Health-related quality of life in relation to different levels of disease severity in patients with chronic heart failure.

The purpose of the present study was to compare differences in physiological outcomes and health-related quality of life (HRQOL) in relation to degree of illness in patients with chronic heart failure (CHF) and to compare HRQOL in CHF patients with that of a normal Japanese population. One hundred and twenty-five patients with stable CHF (93 men, 32 women, mean age 63.3 ± 12.4 years) with left ventricular ejection fraction (LVEF) of less than 40% were enrolled in the present study. We used New York Heart Association (NYHA) functional class as an index of degree of illness. In 64 of the 125 patients, physiological outcome measures included peak oxygen uptake (peak O2) and E/CO2 slope. HRQOL was assessed with the medical outcome study short form-36 (SF-36) Japanese version. In addition, SF-36 scores of CHF patients were compared against Japanese standard values. Age and LVEF did not differ according to NYHA functional class. The eight SF-36 subscale scores and peak O2 decreased with increases in the NYHA functional classes, whereas E/CO2 slope increased with increases in NYHA functional class (p<0.05). Of the 8 SF-36 subscales measured in CHF patients, only the bodily pain score attained that of the normal Japanese population. These findings suggest that HRQOL decreases as NYHA functional class increases and other physiological measures worsen. In addition, HRQOL values of CHF patients were low in comparison with standard values of a normal Japanese population.