Pulmonary Artery Denervation Effective for PAH

MIAMI BEACH, FLA.—A prospective first-in-man study conducted at a single center in China found that denervation of the pulmonary artery is safe and feasible as a treatment for pulmonary artery hypertension and could improve functional capacity and hemodynamic parameters in patients who fail to respond to standard medications.

Shao-Liang Chen, MD, of Nanjing Medical University in China, presented the results from the PADN-1 trial at TCT 2012. “We report for the first time the significant improvement of functional capacity and hemodynamic parameters following pulmonary artery denervation in patients with pulmonary artery hypertension who are unresponsive to medications,” he said.

Based on successful animal test studies in which denervation alleviated effects of balloon occlusion, Chen and colleagues designed a pulmonary denervation system where a catheter is fitted with 10 electrodes on its tip. To denervate an area of the pulmonary artery around its bifurcation, pulses of no more than 10 watts for a period of about 60 seconds are used at each of the 10 electrodes in turn. In the current study, the researchers tested the safety and efficacy of this system in a small group of patients who were unresponsive to medication. Those who received denervation (n = 13) were compared with a control group of patients who refused the therapy (n = 8).

Pulmonary denervation effective

The therapy had a clear effect on pulmonary artery pressure, with drops occurring immediately that were sustained out through 3 months (see Figure).

PAD FigureIn the denervation patients only, the trans-pulmonary pressure gradient dropped from 33 mm Hg at baseline to 23 mm Hg at 3 months (P<.001). The pulmonary artery occlusion pressure did not change significantly (19 mm Hg at baseline vs. 15 mm Hg at 3 months P=.281). There was also a drop in N-terminal B-type natriuretic peptide (NP-BNP) in the denervation patients that remained over the 3-month follow-up.

Functional capacity assessments also suggested denervation therapy was effective. Six-minute walk distance rose from 354 meters at baseline to 449 meters at 1 month and 455 meters at 3 months in denervation patients. In control patients, the 6-minute walk distance stayed largely the same at 1 and 3 months. WHO class fell from 3.6 to 1.6 at 3 months in denervation patients; in control patients, WHO class was 3.5 at baseline and 3.2 at 3 months. One patient in each group died. No denervation patients required rehospitalization, while six control patients (75%) were rehospitalized within 1 month of the study’s initiation.

Disclosures
  • Dr. Chen reports no relevant conflicts of interest.

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