Key in blood test
Even patients who undergo non-cardiac surgery are at risk of cardiovascular complications including death. Simply the stress, inflammation and clotting from any number of surgeries could predispose the heart to injury. Across the world, more than one million adults die within months of non-cardiac surgery each year.
For this reason, experts closely assess patients post-surgery to ascertain their risk of complications. Researchers have shown that a simple blood test can help identify patients who are at increased risk of death after surgery and therefore would benefit from more intensive monitoring and management following surgery.
Testing a patient’s level of troponin, which are certain proteins that are released when the heart muscle has been damaged, is the key. The more damage there is to the heart, the greater the amount of troponin T and I there will be in the blood.
The VISION study (Vascular Events in Non-cardiac Surgery Patients Cohort Evaluation) is a large global study evaluating major complications after non-cardiac surgery. Researchers set out to clarify the danger levels of troponin, as the optimal troponin threshold is not well established.
“We assessed over 15 000 patients across the world to clarify the relationship between troponin measurement after non-cardiac surgery and the incidence of death within 30-days of surgery,” said author Dr Clara Chow who led the Australian arm of the study at The George Institute and Westmead Hospital.
“We found that a certain level of troponin in the first three days after surgery strongly predicts a patients survival. Currently troponin levels are not part of routine post-surgical care. However our results show the benefit of tracking these levels early” Dr Chow added.
VISION enrolled 15,133 adult patients in North and South America, Asia, Australia, and Europe who had a Troponin T measurement daily during the first three days after surgery. Patients were followed in hospital and at 30 days after surgery. The study was published in the Journal of the American Medical Association.
Based on guideline recommendations, many laboratories consider a Troponin T measurement >0.04 ng/ml abnormal. VISION demonstrated that Troponin T (TnT) values below the commonly used threshold of 0.04 (ie., 0.02 and 0.03) were strongly associated with 30-day mortality. Recruitment of all patients in Australia was funded by the George Institute NHMRC program grant APP 571281.
Access the full article at the JAMA website.