Abstract Body (Do not enter title and authors here): Introduction: Heart failure (HF) impacts quality of life considerably, with inflammatory biomarkers potentially playing a significant role in this relationship. The purpose of this study is to examine the relationship between NYHA Class, inflammatory biomarkers, and quality of life in Black adults living with HF.

Methods: Black adults living with HF (N=41) were enrolled in this study. NYHA Class was extracted from the medical record. Health-related quality of life was measured using the Kansas City Cardiomyopathy Questionnaire (KCCQ), a 23-item questionnaire that quantifies physical function, symptoms, social function, and health-related quality of life in HF. Scores are transformed to a range of 0-100, with higher scores reflecting better health status. One-way ANOVA and correlation analyses were used to assess associations between NYHA class, inflammatory biomarkers (XO activity, IL-1β, IL-15, and CCL-19), and KCCQ scores.

Results: Participants were 57±11 years of age and 66% female, with mean LVEF 33±14%. NYHA Class ranged from I (20%) to IV (12%), with the majority of participants in Class II (34%) and III (22%). Mean KCCQ Clinical Summary Score was 85± 21. NYHA Class I had significantly lower scores on the KCCQ Clinical Summary Score compared to Class III and IV (p < .001, η² = 0.54), KCCQ Physical Limitation compared to Class II, III, and IV (p < .001, η² = 0.53), and KCCQ Symptom Frequency compared to Class IV (p = .001, η² = 0.39). The KCCQ Clinical Summary Score was negatively associated with XO activity (r = -0.440, p = .046), IL-1β (r = -0.407, p = .043), IL-15 (r = -0.427, p = .033), and CCL-19 (r = -0.559, p = .004). Similar negative associations were observed for the KCCQ subscales.

Conclusion: The negative association between XO activity and health-related quality of life (KCCQ) in individuals with HF highlights the potential impact of oxidative stress on these patients' subjective well-being and functional status. Understanding this relationship could underscore the importance of mitigating oxidative stress pathways to improve the overall quality of life and symptom burden experienced by individuals with HF. The KCCQ and subscales were also negatively associated with markers of inflammation, highlighting the potential impact of systemic inflammatory processes on subjective well-being and functional status in persons with HF. Targeting inflammatory pathways may improve quality of life and mitigate the burden of symptoms in HF.