Stephan Moll, MD writes…
On Oct 8th, 2013 the FDA approved Adempas® (riociguat), a new oral drug to treat pulmonary hypertension. The drug is a guanylate cyclase stimulator that leads to arteries dilatation. It is intended for:
- Patients with chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary endarterectomy surgery or patients who cannot undergo surgery, to improve exercise tolerance; and
- Patients with pulmonary arterial hypertension (PAH) of unknown causes.
It is taken orally three times a day. The FDA approval came based on 2 sentinel phase 3 studies, published in 2013 in the N EJM [ref 1,2]. The FDA release is here. The drug should / will be prescribed by physicians in pulmonary hypertension clinics. Such specialized pulmonary hypertension clinics alrady exist and there is an effort under way on a national level to designate appropriate clinics as “Pulmonary Hypertension Comprehensive Care Centers” (details here) – to be launched in 2014 – as an activity of the Pulmonary Hypertension Association (web link here).
Pulmonary hypertension after PE
The current hemodynamic definition is a mean pulmonary artery pressure of > 25 mm Hg by right heart catheterization, with normal pulmonary capillary wedge pressure, left atrial pressure, or left ventricular end-diastolic pressure. It typically occurs within the first 2 years after a PE, affecting 3.8 % of PE patients.
In a patient with a history of large PE or significant residual shortness of breath, the following screening for pulmonary hypertension (chronic thromboembolic pulmonary hypertension = CTEPH) is appropriate:
- Pulse oximetry at rest and after climbing stairs (or formal 6 min walk test in a pulmonary function laboratory);
- Cardiac echo with focus on right heart and estimation of pulmonary artery pressure;
- VQ scan to look for chronic PE – CTA of the chest is NOT sensitive for chronic PE;
- Right heart catheterization with pulmonary artery pressure measurements and pulmonary arteriography if any of the aforementioned screening tests raise the suspicion for presence of pulmonary hypertension.
- Ghofrani HA et al. Riociguat for the treatment of chronic thromboembolic pulmonary hypertension. N Engl J Med 2013;369:319-329.
- Ghofrani HA et al. Riociguat for the treatment of pulmonary arterial hypertension. N Engl J Med 2013;369:330-40.
I have no financial conflict of interest.
Last updated: Oct 16th, 2013