Year of Publication

2019

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Nursing

Department

Nursing

First Advisor

Dr. Debra Moser

Abstract

Heart failure is a progressive condition that affects over 5.7 million Americans and costs associated with heart failure account for 2-3 % of the national health care budget. The high rates of morbidity and mortality along with increased costs from readmissions associated with advanced heart failure have led to the exploration of advanced treatments such as left ventricular assist devices (LVADs). LVADS have demonstrated morbidity and mortality benefit but cost remains extensive with costs per quality-adjusted years > $400,000. With this in mind, it is important to identify those who are most likely to benefit from an LVAD to avoid unfavorable outcomes and cost. Although general guidelines and criteria for patient eligibility have been established, choosing patients for LVAD implantation remains challenging. A new focus on patient selection involves the presence of frailty. While frailty has been studied in the elderly population and in patients undergoing cardiac surgery, frailty in patients undergoing left ventricular assist device (LVAD) remains controversial. The purpose of this dissertation was to examine measures of frailty in patients undergoing LVAD implantation. The specific aims of this dissertation were to: (1) identify a feasible frailty measure in adults with end-stage heart failure who underwent LVAD implantation by testing the hypothesis that frailty would predict 30 day rehospitalization rates using Fried’s criteria, Short Physical Performance Battery test, handgrip strength, serum albumin and six minute walk test (2) Determine whether frailty measures improve 3 months post LVAD implantation (3) compare sensitivity of these three measures to change in frailty.

Surgical approaches, including heart transplantation and LVAD implantation, for patients with end-stage heart failure was discussed in this dissertation. Data from two subsets of participants who underwent LVADS at the University of Kentucky between 2014 and 2017 were included in the analysis for this dissertation. In the first study, we found that none of the measures are good predictors of frailty in patients with advanced heart failure who undergo LVAD implantation. Handgrip was the only marker of frailty that predicted 30 day readmission but the relationship was a negative association. In the second study, six-minute walk and low serum albumin levels reflect short-term improvement in frailty. These simple measures may be used to determine those patients who are responsive to LVAD implantation.

The findings of these studies filled some gaps in our understanding of markers of frailty in patients undergoing LVADs. We gained a better understanding of which markers of frailty are likely to improve in most people after LVAD implantation and thus frailty should not preclude candidate selection for an LVAD. Subsequently, more research is needed to investigate these markers and outcomes.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2019.373

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