Original Title: Hemodynamic. Functional and Clinical Responses to Pulmonary Artery Denervation with Pulmonary Artery Hypertension of Different Causes. Phase II Results from the Pulmonary Artery Denervation 1 study. Reference: Circ Cardiovasc Interv. 2015;8
Courtesy of Dr. Guillermo Migliaro.
Hospital Alemán, Buenos Aires, Argentina.
The mechanisms responsible for pulmonary artery hypertension (PAH) are multifactorial. PAH reduces survival rates right from the time of diagnosis (86% and 61% at 1 and 5 years, respectively). The effects of different drugs such as endothelial receptor antagonists, phosphodiesterase inhibitors, and prostacyclin analogs, vary according to the cause of PAH and have a limited therapeutic effect on morbidity and mortality.
The sympathetic overactivation and its direct effect on pulmonary vessel contraction play a critical role in PAH pathogenesis. The aim of this study was to assess the hemodynamic functional and clinical response to pulmonary artery denervation (PADN) in patients with PAH of difference causes measured with catheterization and echo doppler testing.
PADN was performed using a dedicated 7-F temperature-sensing ablation catheter according to set parameters of temperature, energy and time in the periconjunctional area between the distal main trunk and the ostial left branch. The study included 66 patients with resting mean all cause pulmonary arterial pressure (PPM) ≥25 mm Hg treated with PADN and prospectively followed up for a year. Target drugs were discontinued after the PADN procedure.
Primary end points included PPM reduction (> 10%), 6 minute walk test tolerance, PAH associated events and death at within 12 months follow up.
94% of patients presented PPM reduction of 7 mm Hg. The average increment in 6-minute walk distance was 94 m. Worse PAH associated events occurred in 15% of patients.
There were 9% PAH associated deaths.
Conclusion
In this group of patients, pulmonary artery denervation was associated to a significant improvement of hemodynamic function, exercise capacity, less frequent PAH associated events and death at 1 year follow up.
Editorial Comment
The present study in phase II included few patients, lacks a control group and does not analyze subgroups; therefore, it remains unclear whether the obtained benefits can be extrapolated to all types of PAH. All procedures were performed by the same operator. Even though outcomes are promising, we should wait for randomized studies to correctly assess them.