Boden

BOSTON (CNN) -- Patients who suffer mild heart attacks actually might be better off if they aren't subjected to invasive diagnostic procedures and surgical techniques such as angioplasty or bypass surgery, according to the results of a new study.

In the study, reported in the latest issue of the New England Journal of Medicine, researchers evaluated 920 patients at 17 Department of Veterans Affairs hospitals around the country who had a type of mild heart attack known as a non-Q-wave myocardial infarction. About 55 percent of all heart attacks are of that type.

What they found was that patients who were given the most elaborate tests and treatments were two to three times more likely to suffer a second heart attack or die within 30 days than those who were diagnosed and treated with non-invasive therapies, such as exercise stress tests and drugs that dissolve blood clots.

The lead author of the study, Dr. William Boden of the Veterans Affairs Medical Center in Syracuse, New York, termed those findings "astonishing."

"We all need to collectively step back and reassess what we're doing here," Boden said.

Currently, heart attack patients in the United States are routinely subjected to a procedure called coronary angiography, in which a tube is threaded through an artery into their heart. About half the time, that test leads to bypass surgery or angioplasty, in which blocked arteries are opened with a balloon-like device.

But based on their findings, researchers concluded that about 400,000 to 600,000 Americans each year could avoid angiography, which costs $20,000 to $25,000.

Instead, their condition could be assessed with stress tests, electrical heart monitoring and other measures that don't involve cutting or inserting devices into the body. Invasive procedures would be used only if the non-invasive procedures indicated that a patient's condition specifically warranted them.

That's how mild heart attacks are treated in Canada and Europe. But American doctors have been reluctant to follow suit, despite three previous studies that have shown that aggressive treatment does not save lives and may actually increase risks for some patients.

In a commentary accompanying the study in the New England Journal, Dr. Richard Land and Dr. David Hillis of the University of Texas Southwestern Medical Center in Dallas concluded that one reason for the reluctance to change may be that doctors who avoid angiography and angioplasty may be accused of giving lackluster treatment.

In addition, Land and Hillis said there are a large number of doctors trained to perform aggressive techniques -- and money to be made if those procedures are performed.

Boden -- who terms the use of routine aggressive treatment "a big industry" -- says he doesn't believe the results of his study will alter doctors' behavior. But he believes cost-conscious insurance companies and HMOs will eventually force doctors to change their approach.

The study looked at patients 30 days and one year after their heart attacks. While those treated conservatively with non-invasive techniques were less likely to die or suffer another attack in the first 30 days than those treated aggressively, the two groups had about the same risk after one year.

"The question is what happens two, three and four years down the line or even further than that," said Dr. Steven Eisenberg of St. Joseph's Hospital in Atlanta.

Senior Medical Correspondent Dan Rutz and Reuters contributed to this report.