Abstract 18940: Application of the HeartMateII Risk Score in Patients With Continuous Flow Left Ventricular Assist Devices
Background: Survival with left ventricular assist device (LVAD) therapy is dependent on appropriate patient selection. The Heart Mate II Risk Score (HMRS) was recently derived and validated in clinical trial patients to predict 90 day mortality following implantation of a continuous flow LVAD. The aim of this study was to test the validity of the HMRS in our patient population.
Methods: We performed a retrospective analysis of patients implanted with HeartMate II (Thoratec, Pleasanton, CA) LVADs from March 31, 2004 to September 20, 2012. Patients were stratified according to HMRS profiles (HMRS Low < 1.58; < 1.58 HMRS Medium < 2.48; HMRS High > 2.48) calculated using age, albumin, creatinine, international normalized ratio (INR) and center volume. Outcome was defined as survival at 90 days post-device implantation.
Results: HeartMate II LVADs were implanted in 205 patients. Pre-operative data from 201 patients were categorized into HMRS Low (n=101; 1.04 (0.64-1.31)), HMRS Medium (n=73; 1.98 (1.78-2.25)), and HMRS High (n=27, 3.07 (2.70-3.43)); p<0.0001. Kaplan Meier survival estimates at 90 days (HMRS Low 91.0 ± 2.9%; HMRS Medium 91.7 ± 3.2 %; HMRS High 88.7 ± 6.1%), and at one year (HMRS Low 85.5 ± 3.8%; HMRS Medium 79.3 ± 5.5%; HMRS High 82.4 ± 8.4%) following LVAD implantation were not statistically different, p=0.43, Figure. HMRS discrimination to predict 90 day mortality by receiver characteristic curve analysis was poor, AUC=0.56.
Conclusion: The HMRS successfully stratifies patients according to pre-operative clinical characteristics. In our HeartMate II LVAD population, the HMRS demonstrated poor discrimination for 90 day mortality. HMRS generalizability may be limited.
- © 2013 by American Heart Association, Inc.