Table 4.

Summary of clinical studies investigating onset of symptoms and circadian variation of MI size in STEMI.

Studies	Country/years	Patients in study	Surrogate for MI size	Outcome
Suarez-Barrientos [1]	Single centre — Spain	811	CK TnI	Peak MI size between 06:00 and noon
Reiter [3]	Single centre — United States	165	CK	Peak MI size 01:00 onset of ischemia and 05:00 onset of reperfusion
Arroyo-Ucar [20]	Single centre — Spain	108	TnI	Peak MI size between 00:00 and 12:00
Fournier [4]	Single centre — Switzerland	353	CK	Peak MI size between 00:00 and 05:59.
Ammirati [19]	Multicentre — Italy, Scotland, and China	1099	CK	Peak MI incidence from 06:00 to noon. No clear-cut circadian dependence of MI size
Fournier [2]	Multicentre — Switzerland	6223	CK	Peak MI size at 23:00, whereas the nadir MI size was at 11:00. Risk of death from STEMI was the highest at 00:00 and lowest at 12:00
Seneviratna [6]	Multicentre — Singapore	6710	CK	Peak MI size and incidence of acute heart failure from midnight to 06:00 and nadir from 06:00 to noon
Mahmoud [7]	Multicentre — Netherlands	6799	CK	Peak MI size around 03:00 and nadir around 11:00
Ari [5]	Single centre — Turkey	252	CK-MB	Peak MI size and poor LV function by echocardiography occurred in the 06:00–noon period

CK: creatine kinase; TnI: troponin I; CK-MB: creatine kinase-myocardial band; MI: myocardial infarction; LV: left ventricle.