Reperfusion treatment delays amongst patients with painless ST segment elevation myocardial infarction.
OBJECTIVE
Early reperfusion therapy in the treatment of ST segment elevation myocardial infarction (STEMI) patients can improve outcomes. Silent myocardial infarction is associated with poor prognosis, but little is known about its effect on treatment delays. We aimed to characterize STEMI patients presenting without complaints of pain to the emergency departments (EDs) in Singapore.


METHODS
Retrospective data were requested from the Singapore Myocardial Infarction Registry (SMIR), a national level registry in Singapore. Painless STEMI was defined as the absence of pain (chest, back, shoulder, jaw, and epigastric pain) during ED presentation. The primary outcome was door-to-balloon (D2B) time, defined as the earliest time a patient arrived in the ED to balloon inflation. Secondary outcomes were 1-month and 1-year mortality and occurrence of adverse events.


RESULTS
From January 2010 to December 2012, the SMIR collected 6412 cases; 10.9% of patients presented without any pain. These patients were older (median age =75 v. 58 years old), more likely to be females (39.9% v. 16.1%), Chinese (74.9% v. 62.7%), obese (median body mass index [BMI] =24.5 v. 22.1), and with history of hypertension (71.1% v. 54.6%), diabetes mellitus (48.6% v. 37.0%), and acute myocardial infarction (20.0% v. 12.3%). They had a longer median D2B (80.5 v. 63 minutes, p<0.001) and a higher occurrence of 30-day (38.4% v. 5.7%) and 1-year mortality rates (47.3% v. 8.5%).


CONCLUSIONS
A small proportion of STEMI patients presented without any pain to the ED. They tended to have a higher D2B and risks of mortality. Targeted effort is required to improve diagnostic and treatment efficiency in this group.
*Department of Emergency Medicine,Singapore General Hospital,Singapore.
Pin Pin
PP
Pek
‡National Registry of Diseases Office,Health Promotion Board,Singapore.
En Yun
EY
Loy
§Centre for Infectious Disease Epidemiology and Research,Saw Swee Hock School of Public Health,Tahir Foundation Building,National University of Singapore,Singapore.
Win
W
Wah
¶Emergency Medicine Residency Program,SingHealth Services,Singapore.
Andrew Fu Wah
AFW
Ho
‡National Registry of Diseases Office,Health Promotion Board,Singapore.
Huili
H
Zheng
†Division of Research,Singapore General Hospital,Singapore.
Stephanie Man Chung
SMC
Fook-Chong
**Department of Cardiology,National Heart Centre,Singapore.
Terrance Siang Jin
TSJ
Chua
**Department of Cardiology,National Heart Centre,Singapore.
Tian Hai
TH
Koh
**Department of Cardiology,National Heart Centre,Singapore.
Khuan Yew
KY
Chow
*Department of Emergency Medicine,Singapore General Hospital,Singapore.
Nan
N
Liu
*Department of Emergency Medicine,Singapore General Hospital,Singapore.
Marcus Eng Hock
MEH
Ong
D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000379:methods* / Q000401:mortality*; D015331:Cohort Studies; D016001:Confidence Intervals; D016208:Databases, Factual; D004562:Electrocardiography / Q000379:methods; D004632:Emergency Medical Services / Q000379:methods; D004636:Emergency Service, Hospital; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010147:Pain Measurement; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D000072657:ST Elevation Myocardial Infarction / Q000000981:diagnostic imaging / Q000401:mortality* / Q000628:therapy*; D012720:Severity of Illness Index; D012846:Singapore; D015996:Survival Rate; D016896:Treatment Outcome
door-to-balloon; mortality; myocardial infarction; painless STEMI; registry