The impact on long term health outcomes for STEMI patients during a period of process change to reduce door to balloon time

Guidelines for the management of ST-segment elevation myocardial infarction (STEMI) recommend a ‘door to balloon time’ (DTBT) within 90 minutes. It is unclear whether strategies to reduce DTBT translate to improved longer-term health outcomes for STEMI patients.

This study sought to determine whether implemented strategies to improve timely management of STEMI reduced DTBT and impacted upon health outcomes such as length of stay, unplanned readmission and 12-month mortality. Predictors of timely management for STEMI were also examined.

A five-year review was undertaken on primary percutaneous coronary intervention for STEMI in one tertiary hospital. Comparisons were made between process change groups and DTBT. Logistic regression identified predictors of timely management.

470 STEMI patients underwent immediate primary percutaneous coronary intervention. Process change improved the median DTBT (109 min vs. 72 min, p<0.001) with no significant effect on length of stay (p=0.83), unplanned cardiac readmissions (p=0.68) or 12-month mortality (9.0% vs. 8.6%, p=0.64). Those receiving timely treatment (i.e. DTBT< 90 min) were younger (p<0.05), male (p<0.03), presented via ambulance (p<0.004), during business hours (p<0.0001) and had a lower Thrombolysis In Myocardial Infarction score (p<0.006). Timely treatment was associated with lower 12-month mortality (3.7% vs. 15.7%, p<0.0001) and increased uptake of inpatient cardiac rehabilitation (p<0.005), with length of stay and unplanned readmission similar between groups (p=NS).

Process changes improved DTBT but had no effect on length of stay, readmission rate or 12-month mortality. Yet, timely management was critical to 12-month outcomes. Further studies are required to explore the barriers to timely treatment.