Perioperative myocardial infarction/injury after noncardiac surgery

Cardiovascular complications, particularly perioperative myocardial infarction/injury, seem to be major contributors to mortality after noncardiac surgery. With surgical procedures being very frequent (900 000/year in Switzerland), perioperative myocardial injury is common in everyday clinical practice. Over 80% of patients experiencing perioperative myocardial injury do not report symptoms. Therefore perioperative myocardial injury remains undiagnosed and untreated. Moreover, its silent presentation results in limited awareness among both clinicians and the public. Despite being largely asymptomatic, perioperative myocardial injury increases 30-day mortality nearly 10-fold. This review aims to increase the awareness of perioperative myocardial injury/infarction and give an overview of the emerging evidence, including pathophysiology, clinical presentation, prevention, and potential future treatments. Summary: postoperative myocardial infarction/injury vs acute myocardial infarction Currently, clinical awareness of PMI is often insufficient. To close this review, we want to compare PMI to a well-known and related disease, spontaneous AMI. First and most important, the vast majority of patients experiencing a PMI do not report acute chest pain or other symptoms typical of spontaneous AMI. Most likely, this is because these PMIs occur in a phase of intense postoperative analgesia [2, 3, 5, 7–9]. Accordingly, most patients with PMI are currently not detected in routine clinical practice. Missed diagnosis is invariably associated with a missed opportunity for the initiation of treatment. Second, the predominant pathophysiology of PMI is only incompletely characterised (plaque rupture versus supply/demand mismatch versus toxic) [14]. Third, because of our lack of knowledge regarding pathophysiology, it is unclear whether the benefit of treatment in PMI is similar to the huge benefit in spontaneous AMI. Fourth, in contrast to spontaneous MI, where cardiac troponin elevations must be accompanied by symptoms, electrocardiographic, or imaging criteria [10, 52], the limited applicability (chest pain in a period of intense postoperative analgesia) and sensitivity (ECG, imaging) of these criteria in the perioperative setting highlight the need for a different diagnostic approach for PMI, which needs to be defined.