Value of transoesophageal echocardiography-guided approach to electrical cardioversion of atrial fibrillation

Abstract

Electrical cardioversion (ECV) of atrial fibrillation (AF) may be associated with thromboembolism. For thromboembolism prevention both transoesophageal echocardiography (TOE) performed for left atrial thrombi detection and anticoagulation with oral anticoagulants (OAC) for 3 weeks before cardioversion are recommended, but there is lack of clinical evidence for real efficiency of such anticoagulation.

Objectives: The goal of our study was to assess the necessity of TOE in all patients with non-valvular persistent AF after four weeks of OAC therapy before ECV.

Materials and Methods: A total of 118 consecutive patients with non-valvular persistent atrial fibrillation, who underwent TOE before ECV in Dnipropetrovsk Regional Clinical Centre of Cardiology and Cardiosurgery in 2011 - 2012 years, were included in the study.

Results: The mean age of participants was 60,3 ± 0,9 years (SD=9,3), and 84 (71,4%) were men. Among them, 70 (59,3%) patients had arterial hypertension, 9 (7,6%) - coronary artery disease, 31 (26,3%) - combination of coronary artery disease and arterial hypertension, 4 (3,4%) - cardiomyopathy, 69 (58,5%) persons were obese. Mean term of last AF episode was 146 ± 43,4 days. EHRA I class was presented in 5 (4,2%) patients, EHRA II in 72 (61,0%) patients and EHRA III - in 41 (34,8%) patients. The majority of the participants - 78 (66,1%) fell into the high-risk group as CHA2DS2-VASc score of ≥ 2; 34 (28,8%) patients were in the moderate-risk group and 6 (5,1%) persons had CHA2DS2-VASc score of 0. Transthoracal echocardiography and TOE were done in all patients after at least 3 weeks of effective OAC therapy. Precardioversion TOE detected left atrial appendage thrombi in 31 (26,3%) patients, right atrial appendage thrombi in 8 (6,8%) patients, both left and right atrial appendages thrombi in 59 (50,0%) patients after four weeks of effective anticoagulation. Only 20 (16,9%) patients with persistent non-vlvular AF had no thrombi in atrial appendages according to TOE data. No one had thrombi identification in atrial chambers. Spontaneous echocontrast was detected in all patients. ECV was performed in 48 (40,6%) patients with organized thrombi and in 20 patients without thrombi in atrial appendages. In 50 (51%) patients with non-organized thrombi procedure was deffered, that shows inefficiency of 4 weeks of anticoagulant therapy in these patients. No patient with organized thrombi in atrial appendages developed cardioversion-related thromboembolism. Correlation analysis showed association between thrombi in atrial appendages and age (r = 0,21; р < 0,03), obesity (r = 0,23; р < 0,02), NYHA functional class of heart failure (r = 0,29; p < 0,01), CHA2DS2 –VASc score (r = 0,19; p < 0,04), left atrial volume in diastole (r = 0,18; p < 0,05), inverse correlation was found between first diagnosed AF and atrial appendages thrombi (r = -0,25; p < 0,01).

Conclusions: TOE should be performed in all patients with non-valvular AF after four weeks of anticoagulation before ECV, because it gives the opportunity to identify patients for prolonged course of OAC therapy.

Key words: atrial fibrillation, thromboembolism, transoesophageal echocardiography, electrical cardioversion.