In pulmonary arterial hypertension, right heart function is the most important indicator of prognosis (PAH). As we will show in this post, there are currently no medicines available that directly target the right ventricle.
When analysed using the pump-function graph, a meta-analysis of clinical trials in PAH found that current PAH treatment appears to have minimal cardiac-specific effects. We investigated the clinical potential of left heart failure (LHF) therapy for PAH based on currently available data, driven by the idea that "left" and "right" heart failure may share fundamental underlying pathophysiological mechanisms.
The sympathetic nervous system and the renin–angiotension–aldosterone system are both significantly active in PAH, just as they are in LHF. We know from LHF that interfering with this process, such as by inhibiting angiotensin-converting enzyme or blocking b-blockade, is helpful in the long run. As a result, these drugs may be effective in the treatment of PAH. In addition, implantable cardioverter-defibrillators may minimise the risk of sudden cardiac death in PAH patients. Finally, pilot trials have shown that interventricular dyssynchrony, which is common in end-stage PAH, can benefit from cardiac resynchronization therapy.
Finally, treatments for LHF could be useful in the treatment of PAH. However, before they can be used to treat PAH, they must first be tested for safety and efficacy in well-designed clinical trials.