Intravascular Ultrasound Pulmonary Artery Denervation to Treat Pulmonary Arterial Hypertension (TROPHY1): Multicenter, Early Feasibility Study.

OBJECTIVES: The aim of this study was to investigate whether therapeutic intravascular ultrasound pulmonary artery denervation (PDN) is safe and reduces pulmonary vascular resistance (PVR) in patients with pulmonary arterial hypertension (PAH) on a minimum of dual oral therapy. BACKGROUND: Early studies have suggested that PDN can reduce PVR in patients with PAH. METHODS: TROPHY1 (Treatment of Pulmonary Hypertension 1) was a multicenter, international, open-label trial undertaken at 8 specialist centers. Patients 18 to 75 years of age with PAH were eligible if taking dual oral or triple nonparenteral therapy and not responsive to acute vasodilator testing. Eligible patients underwent PDN (TIVUS System). The primary safety endpoint was procedure-related adverse events at 30 days. Secondary endpoints included procedure-related adverse events, disease worsening and death to 12 months, and efficacy endpoints that included change in pulmonary hemodynamic status, 6-min walk distance, and quality of life from baseline to 4 or 6 months. Patients were to remain on disease-specific medication for the duration of the study. RESULTS: Twenty-three patients underwent PDN, with no procedure-related serious adverse events reported. The reduction in PVR at 4- or 6-month follow-up was 94 ± 151 dyn·s·cm-5 (p = 0.001) or 17.8%, which was associated with a 42 ± 63 m (p = 0.02) increase in 6-min walk distance and a 671 ± 1,555 step (p = 0.04) increase in daily activity. CONCLUSIONS: In this multicenter early feasibility study, PDN with an intravascular ultrasound catheter was performed without procedure-related adverse events and was associated with a reduction in PVR and increases in 6-min walk distance and daily activity in patients with PAH on background dual or triple therapy.