Secondary pulmonary arterial hypertension (SPAH) is an adverse outcome of a variety of systemic disorders. These include collagen vascular diseases, chronic thromboembolism, human immunodeficiency virus (HIV), portal pulmonary hypertension and other diseases. Progression of SPAH may persist despite stabilization of the causative disease and contributes to the poor quality of life and unfavorable survival in these patients. Treatment of the underlying cause and oxygen supplementation may alleviate symptoms, but no specific therapy to treat SPAH currently exists. Endothelin receptor blockade with bosentan has been shown to be beneficial therapy in the treatment of primary pulmonary hypertension but efficacy of this therapy in SPAH has not been established.
Retrospective review of patients followed through our clinic.
We describe a case series of six patients with disparate causes of SPAH, who benefited from endothelin receptor blockade therapy. The causes of SPAH in this series included collagen vascular disease (scleroderma 1, systemic lupus erythematosis 2), chronic thromboembolic disease (2) and granulomatous vasculitis from sarcoidosis (1). Therapy with bosentan led to symptomatic improvement, shift in New York Heart Association functional class and walking distance in all patients. 6 minute walk test demonstrated an increase from a mean of 151.67±69.30 meters at baseline to 314.83±89.09 meters following average 14 months of bosentan treatment. Pulmonary arterial pressure decreased in most but not in all six patients on follow up echocardiogram.
The patients in this series very likely improved secondary to the antiproliferative effects of bosentan on pulmonary vasculature.These patients were treated with multiple therapies including calcium channel blocker and anticoagulation. Although, calcium channel blockers and anticoagulation may have contributed to the therapeutic effect in these patients, they have not been shown to improve exercise capacity or functional class in advanced pulmonary hypertension.
This case series makes a compelling argument for a systematic, controlled study of endothelin receptor antagonists in patients with SPAH.
Satyendra Sharma, None.