The protective effects of radiofrequency pulmonary artery denervation on the progression of chronic thromboembolic pulmonary hypertension

This study aimed to assess the safety and efficacy of radiofrequency pulmonary artery denervation with the Simplicity system in patients with distal chronic thromboembolic pulmonary hypertension.

60 chronic thromboembolic pulmonary hypertension patients with mean pulmonary artery pressure >25 mm Hg and absence of proximal artery lesion defined by pulmonary angiography were randomized into 2 groups. Group 1 included 30 patients who underwent pulmonary artery denervation procedure. The other 30 patients were assigned to the control group (only angio plus right heart catheterization). The procedure of pulmonary artery denervation was performed at the lateral wall of main pulmonary artery and ostium of the left and right pulmonary arteries using the electrode from Simplicity denervation system. The programmed ablation parameters were temperature >50°C and time = 120 s. Using the coronary guiding technique, the tip of electrode was applied at each spot rotating the tip with pace of 2 mm. The success was defined by decrease of mean pulmonary artery pressure >10%, absence of complications. The primary end point was comparison of mean pulmonary artery pressure change from baseline to 12 months in pulmonary artery denervation group compared with change from baseline to 12 months in control group. The secondary point was change in 6-min walk distance and pulmonary vascular resistance at the 12-month follow-up.

There were no complications after pulmonary artery denervation. The hemodynamic success was achieved in 93% of all cases. The mean number of radiofrequency applications to achieve success was 10.3 per patient. During follow-up period 3 patients died in pulmonary artery denervation group: (1 died of gastro-intestinal bleeding, 2 – of right ventricular failure) and 3 patients in control group. The mean decreases in the mean pulmonary artery pressure were 8.7 mm Hg in the pulmonary artery denervation group and 3.1 mm Hg in control group (p<0.05). After pulmonary artery denervation in comparison with the control group was observed significant decrease in pulmonary vascular resistance (8.3±2.8 WU vs. 11.2±3.7). 6-min walk distance significantly increased by 81 m after pulmonary artery denervation and 29 m in control group (p<0.05). This improvement was associated with significant improvements in the WHO functional class.

The usage of the Simplicity denervation system in pulmonary artery denervation procedure is safe and effective. Further studies are required to determine the role of pulmonary artery denervation in the treatment of chronic thromboembolic pulmonary hypertension. The next step of pulmonary artery denervation development will be the use of this method combined with recommended treatment (medical therapy, pulmonary endarterectomy and balloon pulmonary angioplasty) as additional option, that may sufficiently improve outcomes in some patients

Type of funding source: None