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Circadian Variability and Its Influence on Infarct Size and Clinical Outcome Among Japanese Patients With Acute
Tetsufumi Motokawa1, Satoshi Honda2, Satoshi Ikeda1
1Department of Cardiovascular Medicine, Nagasaki University Graduate School of Biomedical Sciences Nagasaki Japan.
Insights
Circadian rhythms do not impact infarct size or clinical outcomes in patients with ST-elevation myocardial infarction (STEMI). This study found no significant differences in peak creatine kinase levels or mortality rates based on the time of myocardial infarction onset.
Area of Science:
- Cardiology
- Chronobiology
- Clinical Research
Background:
- Significant circadian variation exists in myocardial infarction (MI) onset, with a peak in the early morning.
- The influence of this circadian rhythm on post-acute myocardial infarction (AMI) clinical outcomes and infarct size remains unclear.
Purpose of the Study:
- To investigate whether circadian variation affects infarct size and clinical outcomes in patients with ST-elevation myocardial infarction (STEMI).
Main Methods:
- The study analyzed 2,251 patients with STEMI from the Japan AMI Registry (JAMIR).
- Patients were stratified into four time periods based on the documented time of MI onset.
- Peak creatine kinase (CK) levels were used as the primary indicator of infarct size, with in-hospital mortality and 1-year clinical outcomes as secondary endpoints.
Main Results:
- No significant differences in peak CK levels (indicating infarct size) were observed among the four time period groups.
- The time of MI onset did not significantly correlate with peak CK levels.
- Secondary endpoints, including in-hospital mortality, 1-year all-cause mortality, recurrent MI, stroke, stent thrombosis, and a composite endpoint, showed no significant differences across the time period groups.
Conclusions:
- Circadian variation does not appear to influence infarct size or clinical outcomes in patients experiencing STEMI.
Background:
There is significant circadian variation in the frequency of myocardial infarction onset, with a notable increase during the early morning. However, it remains unclear whether this circadian rhythm influences post-acute myocardial infarction (AMI) clinical outcomes and infarct size.
Methods And Results:
This study included 2,251 patients enrolled in the Japan AMI Registry (JAMIR) who had ST-elevation myocardial infarction (STEMI) with a documented time of onset, stratified into 4 time periods: 00:00-06:00, 06:00-12:00, 12:00-18:00, and 18:00-00:00 h. The primary outcome measure, used as an indicator of infarct size, was peak creatine kinase (CK) level. The median peak CK level among patients was 1,978 IU/L. No significant differences in peak CK levels were observed among the 4 time period groups (P=0.117). Similarly, the relationship between onset time and peak CK levels was not significant (P=0.215). There were no significant differences among the 4 time period groups in secondary endpoints of in-hospital mortality (P=0.788) and 1-year clinical outcomes, including all-cause mortality (P=0.544), myocardial infarction (P=0.636), stroke (P=0.943), stent thrombosis (P=0.344), and a composite endpoint (cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke; P=0.430).
Conclusions:
Circadian variation had no effect on infarct size or clinical outcomes in patients with STEMI.
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