Characterizing sleep health, sleep disorders, and cognitive functioning after heart transplantation

The National Institutes of Health National Heart Lung and Blood Institute awarded Mayo Clinic Arizona $243,678 on December 21, 2025, under the Cardiovascular Diseases Research program (CFDA 93.837) to conduct a multisite longitudinal study characterizing sleep health, sleep disorders, and cognitive functioning in heart transplant recipients.

The study will enroll 30 adult heart transplant recipients who are at least six months post-transplant and obtain repeated measures at nine and twelve months post-transplant. The research will describe sleep health characteristics (regularity, satisfaction, alertness/sleepiness, timing, efficiency, and duration), sleep disorders (obstructive sleep apnea, insomnia, restless legs syndrome), and cognitive function (executive function, attention, episodic memory, working memory, processing speed, language) at six months post-transplant, then characterize changes in these variables at nine and twelve months after transplant surgery. The study will identify which sleep health characteristics and sleep disorders predict cognitive function in heart transplant recipients.

The work addresses a documented gap: cognitive impairment affects 30 to 63 percent of heart transplant recipients and limits their ability to self-manage complex post-transplant medical regimens, yet the relationship between sleep health and cognitive functioning after heart transplantation has not been examined.

Performance occurs in Scottsdale, Arizona, with an ultimate completion date of July 1, 2027. The award is structured as a project grant, a standard assistance type under the NHLBI program.

Abstract

Cognitive impairment impacts 30-63% of the people who receive a heart transplant. Cognitive impairment limits their ability to self-manage the necessary and complex medical regimens required to maintain viability of the transplanted heart and is associated with worse post-transplant survival. Sleep health may represent a modifiable factor that contributes to cognitive impairment after heart transplantation; however, the relationship between sleep health and cognitive functioning after heart transplantation has not been examined. The paucity of comprehensive sleep health research in this population prevents the development of precision sleep health interventions. Additionally, sleep disorders, including insomnia and obstructive sleep apnea, are associated with impaired cognitive functioning in other complex conditions, but these relationships have not been explored after heart transplantation. To address these scientific gaps, a multisite, longitudinal study will be conducted to obtain a comprehensive evaluation of sleep health, sleep disorders, and cognitive functioning in heart transplant recipients. We will enroll 30 adult heart transplant recipients who are at least 6 months post- transplant. Repeated measures will be obtained at 9- and 12-months post-transplant. We will: (1) describe sleep health characteristics (regularity, satisfaction, alertness/sleepiness, timing, efficiency, duration), sleep disorders (obstructive sleep apnea, insomnia, restless legs syndrome), and cognitive function (executive function, attention, episodic memory, working memory, processing speed, language) in heart transplant recipients at 6 months post-transplant, and characterize changes among these variables at 9 months and 12 months after the transplant surgery; (2) identify which sleep health characteristics (regularity, satisfaction, alertness/sleepiness, timing, efficiency, duration) and sleep disorders (obstructive sleep apnea, insomnia, restless legs syndrome) are associated with cognitive function at 6 months, 9 months, and 12 months after heart transplantation. Training on sleep health, sleep disorders, cardiovascular outcomes, cognitive assessments, statistical analyses, scientific writing, and intervention development, will provide the applicant with the skills and knowledge necessary to conduct this research and to launch an independent research career. The foundational data obtained from this research study, will critically inform the development of precision sleep health interventions designed to promote optimal cognitive functioning for heart transplant recipients as they navigate complex medical regimens.