Effects of Low-dose Esmolol on Myocardial Injury After Non-cardiac Surgery in Elderly Frail Patients

This topic will focus on the following questions: 1. Part one: To clarify the relationship between preoperative frailty and myocardial injury (cTnT ≥0.03) after non-cardiac surgery in elderly patients; To further explore the predictive factors of myocardial injury after non-cardiac surgery （MINS） in elderly frail patients before operation. 2. Part Two: To explore the effect of low-dose esmolol on myocardial injury after non-cardiac surgery in frail elderly patients.

Esmol is a short-acting selective β-adrenergic receptor blocker, which is often used in patients with cardiovascular diseases or hypertension. It is also used to reduce stress response, control heart rate and reduce myocardial oxygen consumption during perioperative period to effectively protect cardiac function. However, the safety and efficacy of perioperative β-blockers are still controversial due to their possible effects on renal function. Several recent studies have shown that β-blockers reduce perioperative myocardial ischemia and may reduce the risk of perioperative myocardial infarction (PMI) and cardiovascular death in high-risk patients . The 2021 American College of Cardiology /American Heart Association (ACC/AHA )guidelines for coronary revascularization suggest that dose adjustment can optimize the clinical effects of β-blockers, thereby reducing adverse effects during treatment . In addition, several studies have found that continuous intraoperative infusion of low-dose esmolol (5-10μg/kg/min) can reduce intraoperative stress response and maintain hemodynamic stability. The meta-analysis of esmolol by Ollila A et al. found that esmolol has a promising application in the prevention of perioperative myocardial ischemia and serious complications associated with long-term ischemia. Does perioperative Esmolol reduce the incidence of myocardial injury after non-cardiac surgery （MINS）? The safety, outcome and benefit of perioperative esmolol in frail patients are still unclear. Therefore, this study intends to apply the appropriate dose of esmolol to prevent cardiovascular events in elderly frailty patients undergoing non-cardiac surgery, and explore the effect of low-dose esmolol on MINS in elderly frail patients, so as to provide feasible clinical measures for the safe outcome and rehabilitation of frail patients during perioperative period.