Feasibility of repeated on-demand smartphone app–based approximation of time spent with atrial fibrillation and symptoms in patients after catheter ablation: Data from the ISOLATION study

BACKGROUND: The preferred outcome after atrial fibrillation (AF) ablation is reducing AF burden, reflected by time spent with AF. Digital tools provide novel strategies to approximate time spent with AF. OBJECTIVES: The purpose of this study was to assess the feasibility of repeated on-demand heart rhythm and symptom monitoring and analyze time spent with AF and symptoms over 12 months after AF ablation. METHODS: Patients were instructed to monitor heart rhythm and symptoms using an on-demand photoplethysmography-supported smartphone application 3 times daily for 7 days at 3-, 6-, and 12-month follow-ups. Metrics assessed included AF load and density, symptom load and density, and symptom-rhythm correlation. RESULTS: A total of 191 patients (median age 65 years [interquartile range 58-71 years]) 65% (n = 125/191) male) were included. Patient adherence (-7%; P=.04) declined slightly over 12 months. Forty-five patients (24%) had AF recurrence and 136 (71%) symptom recurrence. Among patients with high AF load and density at 3 months, 73% (n = 11/15) and 88% (n = 7/8) remained in the respective high class; among patients with low AF load and density, 0% (n = 0/1 respective n = 0/1) remained in the low class. Among patients with high symptom load and density, 84% (n = 36/43) and 75% (n = 15/20) remained in the respective high class; among patients with low symptom load and density, 0% (n = 0/12 respective n = 0/2) remained in the low class. Symptom-rhythm correlation was high (median 97% [interquartile range 77%-100%]). CONCLUSION: Repeated on-demand smartphone-based monitoring is feasible after AF ablation. Patient adherence declined slightly over 12 months. At 3 months, high AF and symptom load reliably predicted the following year while low AF and symptom load necessitate repeated monitoring.