Abstract 18412: Lactate Dehydrogenase Trends Predict Left Ventricular Assist Device Thrombosis
Introduction: Recent analyses have demonstrated an increasing risk of HeartMate II (HMII) left ventricular assist device (LVAD) thrombosis than previously reported. Elevation of serum lactate dehydrogenase (LDH), a biomarker of hemolysis secondary to thrombosis, parallels the overall pattern of HMII thrombosis.
Hypotheses: We hypothesized that longitudinal trends of LDH could predict HMII thrombosis.
Methods: From 10/2004 through 9/2014, 350 HMII devices were implanted in 323 patients at a single center. Of these, patients on 339 devices had at least 1 postop LDH value through 9/2014 (7,996 total measurements). A 2-step joint model combining longitudinal biomarker data and pump thrombosis events was generated to assess the impact of changing LDH on the risk of thrombosis. Device-specific LDH values were first estimated using Multivariate Boosted Trees to reduce measurement error and produce unbiased regression estimates. Estimated LDH values were then used as a time-varying covariate function in a multiphase hazard model to analyze time to thrombosis.
Results: Thirty-five HMII pumps (10%) had either confirmed (18 HMIIs) or suspected (17 HMIIs) thrombosis, with 15 (43%) occurring within 3 months of implant. LDH was associated with pump thrombosis occurring both early and late after implant (P<.0001 for both phases). The model demonstrated increased probability of HMII thrombosis as LDH trended upward, with steep changes in thrombosis probability paralleling similar trajectories in LDH. Two individual patient probaliities are graphed in the figure.
Conclusions: Longitudinal trends in surveillance LDH for patients on HMII support is useful for dynamic prediction of pump thrombosis, both early after implant and late. Incorporating upward and downward trends in LDH provides a dynamically updated model of LVAD thrombosis risk that may eventually be a tool for LVAD clinical management.
Author Disclosures: T. Hurst: None. J. Ehrlinger: None. J. Rajeswaran: None. L. Thuita: None. N. Smedira: None. N. Moazami: None. E. Blackstone: None. R.C. Starling: None.
- © 2015 by American Heart Association, Inc.