Predictive utility of health-related quality of life and the 6-minute walking test in transthyretin amyloid cardiomyopathy - a comparison

Abstract Introduction Both health-related quality of life (HR-QoL) as well as submaximal physical performance as assessed using the 6-minute walking test (6-MWT) have been shown to predict outcome in heart failure. However, it is currently unclear how the predictive utility of different HR-QoL measurement tools compares to the 6-MWT in transthyretin amyloid cardiomyopathy (ATTR-CM). Aims To evaluate predictive utility of the Kansas City Cardiomyopathy Questionnaire (KCCQ), the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and the EuroQol Five Dimensions Questionnaire (EQ-5D) in comparison to the 6-MWT in patients with ATTR-CM. Methods and results 186 patients diagnosed with ATTR-CM were included and data from 474 visits (2.55 per patient) was analysed. All scores and distance walked in the 6-MWT were transformed into Z-values by subtracting the mean and dividing by the standard deviation. In a cox regression analysis for all-cause mortality adjusted for age and sex, the KCCQ [Hazard Ratio (HR): 0.560, p = < 0.001], the EQ-5D visual analogue scale (HR: 0.712, p = 0.005) and the MLHFQ (HR: 0.613, p = < 0.001) proved predictive of outcome. For heart failure hospitalisation, the KCCQ (HR: 0.455, p = < 0.001), the EQ-5D overall score (HR: 0.753, p = 0.007), the EQ-5D visual analogue scale (HR: 0.631, p = < 0.001) and the MLHFQ score (HR: 0.466, p = < 0.001) were shown to be of high predictive utility. In comparison, the 6-MWT HRs were 0.434 and 0.544 for mortality and heart failure hospitalisation, respectively (p = < 0.001). Conclusion Prognostic utility of the KCCQ and MLHFQ scores is non-inferior to the 6-MWT in ATTR-CM. While much more simplistic, the EQ-5D is lacking behind the other tested questionnaires with regard to predictive utility.