Keywords

[beta]-adrenergic receptor kinase-1, health-related quality of life, left ventricular assist device, norepinephrine, sympathetic nervous system

 

Authors

  1. Denfeld, Quin E. PhD, RN
  2. Lee, Christopher S. PhD, RN, FAAN, FAHA, FHFSA
  3. Woodward, William R. PhD
  4. Hiatt, Shirin O. MS, RN, MPH
  5. Mudd, James O. MD
  6. Habecker, Beth A. PhD

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 ([beta]-adrenergic receptor kinase-1 [[beta]ARK1], 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 [beta]ARK1 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 [beta]ARK1 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 [beta]ARK1 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.