Objective Investigate the influence of the sympathetic denervation of the pulmonary trunk and the orifices of the pulmonary arteries on the degree of pulmonary hypertension (PH) and outcomes of the surgical treatment of atrial fibrillation (AF) in patients with mitral valve defects, complicated AF, and high PH.Material and methods We analyzed the surgical treatment of 140 patients with mitral valve defect, concomitant AF, and high PH - pulmonary artery systolic pressure (PASP) gradient more than 40 mm Hg. The group of interest included 51 patients (46 patients with severe mitral stenosis and five patients with grade 4 mitral valve regurgitation). All patients underwent mitral valve correction (47 valve replacement surgeries and 4 valve-sparing interventions), biatrial Maze IV procedure, and additionally, denervation of the pulmonary trunk and the orifices of the pulmonary arteries. The control group included 89 patients diagnosed with mitral valve defect, AF, and PH with PASP > 40 mm Hg. However, unlike in patients of interest, denervation of the pulmonary arteries was not performed.Results Circular radiofrequency denervation of the pulmonary trunk and the orifices of the pulmonary arteries using a clamp-destructor is an effective and safe method, significantly reduces secondary PH (p=0.018), promotes reverse remodeling of the heart chambers, left atrium in particular (p=0.01), and improves outcomes of the Maze IV procedure (p=0.022) by restoring sinus rhythm in patients with mitral valve defects, complicated AF, and high PH.Conclusion This technique must be studied further involving a more significant number of patients, analyzing long-term results, and using this technique in patients with non-valvular causes of secondary PH.