Symptom-to-door delay among patients with ST-segment elevation myocardial infarction in Singapore

Objectives: Symptom-to-door time (S2D) is one of the important components of ischaemic time, which might affect the infarct size and outcomes of acute myocardial infarction. The aim of the present study was to identify patients' characteristics associated with delayed symptom-onset-to-arrival at EDs in ST-segment elevation myocardial infarction (STEMI) patients in Singapore.

Methods: Retrospective data of STEMI patients presenting to the ED of all public hospitals with onsite primary percutaneous coronary intervention facilities between 2010 and 2012 were obtained from the Singapore Myocardial Infarction Registry. Based on the S2D of 120 min, characteristics of patients were compared between short S2D (≤120 min) and long S2D (>120 min). Multivariate logistic and linear regression analyses were performed.

Results: Out of 3848 patients, 1682 patients had an S2D of ≤120 min, and 2166 had an S2D >120 min. In the multivariate analyses, older age, Malay ethnicity, diabetes mellitus, presenting symptoms of back and epigastric pain were independently associated with long S2D. Patients who utilised the emergency medical services, presented after office hours and with symptoms of chest pain, breathlessness, diaphoresis and past history of percutaneous transluminal coronary angioplasty/primary percutaneous coronary intervention, were independently associated with short S2D. Patients with long S2D had lower probability of receiving reperfusion treatment with delayed symptom-to-balloon and door-to-balloon time and higher probabilities of complications and mortality.

Conclusion: The present study shows that longer S2D was associated with older age, ethnicity, diabetes mellitus, delay in receiving early reperfusion treatment and poorer prognosis.