Variability in the clinical status of patients with advanced heart failure

Background: The importance of repeated clinical assessments of patients with heart failure is widely accepted. The frequency of such follow-up is not established and is likely to depend on the natural history and variability of patients' health status and the availability and use of appropriate treatments. Methods and Results: We analyzed data from a multicenter prospective cohort study of heart failure outpatients comparing baseline variables including New York Heart Association (NYHA) class, summary score on the Kansas City Cardiomyopathy Questionnaire (KCCQ), and performance on a 6-minute walk test with results of a repeat evaluation at 6 weeks. We also compared patient and physician assessment of change in disease status among patients with advanced symptoms (NYHA class III with a recent antecedent hospitalization or class IV) and those with milder degrees of limitation (NYHA classes I, II, and stable III). Patients with advanced symptoms had greater short-term variability in health status as reflected by the KCCQ summary score and a visual analog scale. A greater proportion of patients with advanced heart failure experienced moderate or greater clinical change. Patient and physician global assessments were congruent with more direct measures of health status. Conclusion: Patients with advanced heart failure have greater short-term variability in status, supporting the need for frequent clinical follow-up and appropriate power calculations for clinical trials that are designed to measure meaningful changes over a short period.