Table 1

Patient characteristics and biological variables

VariablesGroup 1 (platelet count<150 G/L) (n=8)Group 2 (platelet count≥150 G/L) (n=8)Controls (n=7)ANOVA or Fisher’s exact test
General characteristics
Age, y, mean±SD49.5±11.236.6±16.059.0±6.70.007*
Males, n, (%)1 (12.5)4 (50.0)3 (43.0)0.31
Weight, kg, mean±SD60.9±16.069.5±14.269.7±10.20.37
Height, cm, mean±SD161.5±7.0168.1±14.7170.1±5.80.24
Simplified acute physiologic score II, point, mean±SD28±931±12
Classification of pulmonary hypertension,† n (%)
 Pulmonary arterial hypertension (PAH)
  Idiopathic3 (37.5)1 (12.5)
  Pulmonary veno-occlusive disease‡2 (25.0)1 (12.5)
  Heritable1 (12.5)3 (37.5)
  Drug-induced1 (12.5)
 Pulmonary hypertension due to lung disease
  Interstitial lung disease1 (12.5)3 (37.5)
 Chronic lung diseases
  Idiopathic pulmonary fibrosis3 (43)
  Obstructive lung disease4 (57)
Treatment of pulmonary hypertension, n (%)
 Phosphodiesterase-5 inhibitors6 (75.0)5 (62.5)
 Endothelin receptor antagonist6 (75.0)6 (75.0)
 Parenteral prostacyclin therapy5 (62.5)5 (62.5)
  Epoprostenol§4 (50.0)2 (25.0
  Treprostinil¶1 (12.5)3 (37.5)
 Soluble guanylate cyclase stimulator01 (12.5)
 Anticoagulants, n (%)
  Oral anticoagulants1 (12.5)0
  Unfractionated heparin2 (25.0)4 (50)
  Low-molecular-weight heparin5 (62.5)4 (50)
Identified triggering factor, n (%)**4 (50)2 (25)
Biochemical variables
Creatinine at steady-state, μmol/L, mean±SD73±19163±9254±1430.06
Creatinine during decompensated pulmonary hypertension, μmol/L, mean±SD111±3090±3054±130.002††
Aspartate aminotransferase, UI/mL, mean±SD46±27218±53826±80.44
Alanine aminotransferase, UI/mL, mean±SD27±11347±90529±80.41
Bilirubin, μmol/L, mean±SD27±1619±86±20.004‡‡
Pro-brain natriuretic peptide, pg/mL, mean±SD4659±41082925±252465±360.034§§
Haemodynamic data
Pulmonary artery pressure, mmHg, mean±SD52±1674±2219±6<0.0001¶¶
Right atrial pressure, mmHg, mean±SD14.9±4.513.2±4.30.49***
Dobutamine, n (%)8 (100)5 (62.5)
Norepinephrine, n (%)6 (75)3 (37.5)
Pretransplantation veno-arterial ECMO, n (%)3 (37.5)1 (12.5)
Pretransplantation veno-venous ECMO, n (%)01 (12.5)
Haematological variables
White blood cells, G/L, mean±SD6.3±2.28.4±4.110.9±6.90.58
Haemoglobin, g/dL, mean±SD†††12.2±3.213.4±1.713.1±2.50.58
Platelet count at steady-state, G/L, mean±SD180±35233±38255±570.013‡‡‡
Platelet count and characteristics during decompensated pulmonary hypertension and before ECMO placement if relevant, G/L, mean±SD§§§138±8207±34252±47<0.0001¶¶¶
 Mean platelet volume, fL, mean±SD10.1±1.410.0±1.210.5±0.60.78
 Platelet distribution width, fL mean±SD15.4±2.711.0±2.812.1±1.50.05****
Mean Outcome
Post-transplant death in the ICU, n (%)4 (50)2 (25)00.13
  • - Creatinine at steady state vs creatinine during decompensated pulmonary hypertension (paired-samples t-test procedure): 1P=0.003, 2P=0.001, 3P=0.93.

  • - For the ANOVA or X2 test, P values ≤0.05 were considered statistically significant. Group 1: pulmonary hypertension and thrombocytopenia. Group 2: Pulmonary hypertension and normal platelet count.

  • *Group 2 vs. controls, P=0.007

  • †Pulmonary arterial hypertension plexiform lesions were found in native lungs from five patients with severe thrombocytopenia, three patients with moderate thrombocytopenia, and none of the controls (P=0.04).

  • ‡A specific association with platelet aggregates was not observed.

  • §Epoprostenol was prescribed in five patients in group 1 (mean dose=37.7±12.4 ng/kg/min) and two patients in group 2 (mean dose=22.5±2.1 ng/kg/min).

  • ¶Treprostinil was prescribed in one patient in group 1 (dose=31 ng/kg/min) and three patients in group 2 (mean dose=34.0±12.8 ng/kg/min).

  • **Triggering factor: group 1= infection (n=2), haemorrhage (n=1), effort (n=1); group 2=thrombosis of Potts shunt (n=1), haemorrhage (n=1). In other cases, acute PH decompensation was a manifestation of disease worsening.6

  • ††Group 1 vs. controls, P=0.002; Group 2 vs. controls, P=0.04.

  • ‡‡Group 1 vs. controls, P=0.004.

  • §§Group 1 vs. controls, P=0.036.

  • ¶¶Group 1 vs. controls, P=0.016; Group 2 vs. controls, P<0.0001.

  • ***By Student's t-test.

  • †††There was no evidence of a microangiopathic picture on blood smears (absence of schizocytes) and haemolysis index was zero.

  • ‡‡‡Group 1 vs. controls, P=0.016.

  • §§§A median of 25.5 day [IQR 10.0-72.0] elapsed between the steady-state platelet count and that taken on the day of pulmonary hypertension decompensation.

  • ¶¶¶Group 1 vs. group 2, P=0.002; Group 1 vs. controls, P<0.0001; Group 2 vs. controls, P=0.005.

  • ****Group 1 vs. group 2, P=0.06.

  • ECMO, extracorporeal membrane oxygenation; ICU, intensive care unit.