Acute ST elevation myocardial infarction with angiographically normal coronary arteries: Causes and outcomes

A minority of patients presenting with ST elevation myocardial infarction (STEMI) have angiographically normal coronary arteries. We aimed to assess its incidence, identify possible aetiologies and determine long-term prognosis. We retrospectively analysed 714 consecutive patients presenting with STEMI over a 10-year period (1995 to 2005), and identified 41 patients with angiographically normal coronary arteries. Mean age was 44 ± 15 years; the majority were male. Specific diagnoses were made in 13/41 (32%) patients, including peri-myocarditis (11/41) and Takotsubo cardiomyopathy (2/41). No specific diagnosis was made in the remainder and these were considered cryptogenic AMIʹs. At a mean follow-up of 44 ± 30 months, 1 patient with cryptogenic AMI had a non-cardiovascular death and 1 patient required pacing. In conclusion, there is a small but definite incidence of angiographically normal coronary arteries in patients presenting with STEMI. While the eventual aetiology remains uncertain in most patients, long-term outcomes appear favourable.