Health-related quality of life is an independent predictor of mortality and hospitalisations in transthyretin amyloid cardiomyopathy: a prospective cohort study.

ABSTRACT

PURPOSE: Transthyretin amyloid cardiomyopathy (ATTR-CM) is associated with severely impaired health-related quality of life (HRQL). HRQL is an independent predictor of outcome in heart failure (HF), but data on patients with ATTR-CM is scarce. This study therefore aims to evaluate the association of HRQL with outcome in ATTR-CM. METHODS: Patients from our prospective ATTR-CM registry were assessed using the Kansas City cardiomyopathy questionnaire (KCCQ), the Minnesota living with HF questionnaire (MLHFQ), and the EuroQol five dimensions questionnaire (EQ-5D). Cox regression analysis was utilised to assess the impact of HRQL on all-cause mortality. RESULTS: 167 patients [80 years; interquartile range (IQR) 76-84; 80.8% male] were followed for a median of 27.6 (IQR 9.7-41.8) months. The primary endpoint of all-cause mortality was met by 43 (25.7%) patients after a median period of 16.2 (IQR 9.1-28.1) months. In a univariate Cox regression for mortality, a 10-point change in the KCCQ implied a hazard ratio (HR) of 0.815 [95%-confidence interval (CI) 0.725-0.916; p = 0.001], in the EQ-5D VAS of 0.764 (95%-CI 0.656-0.889; p < 0.001), and 1.163 (95%-CI 1.114-1.433; p < 0.001) in the MLHFQ. After adjustment for established biomarkers of HF, all-cause mortality was predicted independently by the EQ-5D VAS (HR 0.8; 95%-CI 0.649-0.986; p = 0.037; per 10 points) and the MLHFQ (HR 1.228; 95%-CI 1.035-1.458; p = 0.019; per 10 points). CONCLUSION: HRQL is a predictor of outcome in ATTR-CM. The EQ-5D VAS and the MLHFQ predict survival independent of biomarkers of HF.

Patients with transthyretin amyloid cardiomyopathy, a condition causing heart failure and mostly seen in the elderly, suffer from shortness of breath and reduced maximum physical performance. Disease assessment is currently based on blood analysis for markers of heart failure. However, standardised patient questionnaires also allow to estimate disease severity. In this study, we analyse different standardised patient questionnaires for their ability to predict adverse events including death and heart failure-related hospitalisations. The analysis demonstrates that an increase of ten points in the Kansas City Cardiomyopathy questionnaire, a tool specifically designed for patients with heart failure, implies a reduction of mortality risk of close to 20%. Interestingly, even the very simple visual analogue scale, a quality-of-life measurement tool which asks the patient to rate their health on a scale from zero (worst) to one hundred (best) has demonstrated remarkable predictive utility. An increase of ten points on this scale resulted in a reduction of risk for death from any cause of almost a quarter. This analysis suggests that standardised patient questionnaires for the assessment of quality of life may play an important role in the evaluation of patients with transthyretin amyloid cardiomyopathy and estimation of prognosis.