An algorithm comprising an assessment of CTEPH probability (risk factors and symptoms), ECG criteria, NT-pro-BNP, and echocardiography was able to diagnose CTEPH with a sensitivity and specificity of 85% and 100%, respectively, (PPV: 100%; NPV: 100%) 4 months post-PE [54]. Here, NPPB is linked to chronic thromboembolic pulmonary hypertension.