Purpose: In patients with ischemic heart disease, the objectives were (1) to explore associations between patient-reported outcomes, sociodemographic, and clinical factors at discharge and 1-year all-cause mortality and (2) to investigate the discriminant predictive performance of the applied patient-reported outcome instruments on 1-year all-cause mortality. Methods: Data from the Danish national DenHeart cohort study were used. Eligible patients (n = 13,476) were invited to complete a questionnaire-package, of which 7167 (53%) responded. Questionnaires included the 12-item Short form health survey (SF-12), Hospital anxiety and depression scale (HADS), EQ-5D, HeartQoL, Edmonton symptom assessment scale (ESAS), and ancillary questions on, e.g., social support. Clinical and demographic characteristics were obtained from registers, as were data on mortality. Comparative analyses were used to investigate differences in patient-reported outcomes. Mortality associations were explored using multifactorially adjusted Cox regression analyses. Predictive performance was analyzed using receiver operating characteristics (ROC). Results: Patient-reported outcomes at discharge differed among those alive versus those deceased at one year, e.g., depression (HADS-Depression ≥ 8) 19% vs. 44% (p < 0.001). Associations with 1-year mortality included feeling unsafe about returning home from the hospital; hazard ratio (HR) 2.07 (95% CI 1.2–3.61); high comorbidity level, HR 3.6 (95% CI 2.7–4.8); and being unmarried, HR 1.60 (95% CI 1.33–1.93). Best predictive performance was observed for SF-12 physical component summary (Area under the curve (AUC) 0.706). Conclusion: Patient-reported health, sociodemographic, and clinical factors are associated with 1-year mortality. We propose systematic screening with robust predictive tools to identify patients at risk and healthcare initiatives to explore and offer effective treatment to modify patient-reported health indicators.