low probability" by an average of 5 points; p<0.001). Also, significant dynamics was obtained by the frequency of diagnosis of paroxysmal and long-lasting persistent forms of AF (p=0.025). Significant differences were obtained in the number of patients with 3 FC of heart failure (in group III, compared with group I, 5.3% vs 0.0%, respectively)

Inclusion Criteria:

• persistent or long-lasting persistent form of atrial fibrillation;
• age over 18 years;
• failure of conservative therapy with the use of Class I and III antiarrhythmic drugs (Vaughan Williams classification);
• absence of marked structural pathology of the heart, requiring surgical treatment.

Exclusion Criteria:

• secondary atrial fibrillation due to reversible cause (pericarditis, hyperthyroidism, TELA, pneumonia, hypokalemia, etc.);
• surgical interventions on thoracic or mediastinal organs;
• age less than 18 years;
• presence of indications for open heart surgery under conditions of artificial circulation;
• heart failure with ejection fraction less than 30%;
• acute cerebral circulation disorder less than 3 months old;
• acute myocardial infarction or coronary stenting less than 3 months old;
• active systemic infection;
• left atrial appendage thrombosis detected one day before surgery;
• hemodynamically significant atherosclerotic lesion of coronary arteries and myocardial ischemia at the time of indications for surgery (confirmed by functional tests and coronarography);
• presence of contraindications for direct and indirect anticoagulants;
• presence of concomitant diseases of other organs and systems, which can lead to death within the first 2 years after the operation.

There is no current plan to share individual participant data (IPD).