Adherence to physical activity in patients with serious heart disease is critical to recovery and survival. In-person programs to promote activity in cardiac patients have been poorly attended, and increasingly patients are focused on mobile, self-management-based approaches to health. Accordingly, we completed a one-arm trial of a novel one-way 14-day text message intervention among 40 patients
... [Show full abstract] with a prior acute coronary syndrome (ACS). The two-pronged psychological-behavioral intervention alternated daily messages focused on promoting psychological well-being with messages providing specific education/advice regarding physical activity. All messages were successfully transmitted, and nearly all participants found the intervention to be helpful (n = 37; 92.5%) and performed at least one specific health-related action in response to a text message (n = 35; 87.5%). Post-intervention, participants had improvements in happiness (Cohen’s d = 0.25), determination (d = 0.37), depression (d = −0.01), and anxiety (d = −0.13), though not optimism. Moreover, participants reported an increase in moderate physical activity of 105 min/week (baseline: 261 [SD 265] minutes/week, follow-up: 366 [SD 519]; d = 0.25). These improvements were largely maintained two weeks later, with further increases in physical activity (414 [SD 570] minutes/week). Text messaging focused on well-being and physical activity was well-accepted and associated with improvements in activity and mental health in this high-risk clinical population.