Symptom-to-Balloon Time is a Strong Predictor of Adverse Events Following Primary Percutaneous Coronary Intervention: Results From the Australian Capital Territory PCI Registry

Abstract

Background: Notwithstanding improvements in door-to-balloon time, adverse event rates after primary PCI have remained steady. We analysed the effect of symptom-to-balloon (STB) time, a reflection of total ischaemic time, on major adverse cardiovascular events (MACE) and explored predictors of prolonged STB time.

Methods: The study population included 1002 consecutive patients (22.4% women) with a mean age of 62.3±13.2 years, who underwent primary PCI during 2008-2014. Groups were compared for STB ≤ and >240min. Primary endpoint was one-year MACE, a composite of death, reinfarction, stent thrombosis or target vessel revascularisation.

Results: Symptom-to-balloon time was available in 893 patients of which 588 (65.8%) had STB ≤240min and 305 (34.2%) had STB >240min. The incidence of one-year MACE increased significantly in a stepwise manner with increasing STB time (p for trend=0.003). Symptom-to-balloon time was an independent predictor of one-year MACE along with age >70 years, final TIMI flow <3, three vessel disease, cardiogenic shock and out-of-hospital cardiac arrest. We also performed a multivariate analysis to determine predictors of delayed treatment. Predictors of STB time >240min were age >70 years, female gender, diabetes, absence of prehospital catheter laboratory activation and presentation to a non-PCI centre.

Conclusion: Incidence of MACE was strongly correlated with STB time and STB time was an independent predictor of MACE. We have identified specific subgroups with prolonged STB times (age >70, female gender, diabetes, absence of prehospital activation and presentation to a non-PCI centre). This information should inform future studies and strategies to minimise delays in these subgroups for improved outcomes.

Keywords: Door-to-balloon time; Major adverse cardiovascular events; Primary PCI; ST elevation myocardial infarction; Symptom-to-balloon time; Time to treatment.