The Tyranny of Distance: Emergency Regional Transfers for STEMI

Abstract

Aim: We aimed to characterise regional center emergency catheterisation referrals for ST elevationmyocardial infarction (STEMI) or cardiac arrest (CA). Methods: A single institution prospective database of STEMI/CA patients was interrogated to identify these patients and descriptive statistics derived. Findings: Sixty-five (65) patients were identified (2008 to February 2012). The following baseline characteristics were present: age 60± 13 years (mean± standard deviation), 82% male, 66% post-fibrinolysis, 7% CA, and 15% shocked. Percutaneous intervention (PCI) was performed in 89% (success 98%). Balloonpumpswereused in 9%.Two patients received urgent bypass surgery. One patient had the final diagnosis not STEMI. The hospital mortality was: 7.7%. The median distance from the institution of referring site was 138 (72,240) km with range 6–597 km. A map is shown below (point size scaled to referral number). The average time from onset of symptoms to cath lab arrival (CLA) was 5.8 h. This time was correlated with distance (p< 0.05). It explained only 19% of the variation. The day of week and time of day of CLA are shown in the second viously been assessed in the era of primary percutaneous coronary intervention (PCI). We sought to determine the validity of the TRS in both male and female ST Elevation Myocardial Infarction (STEMI) patients who have undergone early field triage. Methods: This was a single centre retrospective cohort study identifying consecutive STEMI patients presenting for primary-PCI via field triage between May 2004 and December 2010. Unpaired t-tests were used to determine significant demographic differences in males and females. Linear regression analysis was used to determine the correlation of the TRS with the endpoints of 30 day majoradverse cardiacevents (MACE)andmedianhospital length of stay (LOS). Results: 329 patients presented with STEMI via field triage, of which 248 (75.4%)weremale and 81 (24.6%)were female. Women were more likely to be older (73.2 vs 68.2, p< 0.0001), hypertensive (60.5% vs 44.9%, p< 0.05), show signsofpulmonaryoedemaatpresentation (17.5%vs7.6%, p< 0.05) andhaveahigherTRS (4.90 vs 3.14,p< 0.0001). The TRS was predictive of MACE (R2 = 0.57, p< 0.02) and hospital LOS (R2 = 0.79, p< 0.001) in the entire cohort. The TRS was found to be predictive of MACE and hospital LOS in males (R2 = 0.57, p< 0.02; R2 = 0.87, p< 0.0001 respectively) as well as females (R2 = 0.58, p< 0.02; R2 = 0.66, p< 0.02 respectively). Conclusion: The TRS is a useful prognostic tool in