Recognition and management of posterior myocardial infarction: a retrospective cohort study

Characteristic electrocardiogram (ECG) features of posterior myocardial infarction (PMI) do not include typical ST-segment elevation and, therefore, carries the risk of delayed diagnosis and management. The aim of this study was to investigate how well PMIs are recognised and whether a lack of recognition translates to a larger infarction. This was a retrospective cohort study of patients sourced from a cardiac catheterisation database. Based on ECG analysis, patients included in this study included those meeting PMI criteria and those meeting ST-elevation myocardial infarction (STEMI) criteria as the control group. Door-to-balloon times were used as an outcome measure for differences in recognition between PMIs and other STEMIs. Troponin was used as a surrogate marker to measure degree of myocardial damage. There were 14 patients meeting PMI criteria and 162 meeting STEMI criteria. PMI patients had significantly longer door-to-balloon times. There was no statistically significant difference between PMI and STEMI group initial troponins t(169)=1.05, p=0.30, or peak 24-hour troponins t(174)=-1.73, p=0.09. In conclusion, using door-to-balloon times as a marker for recognition, this study illustrated that patients suffering PMI experience delayed recognition and management compared with non-PMI STEMIs. This did not, however, result in a significantly larger size of infarction as shown by peak troponin levels.