Circadian variations of ischemic burden among patients with myocardial infarction undergoing primary percutaneous coronary intervention.
BACKGROUND
Several parameters of cardiovascular physiology and pathophysiology exhibit circadian rhythms. Recently, a relation between infarct size and the time of day at which it occurs has been suggested in experimental models of myocardial infarction. The aim of this study is to investigate whether circadian rhythms could cause differences in ischemic burden in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI).


METHODS
In 353 consecutive patients with STEMI treated by PPCI, time of symptom onset, peak creatine kinase (CK), and follow-up at 30 days were obtained. We divided 24 hours into 4 time groups based on time of symptom onset (00:00-05:59, 06:00-11:59, 12:00-17:59, and 18:00-23:59).


RESULTS
There was no difference between the groups regarding baseline patients and management's characteristics. At multivariable analysis, there was a statistically significant difference between peak CK levels among patients with symptom onset between 00:00 and 05:59 when compared with peak CK levels of patients with symptom onset in any other time group (mean increase 38.4%, P < .05). Thirty-day mortality for STEMI patients with symptom onset occurring between 00:00 and 05:59 was significantly higher than any other time group (P < .05).


CONCLUSIONS
This study demonstrates an independent correlation between the infarct size of STEMI patients treated by PPCI and the time of the day at which symptoms occurred. These results suggest that time of the day should be a critical issue to look at when assessing prognosis of patients with myocardial infarction.
Cardiology, University Hospital Center, Lausanne, Switzerland.
Stephane
S
Fournier
Eric
E
Eeckhout
Fabio
F
Mangiacapra
Catalina
C
Trana
Nathalie
N
Lauriers
Ahmed T
AT
Beggah
Pierre
P
Monney
Stephane
S
Cook
Daniel
D
Bardy
Pierre
P
Vogt
Olivier
O
Muller
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D002940:Circadian Rhythm / Q000502:physiology*; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000503:physiopathology*; D018450:Disease Progression; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors