<International Circulation>:  Today more venous thromboembolism is identified and diagnosed. After progessive treatments， some patients may develop pulmonary thromboembolic hypertension. How do we treat these special patients?

    Prof Wilkins: This is still very much regarded as a surgical disease. In the first instance， the patient needs to be evaluated for potential thromboembolectomy which is a highly skilled technical operation. For those patients who are able to undergo the surgery， they generally do very well as a result. A significant number of patients with chronic thromboembolic pulmonary hypertension are unable to undergo surgery and for these individuals we have a paucity of medical treatments. One of the promising approaches at the moment is a soluble guanylate cyclase activator， which is a drug which seems to augment and replicate the effects of nitric oxide within the pulmonary vasculature. Again， early phase studies have been promising and a late phase III clinical trial is underway. We are hoping this may offer a new treatment for patients who are not surgical candidates.