Publication Date

2023

Document Type

Dissertation/Thesis

First Advisor

Mazurek, Kathryn

Degree Name

Ph.D. (Doctor of Philosophy)

Legacy Department

School of Interdisciplinary Health Professions

Abstract

The prevalence of heart failure is on the rise, with projections indicating that nearly 3% of the American population will be affected by 2030. This condition is particularly prevalent in adults, with a disproportionate impact on minority communities. The US population is aging, and the lifetime risk of heart failure increases with age. Patients with Stage D heart failure may need advanced surgical therapies, such as a heart transplantation (HT) or long-term mechanical circulatory support (MCS), if ineligible for HT. Health-related quality of life (HRQOL) may differ by race in patients who undergo these advanced surgical therapies. While there have been improvements in the treatment of heart failure, patients continue to experience frequent hospitalization, increased symptom burden, and poor HRQOL.In the first study, a systematic review was conducted to examine the relationship between race and HRQOL outcomes of older patients with advanced heart failure who received surgical therapies (long-term MCS or HT). The search strategy utilized combined keywords and Medical Subject Headings (MeSH): Describing older adults, MCS, HT, US racial and ethnic minorities as identified by the American Community Survey 1-Year Estimates Data Profiles. The search was applied to Medline (Ovid), The Cochrane Library (Wiley), Scopus (Elsevier), CINAHL Plus with Full Text (EBSCOhost), and PsycInfo (EBSCOhost) on July 14, 2021. ClinicalTrials.gov was also searched for additional studies. The systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) under the ID-CRD42021266728. A total of 2,319 records were identified, of which, seven studies met the inclusion criteria, and all studies were graded as having a low risk of bias. On average, study participants were middle-aged to older (mean age 56 years), and most were male (81%) and the majority were White (77%). Race did not impact overall HRQOL scores and domains in 50% of HT studies. All patients with MCS showed improvement in overall HRQOL and domains from 1 month to 1 year post-implantation. Yet, compared to White patients, African American patients experienced less improvement in HRQOL over time. In the second study, the change in HRQOL by race in older patients with heart failure, from before to after HT or long-term MCS, was examined. The aim of this study was to determine whether older advanced patients with heart failure who undergo long-term MCS, as compared to patients who undergo HT (with or without MCS prior to surgery), experience non inferior change in overall HRQOL (primary endpoint, using the KCCQ-12 overall summary score [OSS]) by race (White vs. all minorities), longitudinally from baseline to 1 year post operatively. There were 396 enrollees, and, of these, 305 patients underwent surgery: n = 144 long-term MCS patients, n = 68 HT patients with MCS prior to surgery (heart transplant non-bridge to transplant; HT BTT), and 93 HT patients without MCS prior to surgery (heart transplant non-bridge to transplant; HT Non-BTT). The average age of the entire group was 66.2 ± 4.7 years, with the long-term MCS participants being older. Overall, participants were mostly male (n = 238, 78%) and mostly White (n = 254, 84%) and tended to have more than a high school education (n = 273, 78%), and nearly 80% (n = 237) were married/partnered. Based on the NI test, the White long-term MCS group did not demonstrate non-inferiority (NI) compared to the White HT BTT and White HT Non-BTT groups. This determination was made based on the upper confidence limits (long-term MCS vs. HT BTT: −23.86, −13.19; long-term MCS vs. HT Non-BTT: −25.15, −15.85), which did not meet the NI margin of −5. Thus, it can be concluded that HT is superior to long-term MCS in terms of HRQOL in White patients. Furthermore, the long-term MCS minority group was also found to be non-inferior when compared to both the HT BTT minority group and HT Non-BTT minority group. This conclusion was reached after a thorough analysis of the upper confidence limits, which demonstrated a difference of −30.04 to −3.97 between long-term MCS and HT BTT and −27.95 to 0.70 between long-term MCS and HT Non-BTT. It is important to note that the wide range observed in the confidence intervals may be due to the limited number of participants in the minority group. In Study 3, the association of race with HRQOL in older patients after HT or long term MCS was investigated. The aim of the study was to determine whether race is a risk factor associated with overall HRQOL (using the KCCQ-12 OSS), for older patients (60–80 years old) who undergo long-term MCS or HT “at 1 year post-operatively.” To investigate whether race was a risk factor for poor HRQOL, multivariable linear mixed models analyses were carried out using the KCCQ-12 OSS as the dependent variable 1 year after surgery. The results showed that White participants had a higher KCCQ-12 OSS score (5.62 points), but this difference was not statistically significant (p-value = 0.11) after controlling for other variables. Although White participants (long-term MCS group) had a higher average KCCQ-12 OSS score than minority participants, the association of race with overall HRQOL was not statistically significant. Interestingly, other variables were found to be significantly associated with a higher HRQOL, including surgery strategy (HT BTT and HT Non-BTT) and sex (male). Conversely, factors such as a higher New York Heart Association (NYHA) class and post-operative adverse events (AEs) were associated with lower overall HRQOL. The findings of this dissertation showed that patients experienced an improvement in HRQOL outcomes from before to after surgery, regardless of their race. However, the study also revealed that minorities and women tend to experience a relatively smaller gain in HRQOL as compared to Whites, even though all patients in the study showed improvement. This underscores the importance of conducting further research to investigate HRQOL differences across various racial groups, as it can inform shared decision-making regarding advanced surgical treatment options and guide HRQOL-related therapies.

Extent

156 pages

Language

en

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

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