Ultrasound pulmonary denervation reduces pulmonary vascular resistance in PAH
Among patients with pulmonary artery hypertension, intravascular ultrasound pulmonary artery denervation was associated with reductions in pulmonary vascular resistance and increases in 6-minute walk distance and daily activity, according to an early feasibility study published in JACC: Cardiovascular Interventions.
“Patients with pulmonary hypertension show signs of increased sympathetic nerve activity and early studies have suggested that targeting this may provide benefit to patients,” Alex Rothman, BM BCh, PhD, consultant cardiologist and Wellcome Trust Fellow at the University of Sheffield and Sheffield Teaching Hospitals NHS Trust in the United Kingdom, wrote in an email to Healio Pulmonology.
Consequently, Rothman and colleagues conducted the international, open-label, multicenter TROPHY1 study. It included 23 patients (mean age, 60 years; 78% women; 83% white) with PAH on a minimum of dual oral therapy recruited from eight specialist pulmonary hypertension centers in Europe, Israel and the United States. All patients underwent intravascular ultrasound pulmonary denervation (TIVUS System, SoniVie) after qualifying for right heart catheterization and were to remain on disease-specific medication throughout the study. Safety and efficacy endpoints of interest included procedure-related adverse events at 30 days and change in pulmonary hemodynamic status, 6-minute walk distance and quality of life from baseline to 4 or 6 months, respectively.
On average, patients received 10 ultrasound activations and the duration of the procedure was 32 minutes with a mean fluoroscopy time of 8.1 minutes.
No procedure-related serious adverse events occurred, according to the data. Additionally, the researchers received no reports of procedure-related pain lasting longer than 2 days and no perforation, dissection, aneurysm or stenosis was evident on post-procedure pulmonary angiography, MRI or CT at 1 and 12 months.
In terms of efficacy, three patients did not undergo right heart catheterization and were therefore excluded from the analysis. Results showed improvements in hemodynamic and functional endpoints at 4 or 6 months, including a 17.8% reduction in pulmonary vascular resistance (94 dyn/s/cm–5; P = .001), a 42-m increase in 6-minute walk distance (P = .002) and a 671-step increase (P = .04) in daily activity. Pulmonary artery pressure (–5.1 mm Hg; P < .01), right atrial pressure (–2.4 mm Hg; P = .01) and pulmonary arterial compliance (0.39 mL/mm Hg; P < .01) also improved.
However, the researchers found no differences from baseline to 4 or 6 months in cardiac output, stroke volume index, quality of life, N-terminal pro-brain natriuretic peptide, systemic blood pressure and heart rate.
“The study showed that in patients with PAH, ultrasound pulmonary artery denervation was both feasible and safe. Patients were established on best medical therapy and the improvements in measures of disease severity, exercise capacity and activity provide promise for further studies,” Rothman told Healio Pulmonology.
Looking ahead, he added that further sham-controlled studies are necessary to yield more evidence on the procedure’s efficacy. – by Melissa Foster
For more information:
Alex Rothman, BM BCh, PhD, consultant cardiologist and Wellcome Trust Fellow at the University of Sheffield and Sheffield Teaching Hospitals NHS Trust in the United Kingdom, can be reached at firstname.lastname@example.org; Twitter: @alex_rothman.
Disclosures: This study was funded by SoniVie. Rothman reports he has financial ties with Abbott, Actelion, Endotronix, Medtronic, MRC, Novartis, SoniVie and Wellcome Trust. Please see the study for all other authors’ relevant financial disclosures.