title: Incidence and risk factors of chronic thromboembolic pulmonary hypertension in patients after acute pulmonary embolism.
abstract: BACKGROUND
  Early identification and treatment of chronic thromboembolic pulmonary hypertension (CTEPH) are critical to prevent disease progression. We determined the incidence and risk factors for CTEPH in patients with a first episode of acute pulmonary embolism (PE).
  
  
  METHODS
  In this study, consecutive patients with first-episode acute PE were followed for ≤5 years. Pulmonary hypertension (PH) was screened for by echocardiography. Suspected cases were evaluated by right heart catheterization (RHC) and pulmonary angiography (PA). If invasive procedures were not permitted, PH was diagnosed by systolic pulmonary artery pressure (SPAP) >50 mmHg. Diagnosis of CTEPH was confirmed by PA, ventilation/perfusion (V/Q) lung scan, or computed tomography (CT) PA (CTPA).
  
  
  RESULTS
  Overall, 614 patients with acute PE were included (median follow-up, 3.3 years). Ten patients were diagnosed with CTEPH: cumulative incidence 0.8% [95% confidence interval (CI), 0.0-1.6%] at 1 year, 1.3% (95% CI, 0.3-2.3%) at 2 years, and 1.7% (95% CI, 0.7-2.7%) at 3 years. No cases of CTEPH developed after 3 years. History of lower-limb varicose veins [hazard ratio (HR), 4.3; 95% CI, 1.2-15.4; P=0.024], SPAP >50 mmHg at initial PE episode (HR, 23.5; 95% CI, 2.7-207.6; P=0.005), intermediate-risk PE (HR, 1.2; 95% CI, 1.0-1.4; P=0.030), and CT obstruction index over 30% at 3 months after acute PE (HR, 42.5; 95% CI, 4.4-409.8; P=0.001) were associated with increased risk of CTEPH.
  
  
  CONCLUSIONS
  CTEPH was not rare after acute PE in this Chinese population, especially within 3 years of diagnosis. Lower-limb varicose veins, intermediate-risk PE with elevated SPAP in the acute phase, and residual emboli during follow-up might increase the risk of CTEPH.
authors.affiliation: 1 Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China ; 2 Beijing Institute of Respiratory Medicine, Beijing 100020, China ; 3 Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing 100020, China ; 4 Center of Respiratory Medicine, Beijing Hospital, Ministry of Health, Beijing 100730, China ; 5 Department of Cardiothoracic Surgery, Baylor College of Medicine, Houston, Texas, USA ; 6 Department of Respiratory Medicine, Capital Medical University, Beijing 100069, China ; 7 China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Suqiao
authors.initials: S
authors.lastname: Yang
authors.affiliation: 1 Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China ; 2 Beijing Institute of Respiratory Medicine, Beijing 100020, China ; 3 Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing 100020, China ; 4 Center of Respiratory Medicine, Beijing Hospital, Ministry of Health, Beijing 100730, China ; 5 Department of Cardiothoracic Surgery, Baylor College of Medicine, Houston, Texas, USA ; 6 Department of Respiratory Medicine, Capital Medical University, Beijing 100069, China ; 7 China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Yuanhua
authors.initials: Y
authors.lastname: Yang
authors.affiliation: 1 Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China ; 2 Beijing Institute of Respiratory Medicine, Beijing 100020, China ; 3 Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing 100020, China ; 4 Center of Respiratory Medicine, Beijing Hospital, Ministry of Health, Beijing 100730, China ; 5 Department of Cardiothoracic Surgery, Baylor College of Medicine, Houston, Texas, USA ; 6 Department of Respiratory Medicine, Capital Medical University, Beijing 100069, China ; 7 China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Zhenguo
authors.initials: Z
authors.lastname: Zhai
authors.affiliation: 1 Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China ; 2 Beijing Institute of Respiratory Medicine, Beijing 100020, China ; 3 Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing 100020, China ; 4 Center of Respiratory Medicine, Beijing Hospital, Ministry of Health, Beijing 100730, China ; 5 Department of Cardiothoracic Surgery, Baylor College of Medicine, Houston, Texas, USA ; 6 Department of Respiratory Medicine, Capital Medical University, Beijing 100069, China ; 7 China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Tuguang
authors.initials: T
authors.lastname: Kuang
authors.affiliation: 1 Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China ; 2 Beijing Institute of Respiratory Medicine, Beijing 100020, China ; 3 Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing 100020, China ; 4 Center of Respiratory Medicine, Beijing Hospital, Ministry of Health, Beijing 100730, China ; 5 Department of Cardiothoracic Surgery, Baylor College of Medicine, Houston, Texas, USA ; 6 Department of Respiratory Medicine, Capital Medical University, Beijing 100069, China ; 7 China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Juanni
authors.initials: J
authors.lastname: Gong
authors.affiliation: 1 Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China ; 2 Beijing Institute of Respiratory Medicine, Beijing 100020, China ; 3 Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing 100020, China ; 4 Center of Respiratory Medicine, Beijing Hospital, Ministry of Health, Beijing 100730, China ; 5 Department of Cardiothoracic Surgery, Baylor College of Medicine, Houston, Texas, USA ; 6 Department of Respiratory Medicine, Capital Medical University, Beijing 100069, China ; 7 China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhang
authors.affiliation: 1 Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China ; 2 Beijing Institute of Respiratory Medicine, Beijing 100020, China ; 3 Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing 100020, China ; 4 Center of Respiratory Medicine, Beijing Hospital, Ministry of Health, Beijing 100730, China ; 5 Department of Cardiothoracic Surgery, Baylor College of Medicine, Houston, Texas, USA ; 6 Department of Respiratory Medicine, Capital Medical University, Beijing 100069, China ; 7 China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Zhu
authors.affiliation: 1 Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China ; 2 Beijing Institute of Respiratory Medicine, Beijing 100020, China ; 3 Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing 100020, China ; 4 Center of Respiratory Medicine, Beijing Hospital, Ministry of Health, Beijing 100730, China ; 5 Department of Cardiothoracic Surgery, Baylor College of Medicine, Houston, Texas, USA ; 6 Department of Respiratory Medicine, Capital Medical University, Beijing 100069, China ; 7 China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Lirong
authors.initials: L
authors.lastname: Liang
authors.affiliation: 1 Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China ; 2 Beijing Institute of Respiratory Medicine, Beijing 100020, China ; 3 Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing 100020, China ; 4 Center of Respiratory Medicine, Beijing Hospital, Ministry of Health, Beijing 100730, China ; 5 Department of Cardiothoracic Surgery, Baylor College of Medicine, Houston, Texas, USA ; 6 Department of Respiratory Medicine, Capital Medical University, Beijing 100069, China ; 7 China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Ying H
authors.initials: YH
authors.lastname: Shen
authors.affiliation: 1 Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China ; 2 Beijing Institute of Respiratory Medicine, Beijing 100020, China ; 3 Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing 100020, China ; 4 Center of Respiratory Medicine, Beijing Hospital, Ministry of Health, Beijing 100730, China ; 5 Department of Cardiothoracic Surgery, Baylor College of Medicine, Houston, Texas, USA ; 6 Department of Respiratory Medicine, Capital Medical University, Beijing 100069, China ; 7 China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
keywords: China; Incidence; chronic thromboembolic pulmonary hypertension (CTEPH); pulmonary embolism (PE); risk factors