Study on the Correlation Between Intraoperative Hypotension and Postoperative Myocardial Injury

The investigators are conducting an important study aimed at better understanding and predicting a potential complication after non-cardiac surgery: myocardial injury. This research is crucial for enhancing surgical safety and improving patient outcomes. Simply put, postoperative myocardial injury (PMI) means that heart muscle cells are damaged after non-cardiac surgery. While it might not cause obvious chest pain like a heart attack, it can show up as abnormalities on an electrocardiogram (ECG) or in blood tests (like elevated troponin levels). This type of injury is a significant factor contributing to postoperative complications and even mortality. During surgery, hypotension-or low blood pressure-is a common occurrence. The investigators know that maintaining adequate blood pressure is essential for the heart to receive a sufficient blood supply. If blood pressure drops too low, the heart's blood supply can be reduced, potentially leading to oxygen deprivation and damage to heart muscle cells. While it's widely accepted that low blood pressure is linked to myocardial injury, precisely defining "low blood pressure" during surgery has been a persistent challenge. * Historically, the investigators have focused on the "absolute value" of blood pressure, such as a fixed mean arterial pressure (MAP) threshold (e.g., below 65 mmHg). Many studies have indeed shown that MAP below 65 mmHg, especially for extended periods, increases the risk of PMI. * However, recent research is starting to challenge this perspective. Some studies have found that even maintaining a relatively higher blood pressure during surgery (e.g., MAP above 75 mmHg) didn't significantly reduce the incidence of PMI. This suggests that simply looking at a fixed blood pressure number might not tell the whole story. Our preliminary research uncovered an intriguing finding: even if a patient's absolute blood pressure value during surgery seemed acceptable (e.g., above 60 mmHg), their risk of postopera