Pulmonary hypertension in patients with hematological disorders following splenectomy

Abstract

Prevalence of pulmonary arterial hypertension (PAH) was studied by Echocardiography and Doppler in 43 splenectomised patients with various disorders 1-20 years after splenectomy. PAH was detected only in thalassemia major, intermedia, hereditary sphereocytosis and myelofibrosis groups comprising a total of 21 patients. Six patients out of 21 was found to have PAH with mean pulmonary arterial pressure of 46.28 ± 28.17 mmHg. Twenty one controls having similar duration and type of disease also were assessed for PAH in this case control study 3/21 had PAH in this control group. The difference in number of patients showing pulmonary hypertension between case and control was not statistically significant (chi-square test p = 0.29-though the difference in pulmonary arterial pressure between case and control were significantly different (t-test p<0.0029) with control group showing a mean pulmonary arterial pressure of 25 ± 19 mmHg.Platelet count in the splenectomised group was significantly higher (p = 0.0029) than the controls. Pulmonary thromboembolism was equally high in the PAH patients with and without splenectomy. Patients undergoing splenectomy due to trauma, immune thrombocytopenia, sideroblastic anemia, extra hepatic portal hypertension, autoimmune hemolytic anemia did not show PAH after splenectomy even years after the procedure PAH following splenectomy is common after certain disorders and control patients with these diseases have tendency to develop PAH even without splenectomy. Pulmonary thromboembolism may be an important pathophysiological mechanism leading to this condition. Patients having hemolytic anemia and myelofibrosis should have regular evaluation of pulmonary arterial pressure whether he/she has been splenectomised or not. This is particularly important as availability of phosphodiesterase inhibitors like sildenafil allows one to manage these cases.

Prevalence and Risk Factors for Pulmonary Arterial Hypertension in a Large Group of β-Thalassemia Patients Using Right Heart Catheterization

“…42 The association of thrombocytosis, increased platelet activation, increased levels of nucleated red blood cells, and other markers of hypercoagulability with PAH in patients with β-thalassemia (mostly intermedia) have been reported, even in patients with no evidence or history of pulmonary embolic disease. 19,24,25,34,39,43 Other factors are also suggested to cause PAH in β-thalassemia. Associations between lower hemoglobin levels and increased markers of hemolysis with this morbidity have been reported.…”

Patients After Splenectomy: Old Risks and New Perspectives

“…Meera et al found out that patients suffering from thalassemia, myelofibrosis or hereditary spherocytosis who underwent splenectomy are at risk for developing PH (27). One of the mechanisms that could explain PH in splenectomized patients is that the abnormal red blood cells have a higher life span and they might activate the platelets which become entrapped in the pulmonary circulation, leading to an increased pressure (28).…”

“…The conditions associated with PH after splenectomy are responsible for PH even in non-splenectomized patients, but the mean pulmonary artery pressure is higher in splenectomized individuals. Therefore, caution is needed when recommending splenectomy to patients suffering from PH (27).…”

Pulmonary Hypertension Associated with Chronic Hemolytic Anemia and Other Blood Disorders

“…47,141 A recent study of 43 patients with various disorders and reasons for splenectomy found a higher occurrence of PH in these patients than in case controls; however, the diagnosis was made by echocardiography and not confirmed by RHC. 142 …”

“…Asplenia has also been reported as an independent risk factor for PH following splenectomy for HS, 98–100 idiopathic thrombocytopenic purpura, 47 and other hemolytic disorders. 104,105,142 There is also evidence that splenectomy can increase the risk of PH in patients who do not have hemolytic disorders, such as trauma 47 and Gaucher disease. 144 These observations suggest that asplenia may be a risk factor for PH regardless of the underlying condition.…”