High Sedentary Time After ACS Doubles Risk of Cardiac Events, but Cutting It May Lower Mortality: Study

The study evaluated 609 patients admitted to a New York City emergency department with symptoms indicative of ACS between 2016 and 2020. Participants, with an average age of 62 years and predominantly Hispanic (58%), wore wrist-mounted accelerometers for 30 days after discharge to objectively monitor their activity levels, including sleep, light activity, moderate-to-vigorous activity, and sedentary time.

The study led to the following findings:

• During the one-year follow-up, 8.2% of participants experienced a major cardiac event or died.
• The average sedentary time recorded among participants was 13.6 hours per day.
• Individuals with the highest levels of sedentary behavior (more than 13.6 hours/day) had a 2.5 times greater risk of cardiac events or death compared to those with the least sedentary time.
• A statistically significant trend confirmed the harmful impact of prolonged inactivity on cardiac recovery.
• Replacing 30 minutes of sedentary time with sleep was associated with a 14% reduction in the risk of cardiac events or mortality (HR: 0.86).
• Substituting the same amount of sedentary time with light-intensity physical activity resulted in a 51% lower risk (HR: 0.49).
• Engaging in moderate-to-vigorous physical activity in place of 30 minutes of sedentary time provided the most benefit, reducing risk by 61% (HR: 0.39).

"These results shed light on an often-overlooked factor in post-ACS recovery—sedentary behavior," the authors noted. "Encouraging even small shifts away from inactivity may have a meaningful impact on long-term outcomes."

The study emphasizes the importance of post-discharge rehabilitation strategies that go beyond medication and include behavioral modifications to increase physical activity. As many patients recovering from ACS may not be able to engage in vigorous exercise immediately, the data suggest that even substituting sedentary time with light movement or adequate sleep could yield substantial health benefits.

Given the high rate of adverse outcomes following hospitalization for ACS symptoms, the researchers call for greater attention to sedentary time as a modifiable risk factor. Tailored interventions to reduce sitting time and promote active recovery may offer a practical and impactful approach to improving patient prognosis in the critical months following discharge.

"These findings suggest that minimizing sedentary behavior could be an effective approach to enhance recovery and reduce risks following hospital discharge," the researchers concluded.

Reference:

Diaz KM, Boudreaux BD, Xu C, Sanchez GJ, Murdock ME, Cruz GJ, Jurado A, Gonzalez A, Chang MJ, Scott A, Lee SAJ, Romero EK, Sullivan AM, Duran AT, Schwartz JE, Kronish IM, Edmondson D. Sedentary Behavior and Cardiac Events and Mortality After Hospitalization for Acute Coronary Syndrome Symptoms: A Prospective Study. Circ Cardiovasc Qual Outcomes. 2025 May 19:e011644. doi: 10.1161/CIRCOUTCOMES.124.011644. Epub ahead of print. PMID: 40384460.