The Prospective Risk Factor Evaluation & Discovery In CTEPH Study

This research study wants to find markers in the blood that may help to predict a patient's future risk of developing a disease called CTEPH. The study also wants to see if active monitoring for signs and symptoms of CTEPH after a pulmonary embolism (a blood clot in the lungs) can improve the diagnosis of CTEPH. Patients who enroll in this study will have periodic blood draws and clinic and/or phone follow-up to monitor for signs and symptoms of CTEPH. Patients' medical records will also be reviewed for information related to pulmonary embolisms and/or CTEPH.