Patients with pulmonary arterial hypertension (PAH) receiving combination therapy with intravenous (IV) PGI2 may suffer from greater disease burden compared with those receiving monotherapy or combination therapy, excluding IV PGI2.

Researchers from Massachusetts General Hospital and Novartis Pharma AG in Switzerland performed statistical tests on 446 patients with PAH, of which (a) 337 were receiving monotherapy; (b) 88 were receiving non-IV PGI2 combination therapy; and (c) 21 were receiving IV PGI2 .

Results showed that pulmonary vascular resistance, mean number of PAH-related hospitalizations, and dyspnea scores were highest in those treated with IV PGI2.

This study was presented during CHEST 2012, the annual meeting of the , held October 20 – 25, in Atlanta, Georgia.