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Discovery of Morning Peak in Heart Attacks Happened by Chance With AM-Getting Up

March 9, 1991

BOSTON (AP) _ Dr. James Muller made his big discovery by asking the wrong question.

While Muller was working on a federally funded study of heart attack victims in 1985, someone noticed that hospitals were enrolling fewer patients in the study in the summer than in the winter. Muller decided to do a computer search to see if heart attacks really were more frequent during the winter.

″I thought that while we were at it, let’s check the day of the week and the hour of the day,″ he recalled. ″I had no prior hypothesis. I just knew it would be easy to do.″

A month later, the computer printouts came back. There was no seasonal difference. But there was an unexpected increase in morning heart attacks.

Muller assumed there was a good explanation for that.

″Probably people had their heart attack pain start at 2 a.m., but they didn’t feel it until they woke up at 8 a.m. That was my first thought,″ he said.

This study, however, gave Muller a way to settle the question. When patients arrived at the hospital, they gave blood samples to measure creatine kinase, an enzyme that rises as a result of heart damage. Because this enzyme goes up in a predictable way after a heart attack, it serves as a kind of clock, revealing exactly when the attack occurred regardless of when the patient noticed pain.

″So I sent it back to the data center and said, ’Let’s have a plot of the time of day versus creatine kinase,‴ Muller said. ″The data came back with a more prominent morning increase.″

Muller, who now is chief of cardiology at New England Deaconess Hospital, then searched previously published studies and found that several other researchers over the years also had noticed a morning increase in heart attacks.

″But all of those studies had been based on pain rather than creatine kinase, and they had been discarded,″ he said. ″People hadn’t paid any attention to them. The thing that established this as fact was the creatine kinase timing.″

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