Pulmonary Hypertension due to PE: New Drug Approved

 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.

References

1. Ghofrani HA et al. Riociguat for the treatment of chronic thromboembolic pulmonary hypertension. N Engl J Med 2013;369:319-329.
2. Ghofrani HA et al. Riociguat for the treatment of pulmonary arterial hypertension. N Engl J Med 2013;369:330-40.

 

Disclosure

I have no financial conflict of interest.

Last updated:  Oct 16th, 2013