They also controlled for cardiovascular disease risk factors, such as high blood pressure, smoking and obesity, and lifestyle factors, like alcohol consumption and exercise. But still, job stress was seen as a solid predictor of a repeat attack.
Some experts remain skeptical, citing a variety of confounding factors.
"If you look at enough variables, something is going to turn up that is statistically significant," says Dr. Steven Nissen, chairman of the department of cardiovascular medicine at the Cleveland Clinic Foundation. "Compared with controllable risk factors, such as smoking, job stress is likely to be a minor factor at best."
But others disagree, and say the study shows there is a need to reduce stress in the workplace.
"I think this is an important study that further strengthens the case for assessing psychosocial factors, like job strain and depression, in all patients with coronary heart disease," says Williams. "It means we should really start to develop and test behavioral interventions that can reduce these psychosocial risk factors."
David agrees that employers have a responsibility to ensure the good health of their employees. Recalling the story of one 50-year-old patient who had just had open heart surgery, David notes, "He was lying on a hospital bed with a big scar on his chest, and the first thing he asked me is if I could fill out these papers so he could get paid. He had just had open heart surgery, and he had to worry about these papers."
Of course, the ideal solution would be to change the workplace so that workers have fewer demands and more control, but that is not always so easy in the global market.
For the present, doctors recommend cardiac rehabilitation after surviving the first heart attack, and stress management skills to prevent a second one.
"Everyone who has suffered from a heart attack should go through cardiac rehabilitation," David says. "You go through a facility that emphasizes diet, exercise and stress management. It's a six- to eight-week program that is covered by most insurance companies."
In addition, Williams believes workers can learn to manage their stress better at work.
"I see the best hope being to train the workers in stress-coping skills, so that they will be more resilient and resistant to the health-damaging effects of high-strain jobs," he says.
During a distressing situation, Williams emphasizes the need to be aware of your thoughts and feelings, and to make rational decisions to either change your thoughts, by relaxing, or to change the situation, by using constructive problem solving.
"Relationship skills — speaking clearly, listening, empathy and increasing positives in encounters with others — can also reduce the frequency [with which] you are exposed to distressing situations, and can increase your social support levels," he says.