LONG-TERM HEMATOLOGICAL MANAGEMENT OF CYA NOTIC CONGENITAL HEART-DISEASE

The long-term management of cyanotic congenital heart disease requires treatment of raised haematocrit (> 65 %) whilst conserving the qualit y of the red blood cells [mean corpuscular volume, mean corpuscular ha emoglobin concentration (MCHC)]. Since 1975, the author has chosen che motherapy (hydroxyurea, pipobroman) as first-line treatment, reserving iron supplements, phlebotomy and platelet antagonists as adjuvant the rapy. Pre-treatment data of 170 patients showed: a high prevalence of hypochromic microcytosis due to iron deficiency and of thrombopaenia, in relation to the severity and duration of the polycythaemia. Hyperur icaemia was greater than 420 mu mol/l in 67 % of cases; effort toleran ce and hyperviscosity were related to the haematocrit and iron deficie ncy. One hundred and forty seven patients were followed up for a total duration of 769 years of chemotherapy: Clinical tolerance was good: b iological tolerance was marked by a high frequency of thrombocytopaeni a requiring withdrawal (10 cases) or reduction of treatment (34 cases) . The causes of the 39 deaths observed are analysed : none was related to the hydroxyurea or pipobroman. The treatment or follow-up was stop ped in 29 cases : the reasons are reported. Seventy eight patients und er treatment had a favourable outcome with normal social reinsertion i n 74 cases. This efficiency was related to maintenance of a haematocri t < 65 %, to correction of the iron deficiency and increase in the MCH C. These results were obtained with an average dosage of 19 +/- 14.5 m g/kg/day of hydroxyurea (69 patients). By slowing erythropoiesis, chem otherapy reduces the indication of phlebotomy, so reducing iron loss : it also inhibits excessive bouts of polycythaemia in cases of iron th erapy. Early treatment before the haematocrit reaches 65 %, reduces th e frequency of thrombocytopaenia. The role of platelets in the pathoge nesis of cerebral and pulmonary infarction is discussed and their resp onsibility in the evolution of Eisenmenger' s syndrome; theoretically, it justifies the use of platelet antiaggregants from childhood.