Objectives This study was conducted to break the door-to-balloon time (DTBT) into constituent elements, and compared which components prolonged markedly. We identified the factors that significantly prolonged the DTBT in an underdeveloped area of China.

Methods The patients were included from January 2008 to December 2010 in 301 consecutive patients presenting with STEMI in our hospital. We analysed the components of total DTB times, such as ‘Diagnosis time’, ‘Cardiologist consultation time’, ‘Explain the patient's condition time’, ‘Transferring time’, ‘Preparation of the catheterisation laboratory (CL) time’, and determined which factors significantly prolonged the DTBT potentially.

Results The median DTBT of all patients was 134 (98–186) min. The group was divided by the DTBT into two: ≤120 min and >120 min. In the ≤120 min group, more patients (68.1%) presented to our hospital during working hours (p=0.000), whereas in the >120 min group, more patients (63.2%) presented out of hours (p=0.000). More patients (49.3%) presented when the interventionist was on site (p=0.000) in the ≤120 min group. In the >120 min group, the times for consultation by the cardiologist and explaining the patient's condition to the family prolonged markedly, as compared to the ≤120 min group (p=0.000) when the interventionist was off-duty (OR=4.050, p=0.000) and presentation during non-working hours (OR=3.334, p=0.000) were significant predictors of >120 min DTB times.

Conclusions In our centre, the time of consultation by the cardiologists and explaining the patient's condition to the family accounted for most of the delay in reperfusion. A lack of interventionists usually resulted in a delay during non-working hours in the CL. Several measures should be taken involving asking emergency department physicians to awake CL directly, sending the patients’ information to the cardiologists, popularising medical knowledge to the citizens, and increasing the numbers of interventionists qualified to carry out primary percutaneous coronary intervention, should be developed to shorten the DTBT.