The Circulation article describes its development. It used data from 6 cohorts of patients (outpatients with mostly left-sided systolic heart failure), which was gathered in other controlled trials; they used multivariate analyses to derive the prediction model using one trial (n=1100), then validated it using the patient data from the 5 other trials (n=10,000). Of note they mention that the biggest univariate predictor of death was diuretic use (in milligrams of furosemide equivalents per kilogram of body mass). These are graphs from both the derivation and validation cohorts (predicted vs. actual mortality), showing generally very tight fits.
(Click to see full size.)I'm not really qualified to judge the validity of this, but I'm curious to see how it is going to be used. Its feature letting you "see" the mortality benefit from adding in a device is curious, and open to misinterpretation it seems. Its use in the palliative world, obviously, would be to identify those patients at particularly high risk of death and thus "in need" of palliative-oriented services--but what this model adds over usual clinical assessment is unclear as of now. Also, this used data from controlled trials which generally have highly select patient groups in them--not necessarily healthy patients (many involved NYHA Class 3 & 4 patients)--but perhaps ones with fewer comorbidities etc (I have not looked at the in-/exclusion criteria for these trials of course). A prospective multicenter validation would be nice. Also, when looking at the graphs, one gets the impression that most of the subjects in these trials had estimated and actual survivals well over 1 year, which makes me wonder how accurate this will be for the sickest patients with the potentially shortest estimated survivals...