ST-Deviation Patterns in Recurrent Myocardial Infarctions

Myocardial infarction (MI) may be classified as ST-elevation MI (STEMI) or non-STEMI (NSTEMI). We used the term "recurrent MI" (RMI) to denote repeat MI episodes in a particular patient in which a different coronary site is responsible for each episode. We investigated whether the type of RMI is more likely to be of the same type as the index MI or whether patients may have the 2 types of MI at random. The analysis included 305 patients who had ≥2 MI episodes. Acute MIs were classified as STEMI or NSTEMI. We attempted to include only MIs of native vessels, without the presence of extracardiac conditions that intensify myocardial ischemia. Most patients (76%) had repeat episodes of the same MI type, i.e., STEMI or NSTEMI. Recurrent STEMI occurred in 44% of patients, recurrent NSTEMI in 32%, and STEMI and NSTEMI in 24%. Thus, most patients with RMI episodes will have STEMIs or NSTEMIs but not the 2 types, suggesting a predilection of some patients to repeat episodes of occlusive thrombi and others to repeat episodes of nonocclusive thrombi.