Epidemiological research has long shown a link between stress and heart disease. What has been missing is strong evidence showing that reducing stress actually reduces the risk of heart attacks, other cardiovascular events and death—until now.

A study by psychologist James A. Blumenthal, PhD, and colleagues published in Circulation found that adding stress management training to a standard cardiac rehabilitation program not only reduced participants' stress levels, but also nearly halved adverse cardiovascular events, including heart attacks, strokes, severe angina, revascularization procedures and death.

"It's a very important finding," says Blumenthal, a professor of psychiatry in the department of psychiatry and behavioral sciences at Duke University Medical Center. "Studies have typically not shown the benefit of stress management. In fact, many studies have actually found that stress management didn't even result in reductions of stress."

Currently, most cardiac rehabilitation programs don't include stress management, Blumenthal says. The new finding should persuade rehab programs to add such training and offer it to all participants, he says. "Stress management isn't just for those who are distressed, but has benefits for everybody," he says.

In the study, known as ENHANCED, researchers randomly assigned 151 patients with coronary heart disease to 12 weeks of standard exercise-based cardiac rehabilitation or rehabilitation combined with stress management training—educational sessions, group support and cognitive-behavioral therapy. A matched group of patients who were eligible for rehabilitation but didn't attend served as an additional control. The researchers then followed participants for up to five years.

The two rehab groups saw similar improvements in risk factors for and different biomarkers of coronary heart disease, including lipid levels, inflammation and heart rate variability. Both groups had lower rates of recurrent cardiac events than the nonrehab group. The stress management group, however, saw additional benefits. They had lower stress levels than the standard rehab group. More important, just 18 percent of the stress management group had clinical events, compared with 33 percent of the standard rehab group.

"This is the first American clinical trial to reduce psychological stress, cardiac biomarkers and, most important, recurrent cardiac events in more than 30 years," says psychologist Robert Allan, PhD, a clinical assistant professor of psychology in medicine at Weill Cornell Medical College and practitioner at New York-Presbyterian Hospital. "The late, internationally prominent cardiologist Stephen Scheidt, MD, who co-edited the first edition of "Heart and Mind" with me, referred to such a hoped-for reduction in cardiac events as ‘the holy grail of behavioral cardiology.'"

The fact that Blumenthal's study was published in one of cardiology's premier journals should increase its impact on practice, Allan adds.