Ambulatory Transition from Parenteral Prostanoid to Inhaled Treprostinil in Patients with Pulmonary Arterial Hypertension

The intravenous or subcutaneous delivery of prostanoid drugs for moderate to severe pulmonary arterial hypertension has been fraught with complications and patient dissatisfaction. Combination therapy including inhaled treprostinil is an attractive alternative in clinically stable patients. Uncertainties exist about the patient characteristics and the optimal setting (inpatient versus office/home) for transition. Sixteen stable patients with pulmonary arterial hypertension and favorable risk profile were transitioned from parenteral prostanoid to combination therapy including inhaled treprostinil in the home setting. Nine patients were using intravenous treprostinil, two patients were using subcutaneous treprostinil, and five patients were using intravenous epoprostenol at a median dose of 80 (interquartile range, IQR 72–90), 76.5 (68 and 85), and 28 (IQR 26–30) ng/kg/min respectively. Patients were followed up for a median of 732.5 days after transition (IQR 506.5–1294 days). Patients tolerated the transition to inhaled treprostinil well without significant change in functional class (81.25% FC I/II before transition vs. 87.5% after), 6-min walk distance [349 m (IQR 226–461 m) to 364 m (IQR 238–565 m), p = 0.09] or NT-proBNP [149 pg/ml (IQR 71.5–383 pg/ml) to 186.5 pg/ml (IQR 83.5–444 pg/ml), p = 0.38]. Hemodynamic data, where available, showed significant improvements in mean pulmonary artery pressure and pulmonary vascular resistance from 36 mmHg (IQR 27–46.5 mmHg) and 5.2 Wood Units (WU) (IQR 3.1–5.6 WU) to 28.5 mmHg (IQR 22–35.5 mmHg) and 3.2 WU (IQR 2.4–4.2 WU) (p-values 0.022 and 0.003). More patients were on triple therapy after transition, and side effects reported were less severe. For select patients, transition from a parenteral prostanoid-based therapy to a combination regimen including inhaled treprostinil in the home setting appears safe and well tolerated.