**5. Clinical presentation**

measure the right-sided pressures at rest and after supine bicycle ergometry exercise. At rest, the pulmonary artery (PA) mean pressure and the pulmonary vascular resistance (PVR) were significantly higher in the heparin group compared with the thrombolytic group (22 vs. 17 mmHg, p<0.05, and 351 vs. 171 dynes s (-1) cm (-5), p<0.02, respectively). During exercise both parameters rose to a significantly higher level in the heparin group (from rest to exercise, PA: 22-32 mmHg, p<0.01; PVR: 351-437 dynes s (-1) cm 5, p<0.01, respectively), but not in the thrombolytic group (rest to exercise, PA: 17-19 mm Hg, p = NS; PVR: 171-179 dynes s (-1) cm (-5), p = NS). Thus, thrombolytic therapy preserves the normal hemodynamic response to exercise in the long-term and may prevent the development of pulmonary hypertension [34].

In patients with CTEPH, lifelong anticoagulation is indicated I C

**Recommendation Class of recommendation Level of evidence**

I C

I C

IIa C

IIa C

IIb C

The diagnosis of CTEPH is based on the presence of pre-capillary PH (mean PAP ≥25 mmHg, PCWP ≤15 mmHg, PVR "/>2 Wood units) in patients with multiple chronic/organized occlusive thrombi/emboli in the elastic pulmonary arteries (main, lobar,

Surgical pulmonary endarterectomy (PEA) is the recommended

Once perfusion scanning and/or CT angiography shows signs compatible with CTEPH, the patient should be referred to a center

**Table 2.** Recommendations of the ESC/ERS guidelines for CTEPH [93].

with expertise in surgical pulmonary endarterectomy.

The selection of patients for surgery should be based on the extent and location of the organized thrombi, on the degree of PH, and

PAH-specific drug therapy may be indicated in selected CTEPH patients such as patients who are not candidates for surgery or patients with residual PH after pulmonary endarterectomy.

segmental, subsegmental), persisting after effective anticoagulation over a minimum period of three months.

treatment for patients with CTEPH.

146 Pulmonary Hypertension

on the presence of co-morbidities.

CTEPH may be related to a disorder of hemostasis such as elevated levels of factor VIII. The expression of plasminogen activator inhibitor (PAI-1) of type 1 was found to be higher in patients monitored for CTEPH [30, 35, 36]. Abnormalities in the structure of fibrinogen and function were also observed in other series. Traditional risk factors for venous thromboemb‐ olism (VTE) include antithrombin deficiency, protein C deficiency, protein S deficiency, factor V Leiden, plasminogen deficiency, and anticardiolipin antibodies [26]. However, in 147 consecutive patients with CTEPH, the prevalence of hereditary thrombotic risk factors was not increased when compared to 99 consecutive patients with IPAH or to 100 control patients.

Generally, the clinical history is not helpful in the diagnosis of CTEPH.. Indeed, up to half of patients with CTEPH have no documented history of pulmonary embolism [50]. In one series, 63% of patients had no specific history of acute venous thromboembolism [51]. Therefore, the clinical index of suspicion has been clarified below. The Hispanic clinic has an important place in the diagnosis. It identifies clinical events that could be compatible with an unidentified acute venous thromboembolism [52, 53]. Symptoms of CTEPH are very similar to many other etiologies of pulmonary arterial hypertension. The majority of patients who displayed CTEPH were past the age of 60. The symptoms often occurred insidiously and were often attributed to other cardiac comorbidities, obesity or an underlying lung disease [54]. Dyspnea and fatigue were the symptoms most frequently encountered. Patients may present with exertional angina, presyncope, syncope and lower extremity edema. Chest pain may be caused by right ventric‐ ular ischemia. Syncope is an alarming symptom that raises concerns of advanced heart failure and should prompt urgent examination.

concomitant diseases, and finally determine eligibility for pulmonary endarterectomy

Chronic Thromboembolic Pulmonary Hypertension

http://dx.doi.org/10.5772/54749

149

After a thorough history and physical exam, patients with suspicious symptoms or signs of pulmonary hypertension and a history of pulmonary embolism or pulmonary hypertension of unknown cause should be investigated to confirm or exclude the diagnosis of CTEPH [64]. Imaging is central to making the diagnosis and management of CTEPH, but which test do you use, and when? The imaging algorithm used at Papworth Hospital for CTEPH diagnosis is shown in Figure 1. Echocardiography is used in the initial assessment of suspected pulmonary hypertension. V/Q lung scanning may be used to differentiate chronic thromboembolic

**Figure 1.** Diagnostic imaging algorithm for chronic thromboembolic pulmonary hypertension (CTEPH). CT: computed tomography; MR: magnetic resonance.: pulmonary angiography is usually performed in conjunction with right heart catheterisation and should be performed at centres experienced with CTEPH and pulmonary endarterectomy [20].

Transthoracic echocardiography with Doppler imaging is a sensitive exam for the detection of pulmonary hypertension and right ventricular dysfunction, but it is not specific for the

pulmonary hypertension from other causes of pulmonary hypertension.

(PEA) or medical treatment.

**7.1. Echocardiography**
