Door-to-balloon time and factors associated with delayed door-to-balloon time in ST-segment elevation myocardial infarction at Thailand's largest tertiary referral centre.

OBJECTIVE: To analyse door-to-balloon (DTB) time and to identify factors significantly associated with delayed DTB in patients with ST-segment elevation myocardial infarction (STEMI) at Thailand's largest tertiary referral centre.

BACKGROUND: DTB time is considered an important measure of performance quality.

METHODS: This observational study analysed DTB time in patients with STEMI who presented to our institute's emergency department and underwent primary percutaneous coronary intervention (PCI) during June 2008 to May 2011. DTB time greater than 90 minutes was considered delayed. Data were collected to determine which clinical variables were associated with delays.

RESULTS: One hundred thirty-three patients were included. The mean age of patients was 61.1 ± 13.2 years, and 71.4% were male. Delayed DTB was observed in 70.7% of patients. Median DTB time was 117 (interquartile range [IQR], 86-168), 66 (IQR, 58-84), and 135 (IQR, 112-194) minutes in all patients, in nondelayed patients, and in delayed patients, respectively. Univariate analysis revealed triage to urgent care (P = 0.001) and presentation during on-call hours (P < 0.001) to be significantly associated with delayed DTB. Patients who were triaged to urgent care had a DTB time of 184 vs 105 minutes for triage to the emergency room. Patients who presented during on-call hours had a DTB time of 128 vs 86 minutes for work hour presentation. Presentation during on-call hours was the only significant predictor of DTB time >90 minutes in multivariate analysis (odds ratio [OR], 7.86; 95% confidence interval [CI], 3.39-18.22; P < 0.001). All patients that were triaged to urgent care were delayed; thus, association between urgent care triage and on-call hour service could not be determined.

CONCLUSIONS: Delayed DTB time occurred in 70.7% of patients. Two key factors that significantly contributed to delayed DTB were patient mistriage to urgent care and presentation during on-call hours.