Exercise Test Predictors of Late Recurrence of Atrial Fibrillation After Catheter Ablation

Jakub Hejc1, Richard Redina2, Tomas Kulik1, Martin Pesl3, Zdenek Starek4
1International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic, 2International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic 2 Department of Biomedical Engineering, Brno University of Technology, Brno, Czech Republic, 3Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic 2 ICRC, St. Anne’s University Hospital, Brno, Czech Republic 3 1st Department of Internal Medicine, Cardio-Angiology, Faculty of Medicine, Masaryk University, Brno, Czech Republic, 4International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic 2 1st Department of Internal Medicine, Cardio-Angiology, Faculty of Medicine, Masaryk University, Brno, Czech Republic


Abstract

Aims: Freedom from atrial fibrillation (AF) at 1 year is estimated to be between 55–80% of patients undergoing catheter ablation. A significant number of patients would require repeat procedures due to recurrent AF. Identification of patients at higher risk for developing recurrent AF can help in building better preventive strategies and post-ablation rhythm control therapy. The aim of this study was to identify the exercise-based risk factors associated with the first recurrence of AF between 3 and 48 months following the ablation.

Methods and results: Patients (n=97, 59±10 years, 67.5% men) referred for catheter ablation of paroxysmal AF underwent simultaneous exercise echocardiography and direct invasive left atrial pressure (LAP) measurements at rest and at the peak of arm exercise. After the index ablation procedure, follow-up visits were scheduled at 1, 3, 6, 12, 24 and 36 months. The observed freedom from AF recurrence during the follow-up was 72.2 %. Among echocardiographic and excercise-based parameters, multivariate-adjusted analysis revealed metabolic equivalent of task (MET) as a good predictor of late AF recurrence (AUC=0.79). Patients were divided into two groups based on the optimal MET threshold value estimated by using the binary logistic model. Patients with METs > 3.7 kcal∙kg-1∙h-1 were further used as the control group. Within the two groups, multivariate Cox proportional hazard regression (concordance 0.79) demonstrated that two clinical variables were related to major increase in hazard ratio (HR) of the late recurrence of AF: (1) decreased metabolic equivalent task unit (hazard ratio 6.66, p=0.01) and (2) male sex (HR 4.35, p=0.03).

Conclusion: In patients with paroxysmal AF undergoing catheter ablation, decreased exercise capacity and sex are strong predictors of late AF reccurence after pulmonary vein isolation.