Utility of the Seattle Heart Failure Model for palliative care referral in advanced ambulatory heart failure

BACKGROUND: Physicians face uncertainty when predicting death in heart failure (HF) leading to underutilisation of palliative care. To facilitate decision-making, we assessed the Seattle Heart Failure Model (SHFM) as a referral tool by evaluating its performance in predicting 1-year event-free survival from death, heart transplant (HTx), and ventricular assist device (VAD) implantation. METHODS: We retrospectively reviewed the charts of consecutive patients with advanced ambulatory HF with New York Heart Association Class III/IV HF and a left ventricular ejection fraction of ≤40% from 2000 to 2016. We evaluated SHFM's performance by using the Cox proportional hazards model, its discrimination using the c-statistic, its calibration by comparing the observed and predicted survival and its clinical utility by hypothetically assessing the proportion of patients adequately or inadequately referred to palliative care. RESULTS: We included 612 patients in our study. During the 1-year follow-up, there were 83 deaths, 4 HTx and 1 VAD. Although SHFM showed very good discrimination (c-statistic=0.71) and adequate calibration in medium to low-risk patients, it underestimated event-free survival by 12% in high-risk patients. SHFM's clinical utility was limited: 33% of eligible patients would have missed the opportunity for referral and only 27% of referred patients would have benefited. CONCLUSION: Use of SHFM could result in a high proportion of referrals while capturing the majority of patients who may benefit from palliative care. Though this may be a more encompassing and safer alternative than current referral practices, it could lead to many early referrals.