Perioperative "acute myocardial infarction": is it really acute inflammation (Takotsubo Syndrome)?

Emeritus Professor John Horowitz, University of Adelaide

2020 Vanguard Grant

Years funded: 2021-2023

Survival rates during most forms of non-emergent, major non-cardiac surgery have improved substantially over the past 30 years. However, the occurrence of low blood pressure during the early postoperative period is associated with release of markers of cardiac injury into plasma, suggestive of the occurrence of acute myocardial infarction ("heart attack"). Mortality rates in the 30 days following the occurrence of postoperative hypotension are very high indeed. Over the past 25 years, a number of investigations related to prevention of perioperative "myocardial infarction" have been reported, using interventions such as beta-adrenoceptor blockade, aspirin and clonidine: none of these interventions have improved outcomes. Over the same period of time, the condition of "Takotsubo Syndrome" (TTS) has been increasingly recognised and understood as an acute cardiac and coronary vascular inflammation, occurring predominantly in ageing women in response to acute surges of release of adrenaline, and affecting mainly the contractile performance of the apical region of the left ventricle.

The planned study will evaluate a series of non-cardiac surgery patients for evidence of perioperative cardiac injury, and will characterise the nature of injury, measuring additional markers in plasma, patterns of ECG changes and of contractile anomalies on echocardiography, and correlation of these findings with perioperative severe hypotension. If most perioperative cardiac injury is due to TTS, this will open up a completely new direction in treatment of such patients, identifying high risk individuals and pre-treating these individuals with appropriate inflammation-suppressing drugs.