A prospective randomized trial comparing biatrial and isolated left atrial ablation in patients with long-standing persistent atrial fibrillation undergoing CABG
Authors: Kalybekova A , Chernyavskyi A , Lukinov V 
Published: November 2020

Abstract

Purpose
To compare the efficacy and safety of left atrial ablation (LAA) with those of biatrial ablation (BA) in patients with long-standing persistent atrial fibrillation (AF) in common with CABG.

Background
AF is the most common heart rhythm disorder, while CAD is the most common cardiovascular disease. Chronic coronary syndrome and atrial fibrillation coexist in many patients. Long-standing persistent atrial fibrillation (AF) is frequent pathology in patients undergoing CABG. Surgical ablation in such patients is currently an effective treatment of AF. Pulmonary vein isolation (PVI) may reduce AF recurrences in 70% of patients with paroxysmal form of AF. However, the efficacy of ablation in patients with long-standing persistent AF is rather low. Clinical studies have shown that the right atrium can also be involved in the AF initiation and maintenance. Areas localized in both atrias are characterized by rapid electrical activity, which is critical in the AF persistence. Therefore, we have hypothesized that in long-standing persistent AF BA could be more effective than isolated LAA.

Methods
Between 2016 and 2019, 116 patients with long-standing persistent AF and CAD who underwent open-heart surgery were included in this single blind prospective randomized study and divided into two groups: 58 patients in group 1 underwent isolated LAA + CABG, and group II (58 patients) - BA + CABG. All the patients had Reveal LINQ ICM System (Medtronic, USA) implanted during the index procedure. The mean age was 65 [61; 67.75] years versus 62 [58; 66] years (p=0.050) and 83% versus 84% (p&gt;0.999) were men in BA and LAA groups, respectively. The follow-up time was 22±3 months for two groups. The primary endpoint was freedom from AF during 24-month follow-up based on 24-hour Holter monitoring ECG registration and Reveal device data.

Results
This study has demonstrated that in CAD patients with long-standing persistent AF, PVI in combination with multiple linear lesions in the right atrium while GABG produce a significantly higher success rate than PVI alone. After 24 months, AF recurred in 38% of patients in the BA group and in 64% – in the LAA group (p=0.010). Univariate logistic regression analysis showed indicators as long axis of left atria in mm (OR 3.45, 95%; CI 1.77 to 7.64, p=0.001) in LAA group and (OR 2.02, 95%; CI 1.03 to 4.26, p=0.049) in-group BA increases the risk of AF. Chronic kidney disease (OR 2.95, 95% CI 1.05 to 9.22, p=0,048), and mitral regurgitation (OR 1.18, 95% CI 1.01 to 1.41, p=0.047) have been found the independent predictors of AF recurrence in the LAA group. Arrhythmia on the third day after procedure increases the risk of AF (OR 3.79, 95% CI 1.45 to 10. 58, p=0.008) in the LAA group in a long-term follow-up.

Conclusion
The study has demonstrated that BA is more effective for treatment of long-standing persistent AF in CAD patients undergoing CABG.

Funding Acknowledgement
Type of funding source: None