Periodic variation and its effect on management and prognosis of Korean patients with acute myocardial infarction.
BACKGROUND
The characteristics of the periodic variation in acute myocardial infarction (AMI) and the subsequent effect on management and prognosis have not been fully investigated in a large number of Asian populations.


RESULTS
From a prospective, observational multicenter online registry, 4,573 patients diagnosed as AMI in Korea from January to December 2006 were included. The highest incidence of AMI was between 8 a.m. and noon. The number of cases was highest in the winter and lowest in the autumn (13.6 vs 11.4 patients per day, P<0.001). Patients with symptom onset during working hours had a shorter time to first medical contact (203+/-288 min) compared with out-of-hours onset (230+/-288 min, P=0.003). In patients who underwent primary angioplasty, out-of hours symptom onset was associated with a greater time delay in both the patient's and the medical facility's response (door-to-balloon time out-of hours vs working hours: 101+/-54 min vs 84+/-44 min, P<0.001). In patients with ST-segment elevation myocardial infarction, symptoms to first medical contact showed a significant relationship to in-hospital mortality (for every 10 min of symptoms to first medical contact, odds ratio 1.006, 95% confidence interval 1.001-1.012, P=0.018)


CONCLUSIONS
Circadian and periodic variation in AMI exists in Korean patients, which resulted in different patient behavior, hospital management and outcomes.
Park
Hyo Eun
HE
Division of Cardiology, Department of Internal Medicine, College of Medicine, Seoul National University, Seoul, Korea.
Koo
Bon-Kwon
BK
Lee
Wonjae
W
Cho
Youngjin
Y
Park
Jin Sik
JS
Choi
Ji-Yong
JY
Jeong
Myung-Ho
MH
Kim
Jong Hyun
JH
Chae
Shung Chull
SC
Kim
Young Jo
YJ
Nam
Chang-Wook
CW
Lee
Jae-Hwan
JH
Choi
Dong Hoon
DH
Hong
Taek Jong
TJ
Chae
Jei Keon
JK
Rhew
Jae Young
JY
Kim
Kee Sik
KS
Kim
Hyo-Soo
HS
Oh
Byung-Hee
BH
Park
Young Bae
YB
D000368:Aged; D044466:Asian People; D002940:Circadian Rhythm; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000628:therapy; D011446:Prospective Studies; D012042:Registries; D056910:Republic of Korea / Q000453:epidemiology; D012621:Seasons; D013997:Time Factors