A high-sensitivity blood test could be used before operations to predict which patients will survive long-term after surgery, and identify those at risk of complications following their operation, according to research presented at the British Cardiovascular Society (BCS) Conference today.
Researchers based at James Cook University Hospital, Middlesbrough, measured the level of troponin in blood samples taken from 993 patients before they underwent elective or emergency surgery. None of the patients had cardiac surgery.
They found that 37 per cent of the patients who had troponin levels of 50ng/l or over before their surgery died within 12 months.
In comparison, only 3.7 per cent of patients with a pre-operative troponin level of less than 17ng/l died within 12 months.
Highly accurate blood test
The troponin test is routinely used in Accident and Emergency departments to diagnose a heart attack. The highly accurate test measures blood levels of the molecule troponin, which is released into the bloodstream when heart muscle is injured.
However, in this study 10 per cent of patients had raised troponin levels without having suffered from any previous cardiovascular events.
The link between the raised troponin levels and an increased death rate after surgery is not yet clear, although the researchers suggest that a high troponin level may show that a person is suffering from underlying inflammation.
To see whether inflammation could explain the increase in death rates, the researchers are now testing the blood samples for other signs of inflammation, such as raised inflammatory markers called C-reaction proteins.
Improving surgical outcomes
Ultimately, the researchers hope to be able to find new ways of improving patients’ survival after an operation.
Professor Metin Avkiran, Associate Medical Director at the British Heart Foundation, said:
“Troponin tests detect injury to heart muscle and are used to diagnose a heart attack. This study suggests that an elevated troponin level in the blood before non-cardiac surgery, in the absence of a heart attack, is predictive of poor patient survival during the first 12 months after such surgery.”
“If we can understand the underlying causes of heart injury in such patients, their treatment may be tailored to improve outcome after non-cardiac surgery.”