Silent heart attacks a significant risk following surgery

Teresa Tanoos's picture
Silent heart attack
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Approximately 80% of heart attacks after surgery are clinically silent, without any physical signs or symptoms that reveal they’ve occurred.

Accordingly, attendees at this week’s Annual Congress of the Association of Anesthetists of Great Britain and Ireland (AAGBI) are calling for increased awareness of postoperative “silent” heart attacks.

This includes researchers from Cleveland Clinic, who will present evidence that about one in 11 patients having major non-cardiac surgery will have a heart attack – and, among these, one in 10 will die within 30 days of the operation.

The only was such heart attacks can be detected is by testing blood for the biomarker troponin.

Professor Daniel Sessler of Cleveland Clinic in Ohio will make the presentation, emphasizing that just a few post-surgery patients ever receive blood testing for troponin, although data is available that indicates many more patients should get their blood screened, so that timely treatments can be provided if they suffer a silent heart attack following surgery.

"Blood concentration of troponin is the best indicator of a post-surgical heart attack. Furthermore, the test for troponin is inexpensive, quick, and accurate," explains Prof. Sessler.

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"Many of these patients appear outwardly to be recovering well from their surgery,” adds Sessler.

“In four of five patients who have a postoperative heart attack, there are no clinical symptoms or signs, no chest pain or shortness of breath, and electrocardiograms and echocardiograms are normal,” he says. “Clinicians will thus miss most of these heart attacks without specific blood testing for troponin."

According to Sessler, there are different options for treating silent heart attacks after surgery. At the very least, he says that patients should be started on aspirin therapy, while additional options include angiography and coronary artery stenting, or treatment with anticoagulant drugs.

Meanwhile, information on the prevention of heart attacks remains limited, but a major trial of low-dose clonidine and low-dose aspirin involving 10,000 patients, will be completed by the end of this year, which may be provide additional insight.

"Available data, though, indicate that low blood pressure during surgery is strongly associated with both kidney injury and heart attacks. In most cases, anesthesiologists can prevent levels of hypotension that might be dangerous by giving less anesthesia or drugs that raise blood pressure." concludes Sessler.

According to AAGBI President Elect Andrew Hartle, these are “important findings with implications for improving patient care and making surgery even safer than it already is."

Some 240 million non-cardiac surgeries are carried out worldwide each year. Sessler estimates that at least a third of these would be moderate-to-high risk operations.

SOURCE: AAGBI Annual Congress 2013

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