Most hospitals that perform primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) in the United States exceed the recommended door-to-balloon time. There is heightened interest in identifying and eliminating factors that introduce delay.

We performed a key process analysis of our primary PCI program, assessed the relative contribution of individual time intervals on total ischemic time, and identified predictors of delay.

Median times and predictors of delay within each time interval were determined for the entire STEMI cohort (“real world”) and after exclusion of patients with atypical symptoms and/or presentations of STEMI that resulted in inherent delay in diagnosis and treatment (“ideal world”). Delays in therapy were symptom onset to presentation (120 minutes [interquartile range, IQR, 60-310 minutes, ideal world] and 150 minutes [IQR 60-360 minutes, real world]; predictors of delay were peripheral vascular disease, self-transportation, daytime and weekend presentation); door-to-balloon time (118.5 minutes [IQR 96-141 minutes, ideal world] and 125 minutes [IQR 100-170 minutes, real world]; predictors of delay were female sex, previous stroke, nighttime and weekend presentation, and cardiogenic shock); and symptom onset to first balloon inflation (272 minutes [IQR 187-465 minutes, ideal world] and 297 minutes [IQR 198-560 minutes, real world]; predictors of delay were peripheral vascular disease, weekend presentation, and self-transportation).

Key process analysis of a primary PCI program identifies treatment delays unique to the hospital and the patient population it serves.