Associations of body mass index and hospital-acquired disability with post-discharge mortality in older patients with acute heart failure

OBJECTIVES To investigate the effect of hospital-acquired disability(HAD) on all-cause mortality after discharge according to the body mass index(BMI) in older patients with acute decompensated heart failure.METHODS We included 408 patients aged ≥ 65 years who were hospitalized for acute decompensated heart failure and had undergone an acute phase of cardiac rehabilitation at the Sakakibara Heart Institute between April 2013 and September 2015(median age: 82 years, interquartile range(IQR): 76–86; 52% male). Patients were divided into three groups based on BMI at hospital admission: underweight(< 18.5 kg/m2), normal weight(18.5 to 25 kg/m2), and overweight(≥ 25 kg/m2). HAD was defined as a decrease of at least five points at discharge compared to before hospitalization according to the Barthel Index.RESULTS The median follow-up period was 475(IQR: 292–730) days, and all-cause mortality during the follow-up period was84 deaths(21%). According to multivariate Cox regression analysis, being underweight(HR: 1.941, 95% CI: 1.134-3.321, P = 0.016)or overweight(HR: 0.371, 95% CI: 0.171-0.803, P = 0.012), with normal BMI as the reference, and HAD(HR: 1.857, 95% CI:1.062-3.250, P = 0.030) were independently associated with all-cause mortality. Patients with HAD exhibited a significantly lower cumulative survival rate in the underweight group(P = 0.001) and tended to have a lower cumulative survival rate in the normal weight group(P = 0.072). HAD was not significantly associated with cumulative survival in the overweight group(P = 0.392).CONCLUSIONS BMI and HAD independently predicted all-cause mortality after discharge in older patients with acute decompensated heart failure. Furthermore, HAD was significantly associated with higher all-cause mortality after discharge, especially in the underweight group.