Comparison of mean platelet volume values among different causes of pulmonary hypertension.

BACKGROUND Pulmonary hypertension is caused by a heterogenous group of disorders with diverse pathophysiological mechanisms, with ultimate structural changes in the pulmonary vascular bed. Platelet activation plays an important role in the development of pulmonary arterial hypertension, while it is unknown whether it contributes to pathogenesis in other conditions. We aimed to investigate platelet activation in different causes of pulmonary hypertension by means of mean platelet volume measurement. METHODS A total of 67 patients with different causes of pulmonary hypertension, and 31 controls, were retrospectively reviewed. Patients with pulmonary hypertension were further grouped according to underlying disease, including pulmonary arterial hypertension, pulmonary hypertension due to left ventricular failure, and pulmonary hypertension due to chronic obstructive pulmonary disorder. All patients and controls past medical data, admission echocardiograms and complete blood counts were reviewed. RESULTS Patients with pulmonary hypertension had higher mean platelet volume levels compared to healthy controls (8.77 ± 1.18 vs 7.89 ± 0.53; p < 0.001), and statistical significance was still present when pulmonary arterial hypertension patients were not included in the pulmonary hypertension group (8.59 ± 1.23 vs 7.89 ± 0.53; p < 0.001). Among patients with pulmonary hypertension, the pulmonary arterial hypertension group and the pulmonary hypertension due to left ventricular failure group had higher mean platelet volumes compared to healthy controls. Mean platelet volume did not correlate with pulmonary artery pressure. CONCLUSIONS Our results indicate that mean platelet volume is not only elevated in pulmonary arterial hypertension, but also due to other causes of pulmonary hypertension.