Abstract 4192: Community-Based Fire Department Ambulance Protocol Reduces Door-to-Balloon Times in ST-Elevation Myocardial Infarction
Background: Reduced door-to-balloon time (DBT) in primary PCI for the treatment of STEMI has been shown to improve outcomes. The Fire Department of NYC (FDNY) ambulance organization in 2007 implemented a city-wide system designed to track STEMI patients who presented for primary PCI. New York Presbyterian Hospital and Cornell Medical College implemented the FDNY guidelines in October 2007, including pre-hospital EKG transmission, into our protocol. This study analyzes all STEMI cases before and after the FDNY community-based protocol and attempts to determine if this mandatory reporting system led to a decrease in DTB times and whether this DBT improvement led to a reduction in myocardial necrosis as measured by creatine kinase - MB (CKMB) levels.
Methods: We analyzed 189 consecutive patients who presented emergently to our cardiac cath lab with STEMI and underwent primary PCI before and after the initiation of the FDNY protocol. DTB was strictly defined as emergency room nursing triage to intra-coronary device time. Serial, timed CKMB levels were obtained on all patients and plot-fitted, and the area-under-curve (AUC) was integrated and measured. We used a curve estimation regression model using the natural logarithm (ln) of AUC [CKMB] (considered to best correlate of total CKMB enzyme released) to evaluate the effect of DBT on myocardial cell death. Angiographic and clinical variables, including TIMI STEMI score, were measured on all patients.
Results: Patient variables were similar across the time periods. There was a significant decrease in mean DBT following the FDNY protocol initiation (78 vs. 95 minutes, p<0.01). Moreover, within the entire population, there was a significant correlation of ln AUC [CKMB] with respect to DBT (r=0.2, p=0.02). Using a propensity score analysis with multiple linear regression including TIMI STEMI score, DBT remained a significant independent predictor of ln AUC [CKMB] (beta=0.15, p=0.03).
Conclusion: Our study demonstrates the efficacy of a community-based reporting system to decrease DBT in STEMI patients. Moreover, data from our institution confirms that DBT was independently predictive of CKMB levels and the improvement in DBT led to a decrease in myocardial necrosis.