[Influence of diurnal variation in the size of acute myocardial infarction].
ABSTRACT To evaluate whether the size of acute myocardial infarction (AMI) shows circadian variability.
An observational, prospective study.
A 12-bed coronary care unit.
Consecutive patients diagnosed with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention.
The patients were divided into two groups according to the time of onset of AMI symptoms (Group A: 0-12hours, Group B: 12-24hours).
Age, sex, cardiovascular risk factors, coronary anatomy, left ventricular ejection fraction, infarct location, time from onset of symptoms to reperfusion, presence of heart failure upon admission, and peak troponin I value.
A total of 108 patients with a diagnosis of STEMI were included. Patients in group A showed a higher troponin I concentration compared to group B (troponin I: 70.85±16.38 versus 60.90±22.92ng / ml, p=0.003). In the multivariate analysis the onset of AMI between 0-12hours was identified as an independent predictor of infarct size (OR: 1.133, 95%CI 1.012-1.267, p=0.01).
An onset of AMI between 0-12hours results in a significantly larger final size of necrosis compared with any other time of presentation.