Epidemiological Study of Chronic Thromboembolic Pulmonary Hypertension in China

Chronic thromboembolic pulmonary hypertension (CTPH) is associated with considerable morbidity and mortality. Its incidence after pulmonary embolism and associated risk factors are not well documented in Chinese population. We conducted a prospective, long-term, follow-up study to assess the incidence of symptomatic CTPH in consecutive patients with an acute episode of pulmonary embolism but without prior venous thromboembolism. Patients with unexplained persistent dyspnea during follow-up underwent transthoracic echocardiography and, if supportive findings were present, ventilation-perfusion lung scanning and pulmonary angiography. CTPH was considered to be present if systolic and mean pulmonary-artery pressures exceeded 40 mm Hg and 25 mm Hg, respectively; pulmonary-capillary wedge pressure was normal; and there was angiographic evidence of disease.

Inclusion Criteria:

• Patients with an episode of acute symptomatic pulmonary embolism without prior pulmonary embolism or venous thrombosis

Exclusion Criteria:

• Have other diseases (e.g., systemic sclerosis or severe emphysema) that could have caused nonthromboembolic pulmonary hypertension,
• Have preexisting exertional dyspnea,
• Geographically inaccessible for follow-up,
• Decline to participate in the study.