Abstract 9326: Peri-Operative Myocardial Damage in Higher-Risk Patients Undergoing Elective Non-Cardiac Surgery

Abstract

Introduction: The development of high-sensitivity assays has greatly improved the analytical performance of cardiac troponin, allowing detection of very minor damage to cardiac muscle. High sensitivity troponin (hsTnT) is elevated in subgroups of stable populations, with prognostic significance. We postulated hsTnT would be elevated in a proportion of patients undergoing elective non-cardiac surgery, with this elevation predicting adverse peri-operative events. Aims: The aims of our study were to identify the incidence of elevated hsTnT in patients undergoing non-cardiac surgery, and to determine the association between elevated pre-operative hsTnT and adverse peri-operative events. Methods: Consecutive patients aged ≥45 years undergoing major elective non-cardiac surgery, prescribed anti-platelet therapy for primary or secondary cardiovascular event prevention, were included. Baseline, 24 and 48-hour post-operative hsTnT (Roche Diagnostics, 99th percentile 13ng/L) were collected, an elevation above the 99th percentile or if baseline hsTnT elevated, a delta value of 30%, used to define myocardial damage. Results: Included in the analysis were 160 consecutive patients undergoing elective non-cardiac surgery (mean age 72.3 ± 9.7 years, 66% male). Baseline hsTnT was elevated in 29.5% of all patients. Peri-operative myocardial damage occurred in 28.6% of patients. Independent predictors of peri-operative myocardial damage included age (HR 1.07, 1.02-1.12), intra-operative hypotension (HR 3.65, 1.34-9.91), and pre-operative haemoglobin (Hb) concentration (HR 0.97, 0.95-0.99). Baseline elevated hsTnT did not predict peri-operative myocardial damage. Myocardial infarction as defined by the Universal Definition occurred in only 2.7% of patients. Conclusions: Although pre-operative hsTnT was commonly elevated in this cohort, there was no significant association with post-operative myocardial damage. We found 28% of stable higher-risk patients undergoing elective non-cardiac surgery have hsTnT determined peri-operative myocardial damage. The significant associations of intra-operative hypotension and pre-operative Hb concentration suggest myocardial damage is predominantly due to a supply and demand mismatch.