Variables | Group 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±SD | 49.5±11.2 | 36.6±16.0 | 59.0±6.7 | 0.007* |
Males, n, (%) | 1 (12.5) | 4 (50.0) | 3 (43.0) | 0.31 |
Weight, kg, mean±SD | 60.9±16.0 | 69.5±14.2 | 69.7±10.2 | 0.37 |
Height, cm, mean±SD | 161.5±7.0 | 168.1±14.7 | 170.1±5.8 | 0.24 |
Simplified acute physiologic score II, point, mean±SD | 28±9 | 31±12 | – | |
Classification of pulmonary hypertension,† n (%) | – | |||
Pulmonary arterial hypertension (PAH) | ||||
Idiopathic | 3 (37.5) | 1 (12.5) | – | |
Pulmonary veno-occlusive disease‡ | 2 (25.0) | 1 (12.5) | – | |
Heritable | 1 (12.5) | 3 (37.5) | – | |
Drug-induced | 1 (12.5) | – | – | |
Pulmonary hypertension due to lung disease | ||||
Interstitial lung disease | 1 (12.5) | 3 (37.5) | – | |
Chronic lung diseases | – | – | ||
Idiopathic pulmonary fibrosis | 3 (43) | |||
Obstructive lung disease | 4 (57) | |||
Treatment of pulmonary hypertension, n (%) | ||||
Phosphodiesterase-5 inhibitors | 6 (75.0) | 5 (62.5) | – | |
Endothelin receptor antagonist | 6 (75.0) | 6 (75.0) | – | |
Parenteral prostacyclin therapy | 5 (62.5) | 5 (62.5) | – | |
Epoprostenol§ | 4 (50.0) | 2 (25.0 | ||
Treprostinil¶ | 1 (12.5) | 3 (37.5) | ||
Soluble guanylate cyclase stimulator | 0 | 1 (12.5) | – | |
Anticoagulants, n (%) | ||||
Oral anticoagulants | 1 (12.5) | 0 | – | |
Unfractionated heparin | 2 (25.0) | 4 (50) | – | |
Low-molecular-weight heparin | 5 (62.5) | 4 (50) | – | |
Identified triggering factor, n (%)** | 4 (50) | 2 (25) | ||
Biochemical variables | ||||
Creatinine at steady-state, μmol/L, mean±SD | 73±191 | 63±92 | 54±143 | 0.06 |
Creatinine during decompensated pulmonary hypertension, μmol/L, mean±SD | 111±30 | 90±30 | 54±13 | 0.002†† |
Aspartate aminotransferase, UI/mL, mean±SD | 46±27 | 218±538 | 26±8 | 0.44 |
Alanine aminotransferase, UI/mL, mean±SD | 27±11 | 347±905 | 29±8 | 0.41 |
Bilirubin, μmol/L, mean±SD | 27±16 | 19±8 | 6±2 | 0.004‡‡ |
Pro-brain natriuretic peptide, pg/mL, mean±SD | 4659±4108 | 2925±2524 | 65±36 | 0.034§§ |
Haemodynamic data | ||||
Pulmonary artery pressure, mmHg, mean±SD | 52±16 | 74±22 | 19±6 | <0.0001¶¶ |
Right atrial pressure, mmHg, mean±SD | 14.9±4.5 | 13.2±4.3 | – | 0.49*** |
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 (%) | 0 | 1 (12.5) | – | – |
Haematological variables | ||||
White blood cells, G/L, mean±SD | 6.3±2.2 | 8.4±4.1 | 10.9±6.9 | 0.58 |
Haemoglobin, g/dL, mean±SD††† | 12.2±3.2 | 13.4±1.7 | 13.1±2.5 | 0.58 |
Platelet count at steady-state, G/L, mean±SD | 180±35 | 233±38 | 255±57 | 0.013‡‡‡ |
Platelet count and characteristics during decompensated pulmonary hypertension and before ECMO placement if relevant, G/L, mean±SD§§§ | 138±8 | 207±34 | 252±47 | <0.0001¶¶¶ |
Mean platelet volume, fL, mean±SD | 10.1±1.4 | 10.0±1.2 | 10.5±0.6 | 0.78 |
Platelet distribution width, fL mean±SD | 15.4±2.7 | 11.0±2.8 | 12.1±1.5 | 0.05**** |
Mean Outcome | ||||
Post-transplant death in the ICU, n (%) | 4 (50) | 2 (25) | 0 | 0.13 |
- 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.