Evaluation Of Anticoagulant Therapy By Pulmonary Perfusion/Ventilation Imaging In Patients With Chronic Thromboembolic Pulmonary Hypertension

Objective:To evaluate the effect of anticoagulant therapy by pulmonary perfusion/ventilation imaging in patients with chronic thromboembolic pulmonary hypertension(CTEPH).Methods:Thirty-six patients[16 male and 20 female,aged range(53.8± 13.8)years]diagnosed with CTEPH by pulmonary angiography were included in this study.All these patients received anticoagulant therapy for more than 6 months.They underwent pulmonary perfusion/ventilation imaging before and 6 months after anticoagulant therapy.The numbers of pulmonary segments with perfusion defect and percentage of perfusion defect scores(PPDs)calculated by quantitative analysis before and after anticoagulant therapy were compared.Pulmonary arterial systolic pressure(PASP)before and after anticoagulant therapy were measured by echocardiography.All of the results were tested for significance using student's test(P<0.05 was statistically significant).Results:The number of perfusion defect segments was(8.9 ± 3.4),and significantly reduced to(8.4±3.6)(t=3.101,P<0.01)after anticoagulant therapy.The PPDs before and after anticoagulant therapy were(43.3 ± 19.7)%and(40.8 ± 20.5)%respectively,significant difference was found between them(t=2.364,P<0.05).In the subgroup of 9 patients with improved pulmonary perfusion,the PASP significantly decreased from(68.7±27.3)mmHg to(56.1 ±34.8)mmHg(t=2.465,P<0.05)after anticoagulant therapy.In contrast,in the subgroup of 27 patients with no improved pulmonary perfusion,the PASP before and after anticoagulant therapy were(71.3 ± 26.9)mmHg and(76.7± 35.0)mmHg respectively,no difference was shown(t=-1.511,P>0.05).Conclusion:This study suggests that pulmonary perfusion/ventilation imaging is reliable method for evaluating the change of pulmonary perfusion before and after anticoagulant therapy,and it is valuable for assessing the effect of anticoagulant therapy in CTEPH patients.