18th January 2024

Scleroderma Pulmonary Hypertensive Crisis

Pulmonary arterial hypertension (PAH) in systemic sclerosis is a rare but potentially fatal complication. It may occur either as a primary process or secondary to pulmonary fibrosis. Early clinical symptoms of PAH are non-specific, including breathlessness, light-headedness, syncope, fatigue and weakness. Patients should be screened at the time of diagnosis and annually thereafter. However, some patients may go unscreened, particularly if they develop a compensatory sedentary lifestyle which limits symptoms. In these patients, PAH may progress for some time and become quite severe before it is detected.

The gold standard diagnostic tool is right heart catheterisation. Patients can sometimes present acutely, and, in this case, it will be diagnosed on an echo doppler of the heart.

Clinical signs associated with PAH

• Split heart sounds with a loud P₂
• Tricuspid regurgitation (systolic murmur)
• Parasternal heave
• Raised JVP
• Ascites
• Hepatomegaly with a pulsatile liver
• Peripheral oedema

Pathophysiology

In primary pulmonary arterial hypertension, vasospasm and intimal proliferation with fibrin deposition in the lungs lead to vascular resistance and remodelling, which ultimately results in right ventricular dysfunction.

Management

Management revolves around targeting these pathways to restore the balance between vasoconstriction and vasodilation. Thus, vasodilators (nitric oxide and prostacyclin) and proliferative mediators (endothelin-1) are targeted using the following medications:

• Prostacyclin analogues, e.g. Epoprostenol, Iloprost
• Endothelin-receptor antagonists, e.g. Bosentan
• Phosphodiesterase Type-5 Inhibitors (which increase nitric oxide production), e.g. Sildenafil

In the acute setting, patients can present significantly hypoxic and, require IV prostacyclin, and may require advanced respiratory support for oxygenation. Respiratory involvement in systemic sclerosis, either pulmonary fibrosis or PAH, is the most common cause of death for patients living with this condition.