Lay Had History of Heart Disease, but Did the Stress Do It?

Stressful is perhaps the best way to sum up the last year of Ken Lay's life.

In May the former CEO of the Enron Corp. was convicted of defrauding investors and employees by repeatedly lying about Enron's finances. He was expected to receive a long jail sentence in October.

So, it didn't come as much of a surprise to learn that he died last night of an apparent heart attack. One, he was under a lot of strain. And, two, he had been treated for heart disease for at least the last decade, ABC News learned today.

In the mid '90s, Lay was put on a cholesterol-lowering statin drug. Around five years ago, his coronary disease had progressed to a point where his doctors decided to put in at least one stent -- a wire mesh device -- in one of his arteries to try to prevent a future heart attack. A source told ABC News at the time the stent was put in that Lay had what was described as stable coronary disease.

In other words, he was not viewed as at imminent risk for a heart attack, but the stent was put in as a protective measure. Lay was treated by cardiologists at the University of Texas at Houston, and had also been treated with aspirin and given a modified diet for his heart disease.

Lay also was concerned about his condition. He had put portable heart defibrillators, which can be used to restart the heart, in his houses and on his airplane, reported Christi Myers, of ABC Houston affiliate KTRK.

Clearly, Ken Lay was at risk for a fatal heart attack. Just not at a huge risk, because he was already getting attentive medical care. So did the stress finally do it to him?

It's hard to know, said doctors. Certainly, there's a public perception that stress can cause heart disease -- an unscientific poll today revealed that the majority of readers believe both stress and an unhealthy lifestyle cause heart attacks. (Poll available here).

However, it's hard to prove a direct cause-and-effect link. The American Heart Association lists stress as a possible risk factor for heart attacks, but it's not one of the major known risk factors.

"The reason that the [AHA] and others have not made depression and stress a risk factor for death after myocardial infarction [a heart attack] is that the whole concept of stress is very hard to define," said Dr. Brian Olshansky, director of cardiac electrophysiology at the University of Iowa Hospitals. "What is stressful for one person may not be stressful for another person."

What's known for sure is that Ken Lay's professional situation probably didn't help things. He may have even suffered from a known phenomenon called the broken heart syndrome, noted several doctors.

"Sudden cardiac death increases after general calamities such as 9/11, the San Francisco earthquake, etc. ... Extensive grief, irreparable loss -- a death of spouse, loss of job or house -- are known precipitators," said Dr. Douglas Zipes at Indiana University, who's a former president of the American College of Cardiology, in an e-mail.

But not all doctors agreed.

"I don't buy the 'stress causes heart disease' paradigm," said Dr. Steven Nissen, current president of the American College of Cardiology. "Our species is well adapted to deal with stress, and most of us don't die suddenly when life gets complicated."

Without knowing Lay's medical history, experts are not exactly sure how strong a role either heart failure or stress played in his death. If he had a previous heart attack, for example, this would have placed Lay at greater risk for another one.

Zipes added that it's also possible Lay didn't die from a heart attack but instead from heart failure.

Heart attacks are caused by the blockage of blood flow to the heart -- usually from fat clogging the arteries -- whereas heart failure is a disruption of the heart's electrical rhythm.

Regardless, the important thing to keep in mind, doctors said, is that heart disease is the leading cause of death in the United States.

According to Dr. Clyde Yancy, medical director of the heart failure and transplantation department at the University of Texas Southwestern Medical Center, "We are all at risk, not just CEOs, but the everyday men and women as well."