Association of Functional and Health Status Measures in Heart Failure

Jonathan Myers, Nayma Zaheer, Susan Quaglietti, Rupa Madhavan, Victor Froelicher, Paul Heidenreich
2006 Journal of Cardiac Failure  
A wide variety of instruments have been used to assess the functional capabilities and health status of patients with chronic heart failure (I-F), but it is not known how well these tests are correlated with one another, nor which one has the best association with measured exercise capacity. Methods and Results: Forty-one patients with HF were assessed with commonly used functional, health status, and quality of life measures, including maximal cardiopulmonary exercise testing, the Duke
more » ... Status Index (DASI), the Veterans Specific Activity Questionnaire (VSAQ), the Kansas City Cardiomyopathy Questionnaire (KCCQ), and 6-minute walk distance. Pretest clinical variables, including age, resting pulmonary function tests (forced expiratory volume in 1 s and forced vital capacity), and ejection fraction (EF) were also considered. The association between performance on these functional tools, clinical variables, and exercise test responses including peak V02 and the V02 at the ventilatory threshold, was determined. Peak oxygen uptake (VOz) was significantly related to V02 at the ventilatory threshold ( r = 0.76, P < .001) and estimated METs from treadmill speed and grade ( r = 0.72, P < .001), but had only a modest association with 6-minute walk performance ( r = 0.49, P < .01). The functional questionnaires had modest associations with peak VO2 ( r = 0.37, P < .05 and r = 0.26, NS for the VSAQ and DASI, respectively). Of the components of the KCCQ, peak V02 was significantly related only to quality of life score ( r = 0.46, P < .05). Six-minute walk performance was significantly related to KCCQ physical limitation ( r = 0.53, P < .01) and clinical summary ( r = 0.44, P < .05) scores. Among pretest variables, only age and EF were significantly related to peak V02 ( r = -0.58, and 0.46, respectively, P < .01). Multivariately, age and KCCQ quality of life score were the only significant predictors of peak VOz, accounting for 72% of the variance in peak VOz. Conclusion: Commonly used functional measures, symptom tools, and quality of life assessments for patients with HF are poorly correlated with one another and are only modestly associated with exercise test responses. These findings suggest that exercise test responses, non-exercise test estimates of physical function, and quality of life indices reflect different facets of health status in HF and one should not be considered a surrogate for another.
doi:10.1016/j.cardfail.2006.04.004 pmid:16911910 fatcat:d7qseerq7vcunik7f3twcmyhum