Abstract 18850: Urinary 11-Dehydro-Thromboxane B2: A Novel Thrombosis Risk Marker in LVAD Recipients
Introduction: Urinary 11-dehydrothromboxane B2 (UTBx) was associated with an increased risk of thrombotic events in two major clinical trials of cardiovascular disease. The utility of UTBx as a thrombotic risk marker in patients treated with a left ventricular assist device (LVAD) is unknown.
Hypothesis: We hypothesized that UTBx is a biomarker of thrombogenicity in LVAD recipients.
Methods: At our institution 41 continuous-flow LVAD recipients (Heartmate II = 23, HeartWare HVAD = 18) had longitudinal measures of UTBx performed (n=185). UTBx testing was performed with the Aspirin works enzyme-linked immunoassay (ELISA) test. All patients were on aspirin 81mg or 325mg/daily and warfarin therapy (INR 2.0 to 2.5).
Results: In patients without bleeding and thrombotic events UTBx levels were overall numerically higher in patients on 81mg vs. 325mg aspirin, (2321 ± 1870 vs. 1839 ± 1909 pg/mg creatinine, p = 0.22); and significantly higher in patients who were not on statin therapy (2327 ± 1271 vs. 1313 ± 979, p=0.008, respectively). At two weeks after LVAD implantation UTBx rose (2119 ± 970) and returned to baseline at one-month post-LVAD implant (1331 ± 832, p = 0.002). There were marked differences in UTBx levels in patients with bleeding and thrombotic events. Prior to and at the time of thrombotic event occurrence, UTBx was higher compared to patients free of events (5660 ± 8195 and 4817 ± 4280 vs. 1587 ± 1533, respectively, p < 0.05 for both). Patients with bleeding had significantly lower UTBx than patients with thrombotic events (1318 ± 423 vs. 4817 ± 4280, p< 0.01). Serial measures of UTBx are presented in representative patients (Figure).
Conclusions: In this first report of the serial assessment of UTBx and measurement of UTBx at the time of adverse event occurrence in LVAD recipients, UTBx was associated with aspirin dose, bleeding and thrombotic events. Larger studies are warranted to validate our findings that support the utility of UTBx as a marker of risk in LVAD recipients.
Author Disclosures: P. Shah: Research Grant; Modest; Heartware, Haemonetics. K. Bliden: None. U. Tantry: None. S. Phillips: None. C. McLeod: None. M. Bradbury: None. C.O. Connor: None. P. Gurbel: Research Grant; Modest; Duke Clinical Research Institute, Haemonetics, Harvard Clinical Research Institute, Merck, NIH, New Haven Pharmaceuticals, Coramed, MedImmune, Sinnowa. Honoraria; Modest; AstraZeneca, Bayer, Boehringer Ingelheim, Daiichi Sankyo/Lilly, Haemonetics, Janssen, Merck, New Haven Pharmaceuticals. Ownership Interest; Modest; Merck. Other; Modest; Patent for platelet function testing.
- © 2016 by American Heart Association, Inc.