Smartphone app-based approximation of time spent with atrial fibrillation and symptoms in patients after catheter ablation: Data from the TeleCheck-AF project

Aims: Reduction of atrial fibrillation (AF) burden is the preferred outcome measure over categorical AF rhythm recurrence after AF ablation. In this sub-analysis of the TeleCheck-AF project, we tested the feasibility of smartphone app-based approximation of time spent with AF and/or symptoms. Methods and results: Patients scheduled for at least one teleconsultation during the 12-month follow-up after AF ablation were instructed to use a smartphone photoplethysmography-based application for simultaneous symptom and rhythm monitoring three times daily for 1 week. Proxies of time spent with AF and/or symptoms (% recordings, load, and % days), temporal aggregation of AF and/or symptoms (density), and symptom-rhythm correlation (SRC) were assessed. In total, 484 patients (60% male, 62 ± 9.9 years) were included. Adherence, motivation, and patient satisfaction were high. %AF recordings, AF load, and %AF days (rs = 0.88-0.95) and %symptom recordings, symptom load, and %symptom days (rs = 0.95-0.98) showed positive correlations. The SRC correlated negatively with time spent with symptoms (rs = -0.65-0.90) and with time spent with AF (rs = -0.31-0.34). In patients with paroxysmal AF before ablation and AF during the monitoring period, 87% (n = 39/44) had a low-density score <50% ('paroxysmal AF pattern') while 5% (n = 2/44) had a high-density score >90% ('persistent AF pattern'). Corresponding numbers for patients with persistent AF before ablation were 48% (n = 11/23) and 43% (n = 10/23), respectively. Conclusion: On-demand, app-based simultaneous rhythm and symptom assessment provides objective proxies of time spent with AF and/or symptoms and SRC, which may assist in assessing AF and symptom outcomes after AF ablation.