Objective To identify patients with type 2 myocardial infarction (MI) and patients with non-ischaemic myocardial injury (NIMI) and to compare their prognosis with those of patients with type 1 MI.
Methods A retrospective observational study was performed in 1010 patients admitted to the emergency department of a university hospital with at least one troponin I test between 2012 and 2013. Participants were identified using laboratory records and divided into three groups: type 1 MI (rupture of atheromatous plaque), type 2 MI (imbalance between myocardial oxygen supply and/or demand) and NIMI (patients who did not meet diagnostic criteria for type 1 or type 2 MI). Clinical characteristics and 2-year outcomes were analysed.
Results Patients with type 2 MI and NIMI were older, with higher proportion of women and more comorbidities than patients with type 1 MI. Absolute mortality and the adjusted risk for all-cause mortality in both groups were significantly higher than that of patients with type 1 MI (39.7%, HR: 1.41 95% CI 1.02 to 1.94, p=0.038 and 40.0%, HR: 1.54 95% CI 1.16 to 2.04, p=0.002, respectively). Patients with type 2 MI and NIMI tended to present more readmissions due to heart failure (16.5%, HR: 1.55 95% CI 0.87 to 2.76, p=0.133 and 12.3%, HR: 1.15 95% CI 0.70 to 1.90, p=0.580) and less readmission rates due to acute coronary syndrome (ACS) than patients with type 1 MI (2.1%, HR: 0.11 95% CI 0.04 to 0.31, p<0.001 and 4.3%, HR: 0.22 95% CI 0.12 to 0.41, p<0.001),
Conclusions Patients diagnosed with type 2 MI and NIMI have higher rates of mortality and lower readmission rates for ACS compared with patients with type 1 MI.
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Twitter Follow Germán Cediel at @GermanECediel
Contributors All authors contributed significantly to the work. GC and AB conceived the study. Statistical analysis was carried out by GC. AB supervised data analyses. The manuscript was drafted by GC and AB. MG-d-H, AC, RS and CB revised it critically for intellectual content. All authors provided final approval of the manuscript.
Competing interests None declared.
Ethics approval Local ethical committee (Comité Ético de Investigación Clínica – CEIC).
Provenance and peer review Not commissioned; externally peer reviewed.
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