Predicting Heart Failure Outcomes Using Patient-Reported Health Status

Background: The Kansas City Cardiomyopathy Questionnaire-12 (KCCQ-12), a patient-reported outcome measure for adults with heart failure, is associated with hospitalizations and mortality in clinical trials. Curated datasets from controlled trials differ substantially from pragmatic data collected from real-world settings, however, and few data exist on the KCCQ-12’s predictive utility in clinical practice. Objectives: To evaluate the predictive utility of the KCCQ-12 for hospitalizations and mortality when administered during outpatient heart failure care. Methods: We conducted a cohort study of patients assigned the KCCQ-12 in heart failure clinics from July 2019 through March 2024. The primary exposure was KCCQ-12 Overall Summary (KCCQ-OS) score. The primary outcomes were 90-day hospitalization and cumulative mortality. Multivariable-adjusted associations were assessed using logistic regression and Cox proportional hazards models. Gradient boosting (XGBoost) and random survival forest (RSF) machine learning models were used to evaluate KCCQ-OS feature importance in predicting 90-day hospitalizations and cumulative mortality, respectively. Results: Among 4,406 patients assigned the KCCQ-12, 2,888 (66%) completed at least one questionnaire. The median KCCQ-OS score was 59.4 (IQR 35.4–81.8). Patients with KCCQ-OS scores <25 had higher adjusted risks of 90-day hospitalization (OR 3.49, 95% CI 2.50-4.90) and cumulative mortality (HR 3.09, 95% CI 2.29–4.17) compared to those with scores ≥75. The KCCQ-OS score was the most important feature for predicting 90-day hospitalizations in the XGBoost model (AUC 0.760, 95% CI 0.706–0.811) and the most important feature for predicting cumulative mortality in the random survival forest model (C-index 0.783, 95% CI 0.742–0.824) compared to other clinical, demographic, and laboratory variables. KCCQ-12 non-completion was independently associated with increased 90-day hospitalization (OR 1.72, 95% CI 1.46–2.02) and 1-year mortality (HR 1.52, 95% CI 1.25–1.84) after adjusting for all variables in the primary analysis. Conclusions: In outpatient heart failure care, lower KCCQ-OS scores were strongly associated with increased hospitalizations and mortality, with the greatest risk among patients with scores <25. Non-completion of the KCCQ-12 was itself associated with worse outcomes. The KCCQ-OS score was the dominant predictor of 90-day hospitalizations and cumulative mortality in machine learning models, supporting the KCCQ-12 as a prognostic tool in routine clinical practice.