PERIOPERATIVE MYOCARDIAL-CELL INJURY - THE ROLE OF TROPONINS

Early recognition of minor myocardial cell injury and appropriate trea tment may prevent development of myocardial infarction as one of the m ost severe postoperative cardiac complications. Troponins have been sh own to be sensitive biochemical markers for the assessment of myocardi al cell injury. We investigated prospectively 67 cardiac risk patients undergoing elective non-cardiac surgery. Troponin T (TNT) concentrati ons were measured during the perioperative period, and in those patien ts with increased TNT (cut-off 0.2 ng ml(-1)), troponin I (TNI) concen trations were measured additionally (cut-off 0.6 ng ml(-1)). Patients were allocated to one of three groups: group I, all patients with norm al TNT concentrations had a good cardiac outcome (80.5%). In those pat ients with increased TNT concentrations (19.5%) TNI was also positive; group II, patients (8.8%) with only slightly increased TNT concentrat ions (0.32-0.99 ng ml(-1)) also had a good outcome, indicating minor m yocardial cell injury, whereas patients with cardiac complications (11 .9%) had higher TNT concentrations (0.47-9.8 ng ml(-1)) (P <0.05) (gro up III). With a TNT cut-off at 0.2 ng ml(-1), the positive predictive value for adverse outcome was 61.5%; the negative predictive value was 100%. With a TNT cut-off at 0.6 ng ml(-1), the positive predictive va lue for adverse outcome increased to 87.5%, but the negative predictiv e value was still high (98%). Most of the patients showed an increase in TNT content from the day of surgery until the third postoperative d ay. We conclude that serial troponin measurements during the periopera tive period identify pre-, intra- and postoperative myocardial cell in jury. The concentration of troponin T may reflect the degree of injury and help categorize the subsequent risk.