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NEW YORK (Reuters Health) - After a heart attack, waiting at least 2 months before an elective surgery is linked to a lower risk of dying or having a second heart attack, a new study of Californians says.
Patients who've had a heart attack should wait at least 8 weeks before surgery, said Dr. Christian de Virgilio, professor of surgery at the UCLA School of Medicine.
However, doctors "have to balance risk of heart attack versus the risk of delaying surgery," said de Virgilio, who co-authored the study published in the Annals of Surgery.
In an analysis of outcomes for more than half a million people in a California hospital database, 16 out of 50 who had surgery less than a month after a heart attack had a second heart attack within 30 days, compared to 4 in 50 that waited at least 2 months.
The risk of a second heart attack declined dramatically the longer a patient waited before having one of five non-cardiac elective surgeries, such as hip replacement or gallbladder removal.
Of those having surgery between 31 and 60 days after the initial heart attack, 10 in 50 had a second attack; between 61 and 90 days, 4 in 50 had a second attack; and between 3 months and 6 months, just 3 in 50 had second heart attacks.
The American Heart Association (AHA) and American College of Cardiology jointly recommend that people wait 4 to 6 weeks after a heart attack before having surgery, but this new research shows that the risk persists after that period, de Virgilio told Reuters Health.
"We've always kind of known that patients that have had a recent heart attack are at a higher risk of another after surgery, but a lot of that data is based on studies done decades ago," said de Virgilio, who co-authored the study.
To find out if modern anesthesia practices and pre- and post-surgical treatments have reduced the riskiness of having surgery after a heart attack, de Virgilio and his colleagues looked at the medical records of 563,842 people who had undergone elective surgeries between 1999 and 2004. About 3 percent had also had a heart attack within the year before the surgery; their average age was 69.
Heart attack "still remains a very high risk factor for patients requiring surgery," de Virgilio said, "and it's a higher, more persistent risk than we thought."
The danger was not only a second heart attack, but an increased risk of dying after surgery as well.
Among the patients who had a heart attack within the previous month, 7 out of 50 died. If the patients waited at least two months, 5 out of 50 died.
The death rate is somewhat high, probably because many of the patients had to have emergency surgery, de Virgilio said.
About 8.5 million adults have a heart attack each year in the U.S., according to the AHA.
The risks related to recent heart attacks were not unique to one specific type of surgery, de Virgilio noted.
"Any surgery creates stress," which can affect heart function, he said.
The biggest change in managing heart attack since the earlier studies has been the use of statins, which lower cholesterol and have anti-inflammatory properties that protect the heart during surgery, de Virgilio said.
However, this study did not look at which treatments were given to whom, said Dr. Edward McFalls, professor of medicine at the University of Minnesota in Minneapolis.
"We don't know from the study what therapy was given that might have influenced the patient in a good and a bad way," McFalls, who did not work on the study, told Reuters Health.
This research "supports the guidelines statement that there should be a grace period or waiting period," McFalls said, but whether these guidelines should be extended is still up in the air.
SOURCE: bit.ly/eQ9oZ6 Annals of Surgery, online March 2, 2011.