Importance of delayed perfusion with primary angioplasty on short-term mortality in acute myocardial infarction patients.
BACKGROUND
Early primary coronary interventions (PCI) in acute ST elevation myocardial infarction (STEMI) is associated with improved outcome and mortality rate but delayed reperfusion especially after 6 hours is still doubtful in terms of clinical benefits because most myocardial muscle are infarcted after 6 hours of onset of chest pain.


OBJECTIVE
The aim of the present study was to compare the mortality rate of patients treated with PCI within 6 hours of symptom onset to those treated between 6 to 24 hours after the onset of STEMI.


METHODS
The present study included consecutive patients from the data of the Fast Track Registry of King Chulalongkorn Hospital from June 1, 1999 to October 31, 2003 to compare the thirty-day mortality of patients treated with early or delayed PCI (0-6 hours vs. 6-24 hours after symptom of chest pain) for STEMI.


RESULTS
Two hundred and sixteen patients who underwent PCI were enrolled. Male gender (82% vs. 64.9%, p = 0.03) and history of smoking (72.1% vs. 50%, p = 0.04) were predominant in the early treatment group (ETG) vs. the delayed treatment group (DTG). Mean age (60.5% vs. 61.03%, p = 0.11), diabetes (31.4% vs. 29.7%, p = 0.82), hypertension (64.0% vs. 54.1%, p = 0.20), dyslipidemia (58.1% vs. 60.8%, p = 0.73), and ejection fraction < 40% (22.8% vs. 32.0%, p = 0.625) were similar in both groups. There were no differences in angiographic finding and hospital management. Door to balloon and total delay time were 124.13 +/- 143.27 min and 407.94 +/- 268.183 min, respectively. The thirty-day mortality (9.01% vs. 12.76%, p = 0.379) and I year mortality (12.4% vs. 16 9%, p = 0.532) were not significantly determined by Log rank test in both groups. As for cardiogenic shock, ETG tended to have a lower thirty-day mortality than DTG but no statistically significant difference (12.5% vs. 50.0%, p = 0.0809).


CONCLUSIONS
The delayed PCI up to 24 hours in STEMI does not increase short-term mortality at thirty days; therefore, it may still have benefit in STEMI patients. However it tended to have higher short-term mortality than early PCI especially in cardiogenic shock but showed no statistical significance.
Kruthkul
Khanat
K
Division of Cardiovascular Disease, Department ofMedicine, King Chulalongkorn Memorial Hospital, Bangkok, Thailand.
Srimahachota
Suphot
S
Udayachalerm
Wasan
W
Budhari
Wacin
W
Charipromprasit
Jarkarun
J
Suitthichayakul
Taworn
T
Sitthi-amorn
Chitr
C
D000208:Acute Disease; D000800:Angioplasty, Balloon; D015906:Angioplasty, Balloon, Coronary; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D015425:Myocardial Reperfusion / Q000379:methods* / Q000401:mortality; D010477:Perfusion / Q000379:methods*; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome