Wern Yew Ding, MBChB

Kuck KH, Lebedev DS, Mikhaylov EN, Romanov A, Gellér L, Kalējs O, Neumann T, Davtyan K, On YK, Popov S, et al. Catheter ablation or medical therapy to delay progression of atrial fibrillation: the randomized controlled atrial fibrillation progression trial (ATTEST). Europace. 2021;23:362-369.

Atrial fibrillation (AF) is closely linked to atrial cardiomyopathy and associated with structural and electrical remodelling that develops as the condition progresses. Currently, AF is classified based on a crude assessment of the estimated duration of each episode. Progression of AF is often signalled by an increase in AF burden, which is related to poorer outcomes, including excess thromboembolism. Therefore, halting (or even reversing) AF progression is of clinical importance.

In this study by Kuck and colleagues, the authors investigated whether catheter AF ablation could delay the progression of AF compared with drug therapy. To this end, they performed a study among patients aged equal or over 60 years old with symptomatic paroxysmal AF who were randomized to either radio frequency catheter ablation (RFCA) or anti-arrhythmic drug (AAD) therapy. The study was terminated prematurely due to slow enrolment; at the time of termination, 255 (79%) of the planned 322 patients were enrolled. Over a follow-up period of 3 years, the primary endpoint for the rate of persistent AF or atrial tachycardia was significantly lower with RFCA compared to AAD therapy (2.4% vs. 17.5%). The rate of any recurrent AF or atrial tachycardia was also significantly lower with RFCA over AAD therapy (49.2% vs. 84.8%). Serious adverse events occurred in 12 (11.8%) patients in the radiofrequency ablation arm.

Overall, the findings are consistent with the increasing amount of evidence to support the role of catheter AF ablation over AAD therapy, and may provide an explanation for the improved prognosis associated with catheter AF ablation in observational studies. However, it should be noted that of 1237 patients who were screened for eligibility, only 255 (20.6%) were included. Therefore, the results are derived from a highly selected cohort of patients who remained in paroxysmal AF despite having been diagnosed with AF about 4 years prior. Furthermore, there was a substantial dropout rate in the study, and electrocardiographic monitoring was conducted using trans-telephonic monitoring (TTM) on a monthly basis from day 300 onwards, which may have led to missed events (weekly TTM before day 300).