1 To the Editor: We read with interest the article of Niccoli et al, 1 who demonstrated a significant in vivo eosinophil degranulation and basophils activation dur- ing acute coronary syndrome along with a prognostic role of eosinophil cationic protein in ST-segment–elevation myocardial infarction. Indeed, the interplay between ischemic heart disease and atopy/allergy is com- plex and not completely revealed to date because the first report of acute coronary syndrome during a prolonged allergic reaction to penicillin was published more than half a century ago, 2 followed by several studies sup- porting a role for allergic mediators in ischemic heart disease. 3 In 1998, Eugene Braunwald described that vasospastic angina may be triggered by allergic reactions with mediators, such as histamine or leukotrienes, acting on coronary vascular smooth muscle. 4 The results of Niccoli et al 1 are consistent with both activation of eosinophil and basophil (both cells involved in allergic reactions) after an acute coronary event, with the additional finding of the prognostic role of elevated eosinophil cat- ionic protein in patients with ST-segment–elevation myocardial infarc- tion. Despite these important evidences, a causality dilemma remains. In fact, it is still unclear as to whether allergic pathway activation antici- pates plaque disruption and subsequent acute thrombus formation during myocardial ischemia or, conversely, it just follows the ischemic/necrotic process. 5 The answer to this intriguing issue would permit to recognize whether allergic reactions may be considered simple bystanders or active players in the challenging pathophysiology of myocardial ischemia. Provided that further studies will support the latter hypothesis, a novel and intriguing scenario emerges, wherein avoidance of exposure to aller- genic stimuli or even specific immunotherapy may be considered as valu- able perspectives for preventing cardiac ischemic events. Disclosures None. Gianfranco Cervellin, MD Emergency Department Academic Hospital of Parma Parma, Italy Giuseppe Lippi, MD Laboratory of Clinical Chemistry and Hematology Academic Hospital of Parma Parma, Italy Nicholas G. Kounis, MD Department of Medical Sciences Southwestern Greece Highest Institute of Education and Technology Patras, Achaia, Greece References 1. Niccoli G, Calvieri C, Flego D, Scalone G, Imaeva A, Sabato V, Schiavino D, Liuzzo G, Crea F. Allergic inflammation is associated with coronary instability and a worse clinical outcome after acute myocar- dial infarction. Circ Cardiovasc Interv. 2015;8:e002554. doi: 10.1161/ CIRCINTERVENTIONS.115.002554. 2. Pfister CW, Plice SG. Acute myocardial infarction during a prolonged allergic reaction to penicillin. Am Heart J. 1950;40:945–947. 3. Kounis NG, Zavras GM. Histamine-induced coronary artery spasm: the concept of allergic angina. Br J Clin Pract. 1991;45:121–128. 4. Brawnvald E. Unstable angina. An etiologic approach to management. Circulation. 1998;98:2219–2222. 5. Lippi G, Cervellin G, Sanchis-Gomar F. Immunoglobulin E (IgE) and ischemic heart disease. Which came first, the chicken or the egg? Ann Med. 2014;46:456–463. doi: 10.3109/07853890.2014.927714. (Circ Cardiovasc Interv. 2015;8:e003166. DOI: 10.1161/CIRCINTERVENTIONS.115.003166.) © 2015 American Heart Association, Inc. Circ Cardiovasc Interv is available at http://circinterventions.ahajournals.org DOI: 10.1161/CIRCINTERVENTIONS.115.003166 Letter by Cervellin et al Regarding Article, “Allergic Inflammation Is Associated With Coronary Instability and a Worse Clinical Outcome After Acute Myocardial Infarction” Correspondence Downloaded from http://ahajournals.org by on June 9, 2020