By Amy Norton
MONDAY, Dec. 4, 2017 (HealthDay News) -- Older adults commonly suffer damage to heart cells during various types of surgery -- even non-heart-related surgeries -- and it can significantly raise their risk of dying from the procedure, a new study finds.
The research looked at a phenomenon called perioperative myocardial injury, or PMI. It refers to subtler heart damage that can happen during or soon after any type of surgery.
Older patients and those who already have heart disease are at increased risk.
However, the condition is easily missed because most of the affected patients have no chest pain or other symptoms, according to Dr. Christian Puelacher, the first author on the new study. He's a clinical researcher at Cardiovascular Research Institute Basel in Switzerland.
Puelacher's team found that PMI may happen more often than doctors have typically thought: Of more than 2,000 high-risk patients they screened, 1 in 7 developed PMI after a non-cardiac surgery, the study found.
"This suggests we've underestimated the number of myocardial [heart] injuries that occur during non-cardiac surgery," said Dr. Alistair Phillips, co-chair of the surgeons' section leadership council for the American College of Cardiology.
The cases were found because all of the patients -- treated at the University Hospital Basel in Switzerland -- were screened for PMI with a newer blood test: a so-called "high sensitivity" troponin test, which detects elevations in the heart protein troponin.
When troponin levels rise, it's a sign of heart damage, Phillips explained.
High-sensitivity troponin tests have been used in Europe and elsewhere for several years, but have only recently become available in the United States. The U.S. Food and Drug Administration approved the first such test earlier this year.
Phillips, who was not involved with the study, said that as such testing comes into wider use, doctors will be able to better manage patients who develop PMI.
The findings are based on more than 2,000 patients who underwent non-cardiac procedures ranging from knee and prostate surgeries to hip replacements and gallbladder removal.
All of the patients had their troponin levels measured before and after surgery because they were considered high-risk for PMI: They were either older than 65, or had a history of heart disease, stroke or peripheral artery disease (clogged leg arteries).
Overall, 1 in 7 developed PMI. And those patients had a six times higher death rate in the 30 days after surgery: 9 percent died, versus only 1.5 percent of patients without PMI.
Most often, the study found, patients had no telltale signs of heart damage. Only 6 percent had chest pain, while 18 percent had any symptoms to signal that blood and oxygen flow to the heart was being impaired.
According to Puelacher, the findings offer some "first hints" that systematic screening for PMI can benefit patients.
There is no single PMI treatment. "Responses need to be tailored," Puelacher said. "PMI can have a range of causes and the management strategy needs to be chosen appropriately."
That could mean medication, Phillips said -- using a beta blocker to control a patient's heart rate, for example, or prescribing a statin.
Doctors could also screen for coronary heart disease (blocked heart arteries) in patients who have never been diagnosed with it, Puelacher said.
No one is saying older patients, or those with heart disease, should avoid a needed surgery.
According to Phillips, the message is positive rather than "alarming."
"We now have a new tool that should help us better screen patients post-surgery," he said.
The research does not address the question of whether some patients should avoid an elective procedure in the first place, according to Puelacher.
All of the study patients, he said, were cleared for surgery after a thorough evaluation.
"Preoperative evaluation is usually done very thoroughly in routine clinical practice, taking into account risk factors such as heart disease," Puelacher said.
"Our data," he added, "suggest an option [for] improving care and outcomes after a surgery has taken place."
The study findings were published in the Dec. 4 online issue of the journal Circulation.