553 Smoke but No Fire: Increased MINOCA and Takotsubo Acute Coronary Syndromes in the Australian Bushfires

Abstract

The 2020 Australian bushfires led to declaration of a state of emergency in multiple states. Concerns have previously been raised that smoke exposure may trigger increased rates of acute coronary syndrome, Takotsubo (stress) cardiomyopathy, and cardiac arrest. Our hospital is a major tertiary receiving hospital for Albury-Wodonga and East Gippsland, two areas most affected by the 2019/2020 bushfires. We performed a case-control analysis of acute coronary syndrome patients transferred from these regions between 29th December 2019 to 10th January 2020. Cases were compared to acute coronary syndrome cases in the identical date range from the two years prior. 11 patients were transferred from the bushfire-affected regions, representing an increase of 24.5% in case volume from previous years. All bushfire-affected patients had chest pain and elevated troponin level, with median troponin value 1,271ng/L (interquartile range 546 - 6,807ng/L, normal <16ng/L). In comparison with the control group, bushfire-affected patients were more commonly female (45.5% from bushfire areas vs 14.8% in the control group, p=0.044) and received a diagnosis of myocardial infarction with normal coronaries (MINOCA) or Takotsubo cardiomyopathy (45.5% vs 7.4%, p=0.021). There was no difference between groups in median age, presence of smoking history, median number of cardiovascular risk factors, median troponin level, or electrocardiogram appearance. Our experience demonstrates that the greatest increase in case volume was in middle-aged females (median age 62.4 years) experiencing either a MINOCA event or Takotsubo cardiomyopathy in the context of high levels of community stress.