Variability in Maximal Suggested Door‐in‐Door‐out Time for Hospitals Transferring Patients for Primary Angioplasty in STEMI

Objectives

We derived a formula for maximal suggested door‐in‐door‐out time (DIDO) for hospitals that do not perform primary percutaneous coronary intervention (PCI) for ST‐elevation myocardial infarction (STEMI).

Background

Efforts to minimize DIDO at non‐PCI hospitals can improve door‐to‐balloon time (D2B). Targeting a maximal suggested DIDO for a transferring hospital can influence reperfusion strategy.

Methods

We examined time to treatment intervals for 193 STEMI patients who underwent primary PCI at our hospital. D2B in transferred patients (D2B_T) was divided into 3 intervals: transferring hospital DIDO, inter‐hospital transport time, and interventional time. We defined maximal suggested DIDO as the maximum DIDO that would allow PCI with D2B_T ≤120 minutes.

Results

D2B was higher in transfer compared to on‐site patients (147 ± 52 vs. 75 ± 44 minutes, P < 0.0001). In transfer patients, treatment time intervals were: DIDO 80 ± 42 minutes, transport time 37 ± 18 minutes, interventional time 35 ± 16 minutes. The greatest variability in D2B_T was related to DIDO. We estimated that maximal suggested DIDO = 120 ? (transport time plus interventional time)]. Using a fixed interventional time of 40 minutes, we simplified this as: maximal DIDO = 80 ? transport time. Maximal suggested DIDO for 4 transferring hospitals in our network ranged from 1 to 65 minutes. DIDO under the hospital‐specific threshold was the strongest predictor of achieving D2B_T <120 minutes.

Conclusions

Transferring hospitals' maximal suggested DIDO is variable, and can be calculated from inter‐hospital transport time. Instead of a universal target DIDO (e.g., <30 minutes), maximal suggested DIDO can be calculated individually for each non‐PCI hospital within a STEMI network.