Cardiac rehabilitation (CR) following myocardial infarction is vastly underused. As such, the aim of this study was to test a digital health intervention (DHI) as an adjunct to CR. Patients undergoing standard Mayo Clinic CR were recruited prior to CR ( n = 25) or after 3 months CR ( n = 17). Changes in risk factors and rehospitalizations plus emergency department (ED) visits were assessed after 3 months. Patients assigned to DHI during CR had significant reductions in weight (−4.0 ± 5.2 kg, P = .001), blood pressure (−10.8 ± 13.5 mmHg, P = .0009), and the group using DHI after 3 months of CR had significant reductions in weight (−2.5 ± 3.8 kg, P = .04) and systolic BP (−12.6 ± 12.4 mmHg, P = .001) compared to the control groups. Both DHI groups also displayed significant reductions in rehospitalizations/ED visits (−37.9 %, P = 0.01 and −28 %, P = .04, respectively). This study suggests that a guideline-driven DHI CR program can augment secondary prevention strategies during usual CR by improving risk factors for repeat events.