PURPOSE: Heart rate variability biofeedback (HRV-BF) is an effective psychophysiological intervention, with short-term effects of increased autonomic nervous system homeostasis, strengthened baroreflex sensitivity, and decreased hostility in patients with coronary artery disease (CAD). The study examined the 1-year HRV-BF effect on cardiovascular prognosis of these patients. METHODS: Of 222 patients with CAD referred by cardiologists, 210 were screened and randomly assigned to the HRV-BF and control groups. All patients received psychophysiological assessment and completed psychological questionnaires at pre- and post-interventions and 1-year follow-up. The cardiovascular prognosis primary endpoints included hospital readmission, emergency revisits, and mortality. RESULTS: The HRV-BF group had fewer all-cause readmissions (12.00 vs. 25.42%) and all-cause emergency visits (13.33 vs. 35.59%) than the control group. The low-frequency HRV in the HRV-BF group increased at post-intervention and 1-year follow-up compared with that at pre-intervention. Although no significant interaction effect was found in the standard deviation of the normal-to-normal intervals (F = 2.96, p = 0.055), it increased by 26.68% from pre- to post-intervention and 15.77% from pre-intervention to follow-up in the HRV-BF group. However, it decreased by 3.60% from pre- to post-intervention and increased by 1.99% from pre-intervention to follow-up in the control group. Depression and hostility scores decreased significantly at post-intervention and 1-year follow-up only in the HRV-BF group. CONCLUSIONS: The long-term HRV-BF effect was confirmed by improved cardiovascular prognosis, increased cardiac autonomic homeostasis and baroreflex sensitivity, and decreased depression and hostility. HRV-BF is an effective psychophysiological intervention with short- and long-term effects in cardiac rehabilitation programs.