Prevalence, Genetic Background, and Clinical Phenotype of Congenital Thrombophilia in Chronic Thromboembolic Pulmonary Hypertension

Multidisciplinary Management and Staged Surgical Treatment for Chronic Thromboembolic Pulmonary Hypertension and Subclavian Vein Thrombosis Caused by Venous Thoracic Outlet Syndrome

Chronic thromboembolic pulmonary hypertension (CTEPH) is an uncommon complication of deep vein thrombosis (DVT) and pulmonary embolism (PE), occurring in 3-5% of patients despite therapeutic anticoagulation. Venous thoracic outlet syndrome (VTOS) causing subclavian vein (SCV) thrombosis is also an uncommon condition, not frequently associated with clinically significant PE. In this report, we present two patients with CTEPH and SCV thrombosis caused by VTOS who had successful multidisciplinary management and staged surgical treatment for both conditions. Each patient was young and otherwise healthy before presenting with progressively worsening shortness of breath. Both were found to have multiple peripheral PE and features of respiratory failure characteristic of CTEPH, along with axillary-SCV thrombosis and no other source of DVT. Each patient was treated with anticoagulation and riociguat but had ongoing pulmonary symptoms, and staged surgical treatment was recommended. The first stage was conducted by bilateral pulmonary thromboendarterectomy performed under deep hypothermic circulatory arrest. The second stage was conducted several months later after resolution of pulmonary hypertension, by paraclavicular thoracic outlet decompression that included complete first rib resection with a patent axillary-SCV on subsequent upper extremity imaging. Each patient recovered well with resolution of respiratory and upper extremity symptoms and a return to unrestricted activity by three months after the second operation. These patients are some of the first to have successful staged surgical treatment for CTEPH and SCV thrombosis caused by VTOS, illustrating the value of comprehensive multidisciplinary management for this unusual combination of rare conditions.

Familial onset of venous thromboembolism due to inherited antithrombin deficiency with a novel gene variant (p.Arg14Gly)

Inherited antithrombin deficiency is an autosomal dominant thrombophilia, resulting from genetic variations in the serpin family C member 1 (SERPINC1) gene. Antithrombin deficiency increases the risk of venous thromboembolism (VTE) compared to the general population. In this report, a novel missense variant of SERPINC1, c.40A>G, p.Arg14Gly that predicts to cause secretion defect of antithrombin, was identified in two related patients: a 65-year-old man with chronic thromboembolic pulmonary hypertension (CTEPH) after acute pulmonary embolism, and his son with early onset of VTE. Treatment with direct oral anticoagulants and catheter interventions led to successful outcomes for both patients. These cases highlight the importance of screening testing for inherited antithrombin deficiency and intrafamilial survey in patients with VTE and CTEPH.

Learning objectives

Inherited antithrombin deficiency is associated with a strong risk of venous thromboembolism (VTE). However, the relationship between inherited antithrombin deficiency and chronic thromboembolic pulmonary hypertension (CTEPH) remains unclear. The influence of antithrombin deficiency on developing CTEPH following acute pulmonary embolism requires further investigation. This report emphasizes the importance of screening for thrombophilic factors in cases of VTE and CTEPH.

Congenital thrombophilia in East-Asian venous thromboembolism population: a systematic review and meta-analysis

Background

Various inherited traits contribute to the overall risk of venous thromboembolism (VTE). In addition, the epidemiology of thrombophilia in the East-Asian VTE population remains unclear; thus, we aimed to assess the proportion of hereditary thrombophilia via a meta-analysis.

Methods

Publications from PubMed, EMBASE, web of science, and Cochrane before December 30, 2022, were searched. Studies from Japan, Korea, China, Hong Kong, Taiwan, Singapore, Thailand, Vietnam, Myanmar, and Cambodia were included. Congenital thrombophilia was described as diseases including protein C (PC) deficiency, protein S (PS) deficiency, antithrombin (AT) deficiency, factor (F)V Leiden (FVL), and prothrombin G20210A mutations. Studies were selected by 2 reviewers for methodological quality analysis. A random-effects model was used for the meta-analysis, assuming that estimated effects in the different studies are not identical.

Results

Forty-four studies involving 6453 patients from 7 counties/regions were included in the meta-analysis. The prevalence of PC, PS, and AT deficiencies were 7.1%, 8.3%, and 3.8%, respectively. Among 2924 patients from 22 studies, 5 patients were carriers of FVL mutation. Among 2196 patients from 10 studies, 2 patients were carriers of prothrombin G20210A mutation in a Thailand study.

Conclusion

The prevalence of PC, PS, and AT deficiencies was relatively high, while a much lower prevalence of FVL and prothrombin G20210A mutations were identified in East-Asian patients with VTE. Our data stress the relative higher prevalence of PC, PS, and AT deficiencies for thrombophilia in the East-Asian VTE population.

Combination Treatment of Balloon Pulmonary Angioplasty and Direct Oral Anticoagulant in a Patient with Chronic Thromboembolic Pulmonary Hypertension Complicated by Protein S Deficiency

Introduction: Chronic thromboembolic pulmonary hypertension (CTEPH) is a phenotype of pulmonary hypertension due to chronic and multiple organized thrombus. The therapeutic strategy for patients with CTEPH and comorbid protein S deficiency remains unknown due to its rarity. Case: We encountered a 49-year-old male patient with CTEPH and concomitant mild protein S deficiency (type III). We could successfully perform balloon pulmonary angioplasty without any major complications, including thromboembolism and bleeding, followed by standard-dose oral anticoagulation therapy instead of warfarin. Conclusion: A currently established standard therapeutic strategy for CTEPH, including pulmonary angioplasty, may be safe and effective even in patients with concomitant inherent coagulation abnormalities.