Predicting Survival in Patients Receiving Continuous Flow Left Ventricular Assist Devices: The HeartMate II Risk Score

The aim of this study was to derive and validate a model to predict survival in candidates for HeartMate II (HMII) (Thoratec, Pleasanton, California) left ventricular assist device (LVAD) support. LVAD mortality risk prediction is important for candidate selection and communicating expectations to patients and clinicians. With the evolution of LVAD support, prior risk prediction models have become less valid. Patients enrolled into the HMII bridge to transplantation and destination therapy trials (N = 1,122) were randomly divided into derivation (DC) (n = 583) and validation cohorts (VC) (n = 539). Pre-operative candidate predictors of 90-day mortality were examined in the DC with logistic regression, from which the HMII Risk Score (HMRS) was derived. The HMRS was then applied to the VC. There were 149 (13%) deaths within 90 days. In the DC, mortality (n = 80) was higher in older patients (odds ratio [OR]: 1.3, 95% confidence interval [CI]: 1.1 to 1.7 per 10 years), those with greater hypoalbuminemia (OR: 0.49, 95% CI: 0.31 to 0.76 per mg/dl of albumin), renal dysfunction (OR: 2.1, 95% CI: 1.4 to 3.2 per mg/dl creatinine), coagulopathy (OR: 3.1, 95% CI: 1.7 to 5.8 per international normalized ratio unit), and in those receiving LVAD support at less experienced centers (OR: 2.2, 95% CI: 1.2 to 4.4 for