P5522ST elevation myocardial infarction networks: relationship of hub-spoke distance with transfer time and clinical outcomes in rescue PCI

Abstract

Abstract Background In the establishment of ST elevation myocardial infarction (STEMI) systems of care, transfer times between primary care units (PCU) and the cardiac catheterization lab (CCL) are pillars to therapeutic success. Objective: To analyze the relationship between PCU-CCL distance with transport time and main clinical outcomes in STEMI patients (p) treated with pharmaco-invasive therapy (PIT) and referred for rescue PCI after failed fibrinolysis. Methods Between January 2010 and December 2018, of the 2241 patients who received tenecteplase in PCU inserted in a large city STEMI network, 801 (35.7%) evolved without reperfusion criteria after 90 minutes (persistence of chest pain, less than 50% reduction on ST elevation or hemodynamic instability), being urgently transferred to the CCL. The PCU were divided according to the distance to the tertiary center in Group 1: between 5 and 9km (N=208p), Group 2: between 16 and 18km (N=315p) and Group 3: between 22 and 30km=266p). Considering an alpha of 0.05, sample size n=801 and an effect size of 0.11, a power of 0.80 was obtained. Results The groups were comparable for baseline features (Table 1). Group 2 (intermediate distances) had the highest median transport time (G1 260 interquartile 145–437 min vs G2 355 interquartile 206–573 min vs G3 241 interquartile 125–418 min; p<0.01 for G2). There were no differences between the groups regarding cardiogenic shock (G1 24.5% vs G2 23.3% vs G3 24.1%, p=0.9) or in-hospital death (G1 17.4% vs G2 12.3% vs G3 13.0%, p=0.2). Table 1. Group's baseline features G1: Short distances G2: Intermediate distances G3: Long distances p value (5–9 km) N=208 (16–18 km) N=315 (22–30 km) N=266 Age (median) 57.5 (51–64) 57 (49–66) 59 (52–67) 0.27 Female 29.7% 28.3% 35.1% 0.19 Hypertension 67.3% 60.9% 64.4% 0.31 Diabetes 37.0% 32.1% 37.8% 0.30 Renal failure 10.3% 9.7% 6.3% 0.21 Anterior STEMI 56.1% 58.4% 62.4% 0.36 Pain-to-needle time (median min) 197.5 (137–330) 195 (120–295) 195 (125–345) 0.38 Conclusion In STEMI patients with failed fibrinolysis treated with pharmaco-invasive therapy, the PCU-CCL distance was not related to transfer time or to outcomes of in-hospital death and cardiogenic shock. The longer transport time of hospitals located at intermediate distance can possibly reflect local logistical difficulties and are not due to hub-spoke distance. Continuous improvement in structuring and coordination of public STEMI networks is aimed.