Cognitive impairment improves the predictive validity of physical frailty for mortality in patients with advanced heart failure referred for heart transplantation

Background The aim of this study was to identify whether the addition of cognitive impairment, depression, or both, to the assessment of physical frailty provides better outcome prediction in patients with advanced heart failure referred for heart transplantation (HT). Methods Beginning in March 2013, all patients with advanced heart failure referred to our Transplant Unit have undergone a physical frailty assessment using the Fried frailty phenotype. Cognition was assessed with the Montreal Cognitive Assessment and depression with the Depression in Medical Illness questionnaire. We assessed the value of 4 composite frailty measures: physical frailty (PF ≥ 3 of 5 = frailty), “cognitive frailty” (CogF ≥ 3 of 6 = frail), “depressive frailty” (DepF ≥ 3 of 6 = frail), and “cognitive-depressive frailty” (ComF ≥ 3 of 7 = frail) in predicting outcomes. Results Frailty was assessed in 156 patients (109 men, 47 women), aged 53 ± 13 years, and with a left ventricular ejection fraction of 27% ± 14%. Inclusion of cognitive impairment or depression in the definition of frailty increased the proportion classified as frail from 33% using PF to 42% using ComF. During follow-up, 28 patients died before ventricular assist device implantation or HT. Frailty was associated with significantly lower ventricular assist device- and HT-free survival, with CogF best capturing early mortality: 12-month survival for non-frail and frail cohorts was 81% ± 5% vs 58% ± 10% (p < 0.02) using PF and 85% ± 5% vs 56% ± 9% (p < 0.002) using CogF. Combining the Depression in Medical Illness score with PF or CogF did not strengthen the relationship between frailty and mortality. Conclusions The addition of cognitive impairment to the assessment of PF strengthened its capacity to identify advanced heart failure patients referred for HT who are at high risk of early death.