Impact of Mode of Transportation On EMS-call-to-PCI Time and Door-to-Balloon Time in STEMI Patients: A Systemic Review and Meta-Analysis of 35,057 Patients

Introduction: Emergency revascularization with primary percutaneous coronary intervention (PCI), has been established to improve clinical outcomes for patients with acute coronary syndromes (ACS) and healthcare facilities allot and utilize resources to minimize delays to PCI and reduce door to balloon time. To our knowledge, this is the first meta-analysis that evaluates the data from these research studies collectively. The present meta-analysis focused on evaluating modalities for emergency transport systems and their impact on the outcomes of patients with STEMI.   Methods: We performed a comprehensive literature search for published studies indexed in PubMed, Embase, and Web of Science. This meta-analysis included a total of nine studies that met our inclusion criteria and had a total of 35,057 patients. All studies were observational in nature. Our primary outcomes of interest were the door to balloon time and EMS call to PCI time. Secondary outcomes evaluated were time from arrival at non-PCI facility to PCI within 90 minutes and within 120 minutes.   Results: The major findings for STEMI patients transported by air using helicopter compared with those transported by ground ambulance were as follows: first, EMS call to PCI was shorter in air transportation compared to ground transportation (mean difference -26.28; 95% CI -28.03- -24.52; P<0.001; I2=100%). Second, air transportation had a shorter time from door to balloon (mean difference -1.52; 95% CI -2.10 - -0.93; P<0.001; I2=12%). Third, when comparing air to ground transfer from non-PCI to PCI-capable facilities within the guideline recommended time windows of 90 minutes and 120 minutes for STEMI patients, transfer via air transportation was less likely to achieve the target timeline (within 90 minutes: OR 0.21; 95% CI, 0.05- 0.86; P=0.03; I2=52%; within 120 minutes: OR 0.63; 95% CI 0.59- 0.67; P<0.001; I2=64%).   Conclusion: Data included in this meta analysis show that air transport reduces EMS call to PCI time and door to balloon time for STEMI patients. However, for secondary transfer (from a non-PCI center to a PCI-capable center) air transportation was not superior for achieving guideline-recommended goal times. These results may have implications on transport protocols for STEMI patients. Mode of transportation should be individualized based on the distance from the PCI capable center, patient condition and the local environmental condition. Although thrombolytic therapy was mentioned in the introduction, it was not evaluated in this meta-analysis and remains an important consideration in remote or resource-limited settings.