Potential legacy effect of digital therapeutics on mortality in CHD patients treated with PCI: 8-Year result of BAMA trial

Background: The original BAMA randomized trial showed that a mobile app-based self-management digital therapeutics (DTx) intervention improved medication adherence and cardiovascular risk-factor control at 12 months in patients with coronary heart disease (CHD). Whether these early benefits are associated with favorable long-term outcomes-a potential legacy effect-remains uncertain. Methods: The BAMA pilot trial was a parallel-group, open-label, single-center randomized controlled trial in which 300 patients with CHD were assigned 1:1 to regular follow-up with or without DTx. The present study was a 12-month landmark post-trial analysis with follow-up through June 2025, corresponding to up to 8 years after randomization. Participants in the landmark cohort were analyzed according to original randomized assignment. Cox models evaluated all-cause and cardiovascular mortality, with Firth penalized Cox regression as a sparse-event sensitivity analysis. Longitudinal lipid trajectories were assessed using linear mixed-effects models based on actual measurement timing. Results: Among 290 participants who completed the 12-month visit, 289 had ascertainable post-landmark follow-up. During a median post-trial follow-up of 7.1 years, 22 participants died, including 13 from cardiovascular causes. After adjustment for baseline age and sex, original DTx assignment was associated with lower all-cause mortality (hazard ratio [HR], 0.38; 95% CI, 0.15-0.98; P=.045) and cardiovascular mortality (HR, 0.19; 95% CI, 0.04-0.87; P=.032). Firth penalized analyses yielded directionally consistent results. No significant group-by-time interactions were observed for total cholesterol, triglycerides, high-density lipoprotein cholesterol, or low-density lipoprotein cholesterol. Conclusions: Original DTx assignment was associated with lower post-landmark all-cause and cardiovascular mortality despite broadly comparable longitudinal lipid trajectories. These findings may be consistent with a potential legacy effect and warrant confirmation in larger prospective studies.