CORRELATION OF MEAN PLATELET VOLUME IN PATIENTS WITH CARDIAC SYNDROME X IN INDIAN POPULATION

Platelets play a pivotal role in the development of atherosclerotic lesions, plaque destabilization and atherothrombosis. The methods of testing platelet activity can be time-consuming, expensive and technically difficult. Unlike more expensive or time-consuming methods of assessing platelet function, the determination of platelet size by quantification of Mean Platelet Volume (MPV), using automated haemograms, is simple and inexpensive. "Cardiac syndrome X" characterized with 1. Angina or angina-like chest pain, 2. ST segment depression that can be induced by treadmill exercise testing, 3. Normal coronary arteriography. As cardiac syndrome X and angina pectoris caused by typical obstructive coronary heart disease should be distinguished from each other for effective treatment. Although there has not been a clear explanation of the exact pathophysiological mechanism underlying cardiac Syndrome X, studies are suggestive that coronary micro-circular abnormalities and endothelial dysfunction play a role in the aetiology of the disease. Atherosclerosis and endothelial vasomotor dysfunction have been suggested as possible contributing factors. There are limited datas in literature to compare the MPV in cardiac syndrome X. This study was designed to compare MPVs of patients with Cardiac syndrome X, patient with CAD and of normal controls. METHODS Nine hundred and forty four patients who had undergone coronary angiography between May 2014 and April 2016 in Rajarajeshwari Medical College and Hospital, Bangalore, were retrospectively examined. Of these, 118 patients were enrolled in the study and were divided into three groups. The Cardiac Syndrome X group consisted of 40 subjects (18 men and 22 women with mean age group 45+4.2 years). The CAD group consisted of 33 subjects (18 men and 15 women with mean age of 46+4.8 years) with CAD, which was defined as >50% stenosis in a minimum of one coronary artery. The control group consisted of 45 age and sex matched individuals (23 men and 22 women with mean age of 45+4.5 years) who presented with chest pain, normal coronaries and no ischaemia during treadmill exercise testing. RESULTS The primary characteristics of the study population are given in Table 1. There was no statistical significance between the three groups with respect to age, sex, smoking or alcohol consumption (p = NS). There were no statistically significant differences in the MPV measurements between the cardiac syndrome X group and CAD groups. (Mean MPV 12.2 +/- 1.4 fL vs. 13.8 +/- 2.1 fL, p=NS). The MPV was significantly higher in both Cardiac syndrome X (mean = 12.2 +/- 1.4 fL) and CAD group (mean = 13.8 +/- 2.1 fL) compared with the control groups (mean = 7.9 +/- 1.1 fL) (p < 0.01). CONCLUSION Elevated MPVs may participate in the pathogenesis of Cardiac Syndrome X. Prospective, placebo-controlled studies with large sample sizes that use multivariable survival analyses and long-term follow-up periods are required for the clinical evaluation of the prognostic value of increased MPV in patients with Cardiac Syndrome X.