Thrombocytopenia in pulmonary hypertension, does it predict survival?

Abstract

Purpose: Pulmonary hypertension due to congenital heart disease causes severe cyanosis due to Eisenmenger syndrome. We often have our patients investigated for thrombocytopenia and so we wished to find if there was an obvious underlying association to explain this. Methods: Many patients from our pulmonary hypertension clinic had undergone blood sampling which we were able to review retrospectively from our results database. We reviewed the demographic data, haematology results, cause and severity of the pulmonary hypertension and the oxygen saturations from the clinics. Results: We found 93 patients with complete blood results in our database over the last 2 years and reviewed their data. 39 of these patients (%) had a low platelet count ( 0.05). The rest had more minor congenital heart disease or Fontan operation (22), chronic lung disease (12), sickle cell disease (3), connective tissue disease (5), left heart disease (11) or chronic thrombo-embolic pulmonary hypertension (3). There was no correlation between the platelet count and the degree of pulmonary hypertension, mean (sd) systolic pulmonary pressure in group L was 63 (21) mmHg and mean N group was 61 (17) mmHg. The prognosis was worst for those with severe thrombocytopenia, with 7/39 dying in group L during the period of observation as compared to only 2/54 in group N. There was no correlation with iron deficiency (as judged by the MCV, mean L = 93, mean H = 90). Conclusions: We have found that there is significant thrombocytopenia in our patient population which is associated with poor survival. At the current time we are not clear whether this is dilutional due to the erythrocythosis or due to bone marrow hypoxaemia. Further studies are required to determine the cause of this but it does not seem that these patients require routine haematology investigations for thrombocytopenia in the presence of severe pulmonary hypertension.