Background: Acute myocardial stunning, herein defined as the reversible loss of myocardial function, occurs in both takotsubo syndrome (TS) and ST-elevation myocardial infarction (STEMI), and can be life-threatening in both conditions. However, despite typically having considerably more pronounced myocardial stunning, TS patients have better prognosis than patients with STEMI. Despite the different relationship between extent of myocardial stunning and prognosis in TS vs STEMI, no 'head-to-head' comparison of the myocardial stunning phenotypes in TS vs STEMI has been done.

Methods: The Stunning In Takotsubo and Acute Myocardial Infarction (STAMI) study is a single-center, prospective clinical study that will enroll 100 patients with STEMI and 25 patients with TS. Echocardiography, laboratory testing (including troponin and NTpro-BNP), and ECG will be done immediately after angiography and at days 1, 2, 3, 7, 14 and 30. The primary endpoint is the proportion of myocardial stunning that has resolved after 72 hours, as determined by echocardiography. Total myocardial stunning is defined as the extent of akinesia observed at day 0 that resolves by day 30.