Detection and management of asymptomatic myocardial injury after noncardiac surgery

Surgery and the subsequent recovery are serious circulatory stress tests that may result in symptomatic cardiac events in vulnerable patients.1–3 Despite efforts to prevent the occurrence of postoperative adverse events, myocardial infarction following noncardiac surgery remains common.1–3 Even more worrisome, the typical symptoms of myocardial ischaemia, such as chest pain, are easily masked by postoperative pain treatment including opioids. As a consequence, the clinical course of postoperative myocardial infarction is mainly silent.3 Yet, cardiac morbidity and mortality rates in patients with asymptomatic postoperative myocardial infarction reportedly are similar to those among patients with a clinical diagnosis of myocardial infarction.1,3 As postoperative myocardial infarction may go largely undetected, the available evidence further indicates significant elevations of risk in postoperative patients with increases in circulating biomarkers reflecting cardiac cell damage, such as troponin, but without a conventional clinical diagnosis of myocardial infarction.3–8 Silent myocardial injury, as documented by elevated cardiac biomarkers, may occur in 10–20% of the patients undergoing noncardiac surgery.3,5 A meta-analysis of studies in such patients showed isolated troponin elevations to be a strong independent predictor of mortality within the first year after surgery.5,6 Moreover, the VISION study, including over 15,000 noncardiac surgery patients, showed a strong association between any troponin elevation after surgery, which occurred in 11% of the patients, and 30-day mortality.6 After implementing routine postoperative troponin monitoring in elderly noncardiac surgery patients at our institution, we found similar results: 19% of the patients had a troponin elevation following surgery and such elevation was significantly associated with 30-day mortality.9 These patients go largely undetected, and if detected, clinical guidelines for the management of isolated increases in cardiac biomarkers do presently not exist.