Mobile health technology integrated care in older atrial fibrillation patients: a subgroup analysis of the mAFA-II randomised clinical trial

Background The Mobile Health Technology for Improved Screening and Optimized Integrated Care in AF (mAFA-II) randomised trial demonstrated the efficacy of a mobile health (mHealth) technology-implemented 'Atrial fibrillation Better Care' (ABC) pathway-approach (mAFA intervention) in reducing the risk of adverse events in patients with atrial fibrillation (AF). Whether these benefits also apply to older patients is unclear. In this ancillary analysis, we evaluated the effect of mAFA intervention among older AF patients. Methods The mAFA-II trial enrolled adult AF patients across 40 centres in China. For this analysis, we defined older patients as those aged >= 75 years. Primary outcome was the composite of ischemic stroke or thromboembolism, all-cause death and rehospitalisation. The effect of mAFA intervention was assessed through multivariable Cox-regression models. We also evaluated the interaction between age and effect of the mAFA intervention in the main trial population. Results In this analysis, we included 1,163 AF patients >= 75 years (mean age: 82.6 +/- 5.3 years, 43.1% females); 520 were allocated to mAFA intervention, 643 to usual care. mAFA intervention was associated with a significant reduction of the primary composite outcome (adjusted hazard ratio [aHR]: 0.58, 95% confidence interval [CI]: 0.35-0.97) and rehospitalisations alone (aHR: 0.47, 95%CI: 0.24-0.91). Significant interaction between age and mAFA intervention effect was observed for both the composite outcome (P = 0.002) and rehospitalisation alone (P = 0.015), with the effect decreasing as age increased, particularly among patients >= 80 years old. Conclusions A mHealth technology-implemented ABC pathway is effective in reducing adverse clinical outcomes in older AF patients. The benefits obtained with mAFA intervention were attenuated at extreme ages.