Aborted infarction: The ultimate myocardial salvage Lauren Dowdy, BA, a Galen S. Wagner, MD, a Yochai Birnbaum, MD, b Peter Clemmensen, MD, PhD, g Yuling Fu, MD, c Charles Maynard, PhD, d Ian Menown, MD, MRCP, e Maria Sejersten, MD, a Dwayne Young, BS, REMTP, f and Per Johanson, MD, PhD a Durham and Greensboro, NC, Galveston, Tex, Alberta and Vancouver, British Columbia, Canada, Seattle, Wash, and Copenhagen, Denmark See related article on page 509. The study reported by Lamfers et al 1 in this issue of the Journal raises our expectations for the outcome of reperfusion treatment of acute myocardial infarction. They observed minimal if any myocardial infarction (MI), termed “aborted infarction,” in almost one fifth of patients treated with prehospital intravenous fi- brinolytic therapy; 16.8% of prehospital-treated pa- tients met criteria for “aborted MI” compared with 4.5% treated only in hospital. The site of the triage decision was out of hospital in the Rotterdam and Ni- jmegen “intervention” centers and in the hospital Emergency Department in the Arnhem “control” cen- ter. Time is a crucial factor influencing the chance of ST elevation evolving into an aborted infarction. 2 A com- prehensive community program, including reduction in patient delay in combination with rapid triage and treatment, can increase the proportion of patients treated within sufficient time from onset of acute oc- clusion to achieve maximal myocardial salvage. 3 Movement of both triage and intravenous reperfu- sion, or triage alone for intracoronary therapy, from hospital to prehospital, is required for potential achievement of “aborted infarction.” Prehospital triage facilitates patient bypass of obstacles along the way to the already alerted cardiac catheterization laboratory to allow earlier percutaneous coronary intervention (PCI). Wall et al 4 reported a 27% (109 – 80 minutes) reduc- tion of time from hospital arrival to primary PCI by using prehospital ECG transmission to the emergency department (ED) in the TIME trial. With primary PCI, TIMI-3 coronary flow is achieved in 90% of the pa- tients regardless of time to treatment. 5 However, achievement of significant myocardial salvage has been demonstrated only when the mean time from symp- tom onset is within 2 hours. 6 Aggressive triage of pa- tients beginning with the initial contact with prehospi- tal care providers is critical to achieve significant time reduction and to salvage cardiac muscle. The Myocardial Infarction Triage and Intervention trial (MITI) used prehospital triage for either prehospi- tal or ED administration of thrombolytic therapy. There were comprehensive aspects including use of specially trained paramedics, a checklist to establish eligibility for and contraindications to thrombolytic therapy, and a portable, battery-powered 12-lead elec- trocardiographic cellular telephone system that al- lowed an electrocardiographic diagnosis to be made remotely by an ED physician. 7 A remarkable finding of the MITI trial was that 40% of all patients treated within 3 hours of symptom on- set had no evidence of infarction, as measured by thal- lium scanning at a median of 30 days after random as- signment. Minimal infarct sizes of 10% were noted in an additional 35% of patients. The authors concluded that “if patients can be identified and treated very early after symptom onset, the infarction process can be essentially aborted.” 8 In the MITI trial, the key pre- dictor of “aborted infarction” (by this definition) was the early treatment achieved through prehospital tri- age, and not whether therapy was delivered in the emergency vehicle or the hospital. New electrocardiographic triage decision support Patients present after varying delay intervals after acute thrombotic occlusion, and the speed of necrosis varies according to the level of protection by either collaterals or ischemic preconditioning. 9,10 New elec- trocardiographic algorithms have been developed to estimate both the acuteness of the process and the level of protection to provide support for the reperfu- sion triage decision for patients with ST-segment eleva- tion MI (STEMI). Since many patients do not have a definitive time of symptom onset, the Anderson-Wilkins acuteness score From a Duke Clinical Research Institute, Durham, NC, the b Division of Cardiology, The University of Texas Medical Branch, Galveston, Tex the c University of Alberta, Alberta, British Columbia, Canada, the d University of Washington, Department of Health Ser- vices, Seattle, Wash, e Cardiac Catheterization Laboratories, Vancouver Hospital and Health Sciences Centre, Vancouver, British Columbia, Canada, f Guilford County EMS, Greensboro, NC and g Rigshospitalet, University of Copenhagen, Copenhagen, Den- mark. Reprint requests: Galen S. Wagner, MD, Duke University Medical Center, 2400 Pratt St, Suite 0306, Durham, NC 27705. E-mail: wagne004@mc.duke.edu Am Heart J 2004;147:390 – 4. 0002-8703/$ - see front matter © 2004, Elsevier Inc. All rights reserved. doi:10.1016/j.ahj.2003.10.008 Editorial