Impact of Door-to-Balloon Time in Patients With ST-Elevation Myocardial Infarction Who Arrived by Self-Transport　― Acute Myocardial Infarction-Kyoto Multi-Center Risk Study Group ―

Abstract

Background:Patients with ST-elevation myocardial infarction (STEMI) who arrive at a hospital via self-transport reportedly have a delayed door-to-balloon time (DBT). However, the clinical impacts of delayed DBT on in-hospital mortality among such patients are not well known.

Methods and Results:In total, 1,172 STEMI patients who underwent primary percutaneous coronary intervention between January 2009 and December 2013 from the Acute Myocardial Infarction (AMI) Kyoto Registry were analyzed. Compared with the emergency medical service (EMS) group (n=804), the self-transport group (n=368) was younger and had a significantly longer DBT (115 min vs. 90 min, P<0.01), with fewer patients having a Killip classification of 2 or higher. The in-hospital mortality rate was lower in the self-transport group than in the EMS group (3.3% vs. 7.1%, P<0.01). A DBT >90 min was an independent predictor of in-hospital mortality in EMS patients (odds ratio (OR)=2.43, P=0.01) but not in self-transport patients (OR=0.89, P=0.87).

Conclusions:The present study demonstrated that there was no relationship between in-hospital prognosis and DBT ≤90 min in STEMI patients using self-transport. The prognosis of these patients cannot be improved by focusing only on DBT. Treatment strategies based on means of transport should also be considered.