Prevalence of undiagnosed chronic thromboembolic pulmonary hypertension after pulmonary embolism.

Chronic thromboembolic pulmonary hypertension is associated with adverse prognosis. Early diagnosis is important to better identify patients who would benefit from a well established therapeutic strategy. The purpose of our study was to evaluate long-term incidence of undiagnosed chronic thromboembolic pulmonary hypertension after acute pulmonary embolism and the utility of a long-term follow-up including an echocardiographic-based screening programme to early detect this disease. We evaluated retrospectively 282 patients discharged from the 'Maggiore della Carità' Hospital, Università del Piemonte Orientale, Novara, Italy, with diagnosis of acute pulmonary embolism between November 2006 and October 2009. One hundred and eleven patients underwent a clinical late echocardiographic screening programme after the acute event. Patients with suspected pulmonary hypertension based on echocardiographic evidence of systolic pulmonary artery pressure of at least 40  mmHg underwent complete work-up for chronic thromboembolic pulmonary hypertension assessment, including ventilation-perfusion lung scintigraphy and right heart catheterization. One hundred and eleven patients were included in the study. Pulmonary hypertension was suspected in 15 patients; five patients had chronic thromboembolic pulmonary hypertension confirmed by ventilation-perfusion lung scintigraphy, right heart catheterization and pulmonary angiography. Two patients with clinical class functionally advanced underwent surgical pulmonary endarterectomy and two asymptomatic patients underwent medical treatment. The prevalence of undiagnosed chronic thromboembolic pulmonary hypertension was 4.5%. Chronic thromboembolic pulmonary hypertension is a serious disease with a poor prognosis if not treated early. Surgical treatment is decisive. After surgery, the majority of patients have a substantial improvement in their functional status and in haemodynamic variables. Many patients are asymptomatic. Implementation of screening programmes may be helpful for an early diagnosis and early proper therapy.