Patient and Hospital Factors Predicting Prolonged Door-to-Balloon Time in STEMI Patients Undergoing Primary PCI

Background: Reducing delay to reperfusion with primary percutaneous coronary intervention (PPCI) is critical to improving systems of care for patients with ST-elevation myocardial infarction (STEMI). We sought to examine patient and hospital factors that predict prolonged door-to-balloon time (DTBT) in PPCI. Methods: We prospectively collected data on 2,827 consecutive PPCI patients between 2013 and 2015 in the multi-centre Victorian Cardiac Outcomes Registry and divided them by whether DTBT was prolonged (>90 minutes). Patients transferred from another hospital for PPCI and inpatient STEMIs were excluded. Results: 858 (30.4%) patients had prolonged DTBT. Most of the delay occurred prior to cardiac catheterisation laboratory arrival with only 9.9% achieving a door-to-laboratory time ≤60 minutes, compared to 92.7% in the DTBT ≤90 minutes group (p < 0.01). Median door-to-laboratory time was 3 times longer in the prolonged DTBT group (94 minutes [IQR 74-135] vs. 31 minutes [IQR 17-47], p < 0.01). 237 (21.2%) of the in-hours and 621 (36.3%) of the out-of-hours PPCI patients did not meet the DTBT ≤90 minutes target. Hospital-level prolonged DTBT rates ranged from 11.8% to 51.9%. Independent predictors of prolonged DTBT were age, history of previous PCI, absence of pre-hospital notification, cardiogenic shock/cardiac arrest and out-of-hours presentation (all p≤0.01). Prolonged DTBT was not an independent predictor of 30-day mortality in our cohort (p = NS). Conclusion: Nearly a third of STEMI PPCI patients do not meet the guideline-directed target of DTBT ≤90 minutes. Systems of STEMI care incorporating pre-hospital and in-hospital measures require further improvement to ensure DTBT hospital and operator targets are met.