Increased mean platelet volume in patients with infective endocarditis and embolic events

Platelet activation appears to play an important role in thromboembolic complications of infective endocarditis (IE). Mean platelet volume (MPV) is a potentially useful marker of platelet activity and a quick and easy determinant of thrombotic risk. Hence the aim of this study was to investigate the baseline platelet volume indices (MPV and platelet distribution width [PDW]) in IE patients who developed embolic events in the follow-up period and who did not.

The study group consisted of 76 consecutive patients (female: 55, male: 21, mean age: 26 years old, ranged: 8-64 years) with definite IE according to Duke Criteria. Thirty four healthy subjects, who were age and gender adjusted, served as the control group. The mean duration of hospital stay was 44 days.

Among the IE patients, 13 (13/76, 17.1%) had major embolic events. Significantly larger vegetations were observed in patients with embolic events as compared to non-embolic group (1.4 vs. 1.0 cm, p = 0.03). MPV at hospital admission was higher in patients who had embolic events in the follow-up period compared to both those who did not and the control subjects (10.62 ± 1.13 vs. 9.25 ± 0.97 and 8.93 ± 0.82 fL, p < 0.001, respectively). Similarly, the patients with embolic events had increased PDW compared to the non-embolic ones and the control group (16.31 ± 2.42 vs. 14.35 ± 1.97 and 14.04 ± 1.82%, p < 0.001, respectively).

The present study demonstrated that IE patients with embolic events had increased MPV and PDW values, compared to non-embolics. Future prospective studies with standardized measurements may clarify the clinical role of platelet volume indices in thrombo-embolic complications of IE.