Sympathetic Markers are Different Between Clinical Responders and Nonresponders After Left Ventricular Assist Device Implantation Denfeld, Quin E. PhD, RN; Lee, Christopher S. PhD, RN, FAAN, FAHA, FHFSA; Woodward, William R. PhD; Hiatt, Shirin O. MS, RN, MPH; Mudd, James O. MD; Habecker, Beth A. PhD The Journal of Cardiovascular Nursing: 7/8 2019 - Volume 34 - Issue 4 - p E1-E10 doi: 10.1097/JCN.0000000000000580 https://journals.lww.com/jcnjournal/pages/articleviewer.aspx?year=2019&issue=07000&article=00011&type=Fulltext Abstract Background Clinical response to left ventricular assist devices (LVADs), as measured by health-related quality of life, varies among patients after implantation; however, it is unknown which pathophysiological mechanisms underlie differences in clinical response by health-related quality of life. Objective The purpose of this study was to compare changes in sympathetic markers (β-adrenergic receptor kinase-1 [βARK1], norepinephrine [NE], and 3,4-dihydroxyphenylglycol [DHPG]) between health-related quality of life clinical responders and nonresponders from pre– to post–LVAD implantation. Methods We performed a secondary analysis on a subset of data from a cohort study of patients from pre– to 1, 3, and 6 months after LVAD implantation. Clinical response was defined as an increase of 5 points or higher on the Kansas City Cardiomyopathy Questionnaire Clinical Summary score from pre– to 6 months post–LVAD implantation. We measured plasma βARK1 level with an enzyme-linked immunosorbent assay and plasma NE and DHPG levels with high-performance liquid chromatography with electrochemical detection. Latent growth curve modeling was used to compare the trajectories of markers between groups. Results The mean (SD) age of the sample (n = 39) was 52.9 (13.2) years, and most were male (74.4%) and received LVADs as bridge to transplantation (69.2%). Preimplantation plasma βARK1 levels were significantly higher in clinical responders (n = 19) than in nonresponders (n = 20) (P = .001), but change was similar after LVAD (P = .235). Preimplantation plasma DHPG levels were significantly lower in clinical responders than in nonresponders (P = .002), but the change was similar after LVAD (P = .881). There were no significant differences in plasma NE levels. Conclusions Preimplantation βARK1 and DHPG levels are differentiating factors between health-related quality of life clinical responders and nonresponders to LVAD, potentially signaling differing levels of sympathetic stimulation underlying clinical response.