Mean platelet volume levels predict pulmonary artery hypertension in patients with atrial septal defect.

Introduction: Some reports have shown increased platelet aggregation and activation in patients with pulmonary artery hypertension (PAH). Mean platelet volume (MPV) is a simple and easy method of assessing platelet function. We aimed to investigate the mean platelet volume levels in patients with atrial septal defect (ASD) and the association between MPV levels and pulmonary artery hypertension.

Method: One hundred and forty consecutive patients (42 males and mean age 35 +/- 9 y) and forty healthy controls (15 males and mean age 35 +/- 4 y) were enrolled in the study between December 2008 and February 2011.

Results: The ASD group demonstrated a significantly higher right ventricular size and pulmonary artery pressure than the control group (42 +/- 4 mm vs. 36 +/- 3 mm and 43 +/- 12 mmHg vs. 32 +/- 11 mmHg; P < 0.001 and P < 0.001, respectively). MPV levels were higher in the ASD group than the control group (9.3 +/- 1.2 fl vs. 8.6 +/- 0.8 fl, P < 0.001). There was a significant, positive correlation between MPV and systolic pulmonary artery pressure (PAP) (r = 0.542 and P < 0.001) in the ASD group. MPV was also significantly correlated with right ventricular size but not ASD diameter in the ASD group (r = 0.441, P < 0.001 and r = 0.126, P = 0.268, respectively). In receiver operating characteristics curve analysis, the cut-off value of MPV levels was > 8.7 fl and had 82% sensitivity and 63% specificity in predicting pulmonary artery hypertension.

Conclusion: In the present study, we found that MPV levels, an indicator of platelet activation, were significantly higher in patients with ASD and correlated with systolic pulmonary artery pressure and right ventricular diameter.