Abstract Body (Do not enter title and authors here): Background: Adolescents with cardiac implantable electronic devices (CIEDs) face greater psychological distress than their peers. Fluctuations over time and mitigating factors remain unclear.

Objectives: We assessed the mental health symptom burden among adolescents with CIEDs over time, measured its impact on health-related quality of life (QoL) and executive functioning (ExF), and identified factors associated with mental health distress.

Methods: In a single center, prospective study from 1/2023 – 5/2024, 41 CIED patients, median 18 years (range 12-21) completed serial validated mental health measures of anxiety, depression, post-traumatic stress disorder (PTSD), cardiac QoL, and ExF. Primary outcome: abnormal mental health screen in any of the domains. Secondary outcome: clinically significant change in anxiety or depression scores, defined as ≥6 and ≥5, between baseline and 3-month follow-up. Univariable linear regression model assessed association between QoL score and select variables.

Results: Fifty-four percent of patients had abnormal baseline mental health screens (39% poor cardiac QoL, 36% trauma history, 28% anxiety, 17% depression, 13% abnormal ExF, 5% PTSD). At follow-up, 34% of anxiety or depression scores were clinically significant (Figure). Higher anxiety and depression scores, male sex, and higher PTSD scores were associated with lower cardiac QoL (coefficients: -2.00, p<0.001; -2.23, p<0.001; -10.53, p=0.007; and -0.75, p=0.002). Higher resilience score correlated with increased overall QoL (coefficient: 1.06, p=0.004) but not cardiac QoL (coefficient: 0.54, p=0.11). Mental health scores were not associated with cardiac diagnosis, CIED type or date of implant, or number of ICD shocks.

Conclusion: Over 50% of adolescents with CIEDs had abnormal mental health screens. Anxiety and depression scores fluctuated significantly over 3 months. Higher baseline anxiety, depression, and PTSD scores and male sex were linked to lower cardiac QoL. Higher resilience improved overall QoL. Mental health measures showed no association with cardiac diagnosis type, CIED type or duration, or ICD shocks. Routine mental health screening is crucial for improving mental health and quality of life in this population.