Goal of the study is to assess the frequency of pulmonary hypertension in patients with chronic myeloproliferative diseases. In each patient an echocardiography at rest will be performed. In patients without musculoskeletal disease an exercise test (spiroergometry) will be performed. Patients with elevated SPAP at rest or with reduced exercise capacity (peak VO2 < 65%) a right heart catheterization (RHC) will be recommended. Also patients with advanced NYHA functional class (III or IV) or with typical PH findings in electrocardiogram will be advised to undergo a RHC. Additionally for the evaluation of exercise capacity a 6 MWD will be performed.

This work- up of patients allows clinical and hemodynamic evaluation.

Previous small studies and clinical cases have suggested a possible association between pulmonary hypertension (PH) and chronic myeloproliferative disorders (CMPD). MPD may cause PH through different mechanisms as: high cardiac output, asplenia, direct obstruction of pulmonary arteries by megakaryocytes, chronic thromboembolic endothelial pulmonary hypertension (CTEPH), porto-pulmonary hypertension (POPH). However, the exact prevalence of PH in this group of disorders is not known.

This study is designed to identify the pulmonary vascular changes and describe the prevalence of pulmonary hypertension (defined in this study as mean pulmonary arterial hypertension (mPAP) ≥25mmHg as assessed by right-heart catheterization (RHC) or systolic pulmonary arterial pressure (sPAP) ≥37mmHg (2.9 m/s) assessed by echocardiography.

Inclusion Criteria:

• Patients with myeloproliferative disorders
• Written informed consent

Exclusion Criteria:

• Manifest pulmonary hypertension
• Significant pulmonary disease
• Left-sided heart failure or diastolic compliance dysfunction
• Hemodynamic relevant valvular disease
• Systemic arterial hypertension (at rest systolic >150 mmHg, diastolic > 90 mmHg, during exercise > 220 mmHg)
• Severe anemia
• Uncontrolled supraventricular and ventricular arrhythmias
• Myocardial infarction (within the last 12 months)
• Pulmonary embolism (within the last 12 months)
• Recent therapy changes (within the last 12 months)
• Recent major surgeries (within the last 12 months)
• For exercise tests: musculoskeletal diseases which may unable the exercise tests

patients with myeloproliferative disorders