Comparison of standard of care and pre-cardioversion heart rhythm monitoring using smartphone PPG (SMARTBEATS-RCT) - a randomized clinical trial

Scheduled cardioversion is a common and resource-intensive procedure in rhythm treatment of atrial fibrillation and atrial flutter. Cancellations of cardioversion procedures are common due to spontaneous conversion to sinus rhythm.

The aim of this study was to study the efficacy and feasibility of pre-cardioversion rhythm monitoring using smartphone photoplethysmography as compared to standard of care in scheduled cardioversion of atrial fibrillation.

Randomized, controlled, single-blinded study at a single center in a tertiary hospital.

Adult patients with persistent atrial fibrillation or atrial flutter scheduled for cardioversion were included. Pre-cardioversion ambulatory heart rhythm monitoring using smartphone photoplethysmography and reminders to support adherence to anticoagulation was applied in the intervention group as compared to standard of care (no active monitoring). Heart rhythm recordings were encrypted and transferred following recording and overread daily. A one-lead ECG recording was made simultaneous to each photoplethysmography recording for validation purposes. In case of spontaneous conversion to sinus rhythm in the intervention group, participants were contacted and cardioversion was canceled. In the control group, no further action was taken in case of rhythm conversion.

The primary efficacy outcome was proportion of same-day cancellations of scheduled atrial fibrillation or flutter cardioversions.

Among 369 contacted patients, 286 responded and 207 accepted participation and attended an inclusion visit, of which 206 were randomized. There were 105 participants assigned to intervention, and 101 assigned to standard of care. Three participants were excluded after randomization due to having a cardiac implantable device, leaving 104 and 99 participants for final analysis in the intervention and control group, respectively. Median age was 69.7 years and 27.7% were female. The participants performed 5226 heart rhythm recordings pre-cardioversion and the median number of daily recordings per participant pre-cardioversion was 2.1.

There were 4.8% (5/104) same-day cancellations of scheduled cardioversions in the intervention group compared to 23.2% (23/99) in the control group (P < .001). For same-day cancellations due to spontaneous sinus rhythm conversion, the corresponding results were 1.0% (1/104) versus 18.2% (18/99) (P < .001), relative risk reduction (RRR) 94,7%, absolute risk reduction (ARR) 17,2 % and number needed to treat (NNT) was 6.

Pre-cardioversion monitoring using smartphone PPG represents an easy-to-use and highly disseminated digital intervention significantly reducing same-day cancellations.

Difference cardioversion cancellations.