Centralised Management System and Hot Transfer for ST-Elevation Myocardial Infarction in Western NSW: Closing the Gap in Current Models of Rural ST-Elevation Myocardial Infarction Care.

Abstract

Background: Rural vs metropolitan ST-elevation myocardial infarction (STEMI) patients experience delayed access to percutaneous coronary intervention (PCI). Existing New South Wales (NSW) Statewide Cardiac Reperfusion Strategy protocols provide thrombolysis and ambulance diversion for patients within 90 minutes of a PCI centre in regional and rural NSW. Rural patients presenting to non-PCI hospitals and those more than 90 minutes from PCI are not routinely, urgently, diverted under existing protocols.

Method: Western NSW Local Health District, covering 250,000 km² and a population of 278,759, implemented a centralised management system (CMS) in 2019, in partnership with NSW Ambulance, utilising existing STEMI thrombolysis protocols and extending "drip and ship" protocols for "hot transfer" of all patients to the 24/7 PCI centre, by direct ambulance diversion up to 120 minutes by road, or via multi-stage transfer by road or air, or via interhospital transfer. Data for 2 years post-CMS was compared to historical controls. Time from first clinical contact (FCC) to reperfusion, FCC to PCI centre, major adverse clinical events and percentage of patients undergoing angiography within 24 hours were compared in "medium" (90-120 minutes) and "long" (>120 minutes) transfer zones, not covered by existing protocols.

Results: Outcomes were recorded for 274 patients before and 348 after CMS implementation (17% medium and 31% long transfer zones). Medium and long transfer zones had greater proportions of smokers and Indigenous patients than short transfer zones. There was significantly lower ambulance utilisation in the long (38%) compared with the short transfer zone (55%, p<0.001). In the long transfer zone, there were significant improvements in FCC to reperfusion (40 vs 48 minutes, p<0.05), FCC to PCI centre (296 vs 344 minutes, p<0.01), and angiography in 24 hours (77% vs 58%, p<0.01), with no significant differences in major adverse clinical events.

Conclusions: A rural STEMI CMS, with "hot transfer", can deliver patients from a vast geographical area directly to a rural PCI centre. Patients furthest away, with the greatest risk profile, benefit the most. Extension of this program and development of 24/7 PCI in NSW rural cardiac hubs stands to improve timely, definitive treatment, including access to angiography within 24 hours.