People recovering from heart failure may significantly improve their chances of avoiding further complications by maintaining a regular sleep routine, according to a new study led by Oregon Health & Science University (OHSU). Published in JACC Advances, the research highlights the risks associated with irregular sleep schedules, showing that even moderate inconsistency can double the likelihood of a serious medical event within six months. Such events could range from emergency room visits and hospital readmissions to fatalities.
The investigation was conducted by a team of OHSU researchers, led by Brooke Shafer, Ph.D., a research assistant professor in the Sleep, Chronobiology and Health Laboratory within the OHSU School of Nursing. Shafer underscored the broader health implications of sleep consistency, but stressed its particular importance for those already managing heart failure. “Going to bed and waking up at consistent times is important for overall health,” she explained. “Our study suggests that consistency in sleep timing may be essential for adults with heart failure.”
Between September 2022 and October 2023, the team enrolled 32 patients who had been admitted to OHSU Hospital and Hillsboro Medical Centre for acutely decompensated heart failure. After discharge, participants kept detailed sleep diaries for one week, recording when they went to sleep, woke up, and whether they took naps during the day. This data enabled the researchers to categorise individuals as either “regular” or “moderately irregular” sleepers, depending on the stability of their patterns.
The results were striking. Over the following six months, 21 participants experienced another clinical event. Among them, 13 were classified as moderately irregular sleepers, while only eight were identified as having regular sleep habits. Statistically, the irregular group faced more than double the risk of recurrence compared with their counterparts who maintained consistency. Importantly, this elevated risk persisted even after researchers adjusted for potential confounders such as other sleep disorders and chronic health conditions.
According to the authors, this is one of the first studies to specifically assess the impact of sleep regularity on heart failure outcomes. The findings contribute to a growing body of research suggesting that the timing of sleep—alongside its quality and duration—plays a key role in cardiovascular health. The team concluded that encouraging patients to stabilise their sleep schedules could provide a low-cost, non-invasive way to reduce the likelihood of repeat medical crises among those recovering from heart failure.
Shafer added that the physiological mechanisms behind this link may involve the cardiovascular system’s natural rhythm. “When we’re asleep and in a resting state, our blood pressure and heart rate decrease compared with daytime levels,” she said. “But variability in sleep timing may disrupt mechanisms involved in the regulation of the cardiovascular system. Irregular sleep may contribute to adverse outcomes, especially for people already affected by heart failure.” Moving forward, the researchers plan to scale up their study with a larger cohort to explore whether interventions that directly improve sleep regularity can further reduce risks in this vulnerable population.
More information: Brooke Shafer et al, Effect of Posthospitalization Sleep Regularity on Clinical Events in Adults With Heart Failure, JACC Advances. DOI: 10.1016/j.jacadv.2025.102109
Journal information: JACC Advances Provided by Oregon Health & Science University
