Many people who've been treated for chest pain are particularly prone to spend most of their days sitting, reclining, or lying down after they've been discharged from the hospital.
But that's a high-risk behavior, a new study from researchers at Columbia University Vagelos College of Physicians and Surgeons has found.
The study found that patients who racked up more than 15 hours of daily sedentary behavior on average were twice as likely to experience more heart trouble or die in the year after discharge than patients who accrued a daily average of 12 hours of sedentary time."One doesn't have to start running marathons after a cardiovascular event to see benefits. Sitting less and moving or sleeping a little more can make a real difference."
Replacing just 30 minutes of sedentary time with more activity-or sleep-may reduce the risks substantially, the researchers also found.
"What we're learning is that one doesn't have to start running marathons after a cardiovascular event to see benefits. Sitting less and moving or sleeping a little more can make a real difference," says study leader Keith Diaz, the Florence Irving Associate Professor of Behavioral Medicine, who is an expert on sedentary behavior and heart disease.
Millions hospitalized each year with chest pain
Over 7 million people in the U.S. are admitted to the hospital with chest pain suggestive of acute coronary syndrome, which reduces blood flow to the heart and sometimes leads to a heart attack.
Keith Diaz
Sedentary time-defined as any awake activity that involves little to no physical movement-has been linked to poor heart health, heart attacks, and other cardiac events in the general population. But evidence for a link among people who have been hospitalized for acute coronary syndrome is surprisingly sparse.
Patients with acute coronary syndrome are sedentary for 12 to 13 hours a day after hospitalization. They remain at high risk for cardiac events and death even with optimal medical treatment.
The risk also remains high for patients with chest pain who are discharged without a diagnosis of acute coronary syndrome. "Even though they're not diagnosed during their stay, we're starting to realize that these patients do not have benign conditions," Diaz says.
Guidelines recommend that ACS patients exercise regularly but there is little mention of sedentary behavior as a risk factor to be modified.
"We know very little about how to reduce the risk across the full spectrum of people hospitalized for chest pain and other symptoms of acute coronary syndrome," Diaz adds.
What the study found
Participants with the greatest sedentary time (averaging more than 15 hours a day) were 2.5 times more likely to experience a cardiac event or die in the following year than participants with the least sedentary time (averaging just under 12 hours a day).
- Prolonged, uninterrupted sedentary bouts were associated with an increased risk of 1-year cardiac events and mortality.
- The combination of large amounts and longer bouts of sedentary time was associated with the highest risk for 1-year cardiac events/mortality.
- Modeling showed that replacing 30 minutes of sedentary behavior with light-intensity physical activity each day may reduce the risk of another cardiovascular event or death by 50%; and replacing 30 minutes of sedentary time with 30 minutes of moderate to vigorous physical activity each day may reduce the risk by 61%.
Modeling also suggests that replacing 30 minutes of sedentary time with 30 minutes of sleep lowers heart risk by 14%. "We were surprised that replacing sedentary time with sleep also lowered risk because the health harms of sedentary time are thought to be linked to muscle inactivity," Diaz says, and sleep does not involve movement or engage muscles and occurs in the same posture as some sedentary time.
"For patients who don't have the ability, desire, or resources to be more physically active, this finding is encouraging news," he adds. "Something as simple as getting a bit more sleep, rather than watching one more episode on Netflix, can make a difference in recovery."
"Something as simple as getting a bit more sleep, rather than watching one more episode on Netflix, can make a difference in recovery."
Next steps
While the new study highlights the risks of prolonged sitting after a heart event, it was an observational study and clinical trials are needed.
"Current guidelines for adults to reduce the health harms of sitting lack specific, actionable recommendations and instead rely on vague instructions to 'sit less, move more,'" Diaz says. "Our next steps are to conduct clinical trials to determine how often and for how long to move throughout the day to offset the harms of sitting after a heart event."
References
More information
The study, "Sedentary Behavior and Cardiac Events and Mortality After Hospitalization for Acute Coronary Syndrome Symptoms: A Prospective Study," was published May 19 in Circulation: Cardiovascular Quality and Outcomes.
All authors (from Columbia unless noted): Keith M. Diaz, Benjamin D. Boudreaux, Chang Xu, Gabriel J. Sanchez, Margaret E. Murdock, Gaspar J. Cruz, Ammie Jurado, Alvis Gonzalez, Melinda J. Chang, Allie Scott, Sung A.J. Lee, Emily K. Romero, Alexandra M. Sullivan, Andrea T. Duran, Joseph E. Schwartz (Stony Brook Renaissance School of Medicine); Ian M. Kronish, and Donald Edmondson.
This study was supported by grants from the U.S. National Institutes of Health (R01HL134985, R01HL128497, and R01HL123368).
The authors report no conflicts of interest.
