The levels of high-sensitivity troponin after cardiac surgery that signal an increased risk of death within 30 days are substantially higher than the currently recommended threshold, new research suggests.

Conventional wisdom states that cardiac troponin levels that are 10-70 times higher than the upper reference limit indicate a perioperative MI or clinically important periprocedural myocardial injury.

But according to the VISION (Vascular Events in Surgery Patients Cohort Evaluation) Cardiac Surgery group — which included some 500 Australian patients — these limits may be wildly off the true mark.

Chief author and cardiologist Dr PJ Devereaux said real-world experience — where troponin levels in excess of the 10-fold limit without adverse outcomes being a common occurrence — had “led to a lot of cardiac surgeons ignoring troponin because they think it does not matter”.