ABC | Volume 112, Nº6, June 2019

Original Article Clinical Significance of Platelet Volume and Other Platelet Parameters in Acute Myocardial Infarction and Stable Coronary Artery Disease Liumei Ding, 1 Lihua Sun, 2 F eng Wang, 1 Liejun Zhu, 1 Ting Zhang, 1 F anli Hua 2 Clinical Laboratory - Jinshan Hospital of Fudan University, 1 Shanghai – China Department of Hematology - Zhongshan Hospital, 2 Qingpu Branch, Shanghai – China Liumei Ding and Lihua Sun contributed equally to this work as the first authorship. Mailing Address: Fanli Hua • N°. 1158 of East Gongyuan Road, Qingpu District. 201700, Shanghai - China E-mail: huafanli_cn@163.com Manuscript received May 21, 2018, revised manuscript September 28, 2018, accepted November 14, 2018 DOI: 10.5935/abc.20190058 Abstract Background: Platelets are important in the initiation of thrombosis, and their morphological and functional changes are closely related with the occurrence and development of coronary artery thrombosis. Platelet parameters might be valuable in distinguishing between acute myocardial infarction (AMI) and stable coronary artery disease (SCAD). Objective: This study was designed to detect and compare changes in platelet parameters, such as mean platelet volume (MPV) in patients with acute myocardial infarction (AMI) and stable coronary artery disease (SCAD) and to investigate their roles in these diseases. Methods: Specimen collection: Between January 2011 and December 2013, 2 mL of elbow vein blood was drawn from each of 31 patients primarily diagnosed with AMI, 34 SCAD patients and 50 healthy subjects; and placed in EDTA-K2 anticoagulant tubes. Platelet count (PLT), MPV, plateletcrit (PCT), platelet distribution width (PDW), white blood cell (WBC) and neutrophil (NEU) counts were determined using an STKS automated hematology analyzer (Beckman Courter). Results: Compared with the control group, MPV levels were significantly higher in the AMI and SCAD groups (p < 0.05), while PLT was significantly lower (p < 0.05). Conclusion: These results suggest that MPV and other related parameters have a certain value in the diagnosis of SCAD and AMI. (Arq Bras Cardiol. 2019; 112(6):715-719) Keywords: Acute Coronary Syndrome/physiopathology; Coronary Thrombosis; Mean Platelet Volume; Myocardial Infarction. Introduction Acute coronary syndromes (ACS) are a group of clinical syndromes, of which pathological bases are coronary atherosclerosis plaques rupture or erosion, 1 followed by complete or incomplete occlusive thrombosis. ACS include acute myocardial infarction (AMI) and unstable angina pectoris. Among these, AMI refers to acute focal myocardial necrosis caused by prolonged and severe myocardial ischemia. 2 In 2013, the European Society of Cardiology issued the management guidelines for stable coronary artery disease (SCAD). 3 These guidelines clearly pointed out that SCAD also include situations of no symptoms or stable symptoms after the stabilization of acute coronary syndrome, besides stable angina pectoris. These situations cannot be clearly distinguished from ACS. Previous studies have revealed that platelet is an important medium in the initiation of thrombosis, and its morphological and functional changes are closely correlated with the occurrence and development of coronary artery thrombosis. 4,5 Additionally, mean platelet volume (MPV), one of the platelet parameters in AMI, is significantly higher than in normal subjects, hence MPV is considered as a predictor for AMI. 6 However, the value of platelet parameters in distinguishing between AMI and SCAD has not been reported in China. It has been reported that the supersensitive troponin level was elevated in patients with SCAD. 7 Although it did not reach the threshold for the diagnosis of myocardial infarction, the prognosis was poorer, when compared with SCAD patients without an elevated troponin level. In our study, differences in platelet parameters such as MPV in AMI patients, SCAD patients and healthy subjects were analyzed, and the significance of these parameters for predicting the disease was investigated. Methods General Information A total of 31 patients primarily diagnosed with AMI were enrolled in this study. All patients had been diagnosed for the first time, did not undergo anticoagulation or stent percutaneous coronary intervention, and met the international and Chinese guidelines for the diagnosis of AMI. Of these patients, 23 patients were males and eight patients were females; and the mean age of these patients was 64.4 ± 11.6 years. Thirty‑four patients were diagnosed with SCAD. These patients were required to meet the following criteria: (1) patients diagnosed with AMI for more than two months; (2) patients without pectoralgia; (3) patients who were receiving anticoagulation drug treatment. Of these patients, 28 patients were males and six patients were females; the mean age of these patients was 60.6 ± 13.1 years. The control group comprised 50 healthy subjects who underwent physical examinations at theOutpatient Department. 715