J Intern Med. 2021 Feb 12. doi: 10.1111/joim.13272. Online ahead of print.
BACKGROUND: Characteristics and prognosis of patients admitted with strong suspicion of myocardial infarction (MI) but discharged without an MI diagnosis are not well described.
OBJECTIVES: To compare background characteristics and cardiovascular outcomes in patients discharged with or without MI diagnosis.
METHODS: The DETermination of the role of Oxygen in suspected Acute Myocardial Infarction (DETO2X-AMI) trial compared 6629 patients with strong suspicion of MI randomized to oxygen or ambient air. The main composite endpoint of this subgroup analysis was the incidence of all-cause death, rehospitalization with MI, heart failure (HF), or stroke during a follow-up of 2.1 years (median; range 1-3.7 years) irrespective of randomized treatment.
RESULTS: 1619 (24%) received a non-MI discharge diagnosis, 5010 patients (76%) were diagnosed with MI. Groups were similar in age but non-MI patients were more commonly female and had more co-morbidities. At thirty days, the incidence of the composite endpoint was 2.8% (45 of 1619) in non-MI patients, compared to 5.0% (250 of 5010) in MI patients with lower incidences in all individual endpoints. However, for the long-term follow-up, the incidence of the composite endpoint increased in the non-MI patients to 17.7% (286 of 1619) as compared to 16.0% (804 of 5010) in MI patients, mainly driven by a higher incidence of all-cause death, stroke, and HF.
CONCLUSIONS: Patients admitted with a strong suspicion of MI but discharged with another diagnosis had more favorable outcomes in the short-term perspective but from one year onwards, cardiovascular outcomes and death deteriorated to a worse long-term prognosis.