Characteristics, Management, and Outcome of Transient ST-elevation Versus Persistent ST-elevation and Non-ST-elevation Myocardial Infarction

Patients with acute myocardial infarctions (AMIs) present as persistent ST-elevation myocardial infarction (STEMI) or as non-ST-segment elevation myocardial infarction (NSTEMI). In some patients with STEMI, ST elevations are transient and resolve before coronary intervention (transient ST-elevation myocardial infarction [TSTEMI]). We analyzed our registry comprising all consecutive patients with AMI admitted during 2009 to 2014, and compared the characteristics, management, and outcome of patients with TSTEMI with those of patients with STEMI and NSTEMI. Of 1,847 patients with AMI included in the registry, 1,073 patients sustained a STEMI (58%), 649 had a NSTEMI (35%), and 126 presented with TSTEMI (6.9%). Patients with TSTEMI were younger than patients with NSTEMI and STEMI (56.5 vs 62.8, p <0.001, and 59.5 years, p <0.02, respectively), smoked more (77.8 vs 54.0, p <0.001, and 62.1%, p <0.0005), and fewer were hypertensive (52.4 vs 74.2% and 58.8%, both p <0.001) and diabetic (26.2% vs 47.7%, p <0.0001, and 36.9%, p <0.02). The extent of coronary artery disease in patients with TSTEMI was similar to that of patients with STEMI except for less involvement of the left anterior descending artery (p <0.001), but less extensive than in NSTEMI patients. TSTEMI involved less myocardial damage by troponin-T level (p <0.005) with better cardiac function (LVEF 61% vs 55% and 49%, both p <0.0001). Mortality was lower among TSTEMI both in-hospital (0 vs 2.3% [p = NS] and 4.2% [p <0.01]) and long-term (4.8% vs 14.7% and 14.2%, both p <0.003) at a median of 36 months. In conclusion, TSTEMI is an acute coronary syndrome distinct from NSTEMI and STEMI, characterized by fewer risk factors, a similar extent of coronary artery disease to STEMI, but is associated with less myocardial damage and portends a better outcome.