Invasive diagnosis and treatment of mild heart attacks may harm patients more than help, according to Department of Veterans Affairs researchers.
That surprising conclusion challenges conventional wisdom concerning the treatment of what are known as non-Q-wave heart attacks, which account for half the 1.5 million heart attacks that strike Americans each year.
The VA study could prompt a fresh look at best practices for managing this common form of heart attack and support a shift to less costly approaches. Besides saving direct costs related to surgery or angioplasty, patients in the VA study who were conservatively treated had hospital stays 1.3 days shorter than the average 9.5 days for the intensively treated group.
Cardiologists currently recommend these relatively mild heart attacks be aggressively treated, usually with angioplasty or bypass surgery, because they are believed to herald subsequent more serious attacks.
Not surprisingly, the VA study met with considerable skepticism among many cardiologists.
"It flies in the face of everything we know about non-Q-wave myocardial infarction," said Peter Counihan, M.D., a cardiologist at University of Pittsburgh Medical Center. He cautioned more data are needed and that the VA approach "should not be promulgated as practice."
Christopher Cannon, M.D., a cardiologist at Brigham and Women's Hospital, Boston, said other studies of aggressive treatment in less elderly and sick patients than those in the VA group did not show a significant increase in deaths and repeat heart attack rates.
Nevertheless, Cannon said, the VA study raised an important cautionary flag. "It may not be the best thing to go rushing in with all heart attack patients. This study is a good reminder that doing noninvasive testing first is reasonable."
Significantly, VA researchers found no improvement in outcomes for patients following the common course consisting of angiographic diagnosis followed by bypass surgery or balloon angioplasty-depending on the number of blocked blood vessels-as compared to patients who were noninvasively diagnosed and treated.
"Patients treated conservatively do as well, if not better, than patients managed with invasive strategies," said William E. Boden, M.D., director of medical service at VA Upstate Health System, Syracuse, N.Y. Boden led the study at 15 VA hospitals involving 920 patients between 1992 and 1996. He reported the results last month at the American College of Cardiology's annual scientific meeting in Anaheim, Calif.
Surprisingly, patients in the invasive treatment group had significantly higher rates of death and repeat heart attacks than those in the conservatively treated group.
At the time of hospital discharge, 7.8% of aggressively treated patients had died or had a repeat attack, compared with 3.3% in the conservative group.
At one month, nearly twice as many invasively treated patients, 10.4%, had died or suffered another attack, compared with the 5.7% rate among the conservatively managed group. At one year, nearly a quarter, or 24%, of invasively treated patients had died or had another attack, compared with 18.6% of patients in the conservative group.
Long-term outcomes favored the less-invasively treated patients as well. Overall, patients treated invasively had death rates 34% higher than those treated conservatively.
Doctors warned that the VA results should not be applied to women, because they accounted for only 3% of the study's patients. Although women experience less coronary disease than men, women have significantly higher fatality rates.
Boden said the VA plans to do a detailed cost-effectiveness analysis using data collected during the medical trial. But that effort, he said, has not yet begun.