Biomarkers of Inflammation and Oxidative Stress in HeartMate II vs HeartMate 3 Patients

Purpose Inflammation and oxidative stress have been implicated in the pathophysiology of hemocompatibility related adverse events (HRAEs) in left ventricular assist device (LVAD) pts. HRAE profile differs between the continuous axial-flow HeartMate II (HMII) pump and the fully magnetically levitated centrifugal-flow HeartMate 3 (HM3). We aimed to compare levels of inflammatory and oxidative stress biomarkers in HMII vs. HM3 pts. Methods Blood was collected at three time points: n=48 pre-LVAD; n=45 3-6 mo post-LVAD, and n=56 >6 mo post-LVAD. Biomarkers of inflammation (interleukin-6 (IL6), tumor necrosis factor-α (TNFα), endothelin-1 (ET1) and adiponectin (A)) and oxidative stress (isoprostane (I)) were measured using standard techniques. Wilcoxon and Kruskal Wallis tests were performed to assess differences in biomarker levels between pumps and among time points, respectively. Linear models adjusted by age, sex and time on support were created to assess differences in biomarker levels between HMII and HM3 at 3-6 mo and >6 mo post-LVAD. Results 89 LVAD pts (age 57±14 y, 83% M, 42 (47.2%) HM3 and 47 (52.8%) HMII) were studied. Overall trends of biomarkers levels are shown in Table 1. Circulating levels of all biomarkers of inflammatory and oxidative stress were significantly lower at 3-6 mo and >6-mo compared to pre-implant levels, albeit higher than the reference values. In adjusted models: i) IL6 and TNFα levels were higher in HM3 pts at 3-6 mo (p=0.02 and p=0.04, respectively) but not at >6 mo compared to HMII pts; and ii) levels of all other biomarkers did not differ between HMII and HM3 pts. Conclusion During long-term support (>6 mo), circulating biomarkers of inflammation and oxidative stress are similarly lower in HMII and HM3 pts compared to pre-implant levels. More studies are warranted to assess the impact of residual inflammatory and oxidative burden on HRAEs in this unique population.