Acute reperfusion for ST-elevation myocardial infarction in New Zealand (2015-2017): patient and system delay (ANZACS-QI 29)

Abstract

Aim: Prompt access to cardiac defibrillation and reperfusion therapy improves outcomes in patients with ST-segment elevation myocardial infarction (STEMI). The study aim was to describe the 'patient' and 'system' delay in patients who receive acute reperfusion therapy for ST-elevation myocardial infarction (STEMI) in New Zealand.

Methods: In 2015-17, 3,857 patients who received acute reperfusion therapy were captured in the All New Zealand Acute Coronary Syndrome Quality Improvement (ANZACS-QI) registry. 'Patient delay' is the time from symptom onset to first medical contact (FMC), and 'system delay' the time from FMC until reperfusion therapy (primary percutaneous coronary intervention (PCI) or fibrinolysis).

Results: Seventy percent of patients received primary PCI and 30% fibrinolysis. Of those receiving fibrinolysis, 122 (10.5%) received pre-hospital fibrinolysis. Seventy-seven percent were transported to hospital by ambulance. After adjustment, people who were older, male and presented to a hospital without a routine primary PCI service were less likely to travel by ambulance. Patient delay: The median delay was 45 minutes for ambulance-transported patients and 97 minutes for those self-transported to hospital, with a quarter delayed by >2 hours and >3 hours, respectively. Delay >1 hour was more common in older patients, Māori and Indian patients and those self-transported to hospital. System delay: For ambulance-transported patients who received primary PCI, the median time was 119 minutes. For ambulance-transported patients who received fibrinolysis, the median system delay was 86 minutes, with Māori patients more often delayed than European/Other patients. For patients who received pre-hospital fibrinolysis the median delay was 46 minutes shorter. For the quarter of patients treated with rescue PCI after fibrinolysis, the median needle-to-rescue time was prolonged-four hours.

Conclusions: Nationwide implementation of the NZ STEMI pathway is needed to reduce system delays in delivery of primary PCI, fibrinolysis and rescue PCI. Ongoing initiatives are required to reduce barriers to calling the ambulance early after symptom onset.