Platelet Activation Markers in Children with Congenital Heart Disease Associated with Pulmonary Arterial Hypertension

Background: Mean platelet volume (MPV), platecrit, and platelet distribution width (PDW) are markers of platelet activation. Previous studies have found that platelet activation occurs in patients with pulmonary arterial hypertension. Platelet indices including MPV, PDW, and platecrit have not been studied in children with congenital heart disease associated pulmonary arterial hypertension (APAH-CHD) who survived and those who died. Objective: The objective of this study to investigate the value of platelet indices with clinical and hemodynamic indicators predicting the disease severity and survival in children with APAH-CHD. Methods: This was a nested case-control study. MPV, platecrit, and PDW levels measured in 37 patients with APAH-CHD and 43 healthy subjects at the beginning of the study. Right heart catheterization was performed in all 37 patients. Clinical and hemodynamic data were collected. All patients were followed from the date of laboratory testing. The study was conducted between March 2012-July 2015. The comparison of clinical, hemodynamic data and platelet indices were made between patients with APAH-CHD who died than APAH-CHD patients who survived. Results: Of 37 patients, after a mean follow-up duration of 67.90647.90 months, 11 patients died. MPV (12.10 femoliter [fL; 8.20-12.50] vs 8.70 fL [6.40-9.70], P5.007), PDW (16.88 +/- 1.09% vs 15.75 +/- 1.58%, P = .04) and platecrit (0.28 +/- 0.31 vs 0.22 +/- 0.27, P = .01) were significantly higher in the patients with APAH-CHD who died than those who survived. Pearson's correlation analysis showed that MPV correlated with mean pulmonary artery pressure (r = 0.332, P = .04) and correlated negatively with six-minute walking distance (r = -0.600. P = .00). PDW and platecrit correlated positively with mean pulmonary artery pressure (r = 0.373, P = .02; r = 0.389, P = .01, respectively). Conclusion: Our results showed that MPV, platecrit and PDW were increased in children with APAH-CHD. They might give clue about disease severity.