Usefulness of mean platelet volume as a marker for clinical outcomes after out‐of‐hospital cardiac arrest: comment

Abstract

I read the article by Chung and colleagues with great interest 1.Chung S.P. Yune H.Y. Park Y.S. You J.S. Hong J.H. Kong T. Park J.W. Chung H.S. Park I. Usefulness of mean platelet volume as marker for clinical outcomes after out‐of‐hospital cardiac arrest: a retrospective cohort study.J Thromb Haemost. 2016; 14: 2036-44Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar. The authors showed that elevated mean platelet volume (MPV) at admission was associated with poor neurological outcomes and mortality at 30 days. MPV levels might be a critical prognostic marker among resuscitated patients. It is an attractive result, but we have some minor criticisms about the study. MPV is a crucial parameter of platelet size and platelet activation. Recently, MPV was also proven to be a critical inflammatory marker in infectious diseases, cardiovascular diseases and immune diseases 2.Chu S.G. Becker R.C. Berger P.B. Bhatt D.L. Eikelboom J.W. Konkle B. Mohler E.R. Reilly M.P. Berger J.S. Mean platelet volume as a predictor of cardiovascular risk: a systematic review and meta‐analysis.J Thromb Haemost. 2010; 8: 148-56Crossref PubMed Scopus (723) Google Scholar, 3.Lancé M.D. Sloep M. Henskens Y.M. Marcus M.A. Mean platelet volume as a diagnostic marker for cardiovascular disease: drawbacks of preanalytical conditions and measuring techniques.Clin Appl Thromb Hemost. 2012; 18: 561-8Crossref PubMed Scopus (139) Google Scholar, 4.Leader A. Pereg D. Lishner M. Are platelet volume indices of clinical use? A multidisciplinary review.Ann Med. 2012; 44: 805-16Crossref PubMed Scopus (180) Google Scholar. However, numerous confounders could affect MPV levels 3.Lancé M.D. Sloep M. Henskens Y.M. Marcus M.A. Mean platelet volume as a diagnostic marker for cardiovascular disease: drawbacks of preanalytical conditions and measuring techniques.Clin Appl Thromb Hemost. 2012; 18: 561-8Crossref PubMed Scopus (139) Google Scholar, 4.Leader A. Pereg D. Lishner M. Are platelet volume indices of clinical use? A multidisciplinary review.Ann Med. 2012; 44: 805-16Crossref PubMed Scopus (180) Google Scholar. Some factors have been excluded or adjusted in the study, such as age, cardiovascular diseases, renal diseases, diabetes and trauma. However, several other confounders were not mentioned, including thyroid function abnormalities, hepatic failure, hypercholesterolemia and autoimmune diseases (such as ulcerative colitis, systemic sclerosis and rheumatoid arthritis, etc.). Moreover, obesity and passive smoking are proven critical determinants of MPV levels 3.Lancé M.D. Sloep M. Henskens Y.M. Marcus M.A. Mean platelet volume as a diagnostic marker for cardiovascular disease: drawbacks of preanalytical conditions and measuring techniques.Clin Appl Thromb Hemost. 2012; 18: 561-8Crossref PubMed Scopus (139) Google Scholar, 4.Leader A. Pereg D. Lishner M. Are platelet volume indices of clinical use? A multidisciplinary review.Ann Med. 2012; 44: 805-16Crossref PubMed Scopus (180) Google Scholar, 5.Yarlioglues M. Ardic I. Dogdu O. Akpek M. Zencir C. Kasapkara H.A. Kelesoglu S. Elcik D. Ozdogru I. Oguzhan A. Kaya M.G. The acute effects of passive smoking on mean platelet volume in healthy volunteers.Angiology. 2012; 63: 353-7Crossref PubMed Scopus (27) Google Scholar. Secondly, some drugs might also affect MPV levels, including statins and anticoagulant drugs 6.Mazza F. Stefanutti C. Di Giacomo S. Vivenzio A. Fraone N. Mazzarella B. Bucci A. Effects of low‐dose atorvastatin and rosuvastatin on plasma lipid profiles: a long‐term, randomized, open‐label study in patients with primary hypercholesterolemia.Am J Cardiovasc Drugs. 2008; 8: 265-70Crossref PubMed Scopus (10) Google Scholar, 7.Arik O.Z. Ozkan B. Kutlu R. Karal H. Sahin D.Y. Kaypakli O. Ozel D. Cayli M. Relationship between platelet indices and international normalized ratio in patients with non‐valvular atrial fibrillation.Platelets. 2014; 25: 311-6Crossref PubMed Scopus (9) Google Scholar. As there were 27.2% of patients with cardiovascular diseases and 15.2% of patients with previous acute coronary syndrome, the usage of statins and anticoagulant drugs might be of a high ratio. Additionally, a previous study showed a time‐dependent swelling when platelets were anticoagulated with EDTA 8.Dastjerdi M.S. Emami T. Najafian A. Amini M. Mean platelet volume measurement, EDTA or citrate ?.Hematology. 2006; 11: 317-9Crossref PubMed Scopus (129) Google Scholar. So, acid citrate‐based anticoagulation might be a better choice for blood sample collection. Generally, we think that the prognostic role of MPV in out‐of‐hospital cardiac arrest patients remains unclear. The information provided above would be helpful to estimate the clinical value of MPV in resuscitated patients. The author states that he has no conflict of interest.