Relation of Longitudinal Changes in Quality of Life Assessments to Changes in Functional Capacity in Patients With Heart Failure With and Without Anemia

Abstract

Clinical status in heart failure is conventionally assessed by the physician's evaluation, patients' own perception of their symptoms, quality of life (QoL) tools, and a measure of functional capacity. These aspects can be measured with tools such as the New York Heart Association functional class, QoL tools such as the EuropeanQoL-5 dimension, the Kansas City Cardiomyopathy Questionnaire, patient global assessment (PGA), and by 6-minute walk test (6MWT), respectively. The ferric carboxymaltose in patients with heart failure and iron deficiency (FAIR-HF) trial demonstrated that treatment with intravenous ferric carboxymaltose in iron-deficient patients with symptomatic heart failure with reduced left ventricular function, significantly improved all 5 outcome measures. This analysis assessed the correlations between the longitudinal changes in the measures of clinical status, as measured by QoL tools and the changes in the measures of functional capacity as measured by the 6MWT. This analysis used the database from the FAIR-HF trial, which randomized 459 patients with chronic heart failure (reduced left ventricular ejection fraction) and iron deficiency, with or without anemia to ferrous carboxymaltose or placebo. The degree of correlation between QoL tools and the 6MWT was assessed at 4, 12, and 24 weeks. The data demonstrate highly significant correlations between QoL and functional capacity, as measured by the 6MWT, at all time points (p <0.001). Changes in PGA, Kansas City Cardiomyopathy Questionnaire, and EuroQoL-5D correlated increasingly over time with changes in 6MWT performance. Interestingly, the strongest correlation at 24 weeks is for the PGA, which is a simple numerical scale (r = -0.57, p <0.001). This analysis provides evidence that QoL assessment show a significant correlation with functional capacity, as measured by the 6MWT. The strength of these correlations increased over time.