Objective: The accurate underlying pathogenic mechanism behind spontaneous echo contrast (SEC) is complex and poorly understood. The aim of this study was to characterize the relationship between platelet indices and left atrium SEC in patients with mitral stenosis (M.S).

Material and Methods: A total of 102 consecutive patients with M.S were enrolled to the study. Transthoracic echocardiography (TTE) and transoesophageal echocardiography (TEE) were performed for each patient to rule out the thrombus formation in the left atrium (LA). The study population were divided into two groups according to the formation of SEC in the LA: Group 1 (SEC–): M.S without SEC; Group II (SEC +): M.S complicated with SEC. Group I included 60 patients, and group II included 42 patients.

Results: Mean platelet volume ( MPV) levels (10.15 ± 0.60 vs. 9.6 ± 1.4, p <0.001) and   plateletcrit levels (0.238 ± 0.02 vs. 0.222 ± 0.05, p = 0.007) were significantly higher in the SEC (+) group. There was significant increase in MPV values with increase in severity of SEC (p<0.001).

Conclusion:  In patients with M.S, platelet indices including MPV and PCT levels were associated with the presence of SEC and were independent risk factors of SEC. MPV levels correlated with severity of SEC.