Methods. Fifty patients aged 52±10 with mitral valve disease complicated severe PAH (mean PAP > 40mm Hg) were randomly assigned to mitral valve surgery with or without PA ablation procedure. Eligible criteria: positive reactive test with nitric oxide inhalation (decrease of mean PAP more than 10 mm Hg without decrease of cardiac output). There were no between group differences in preoperative characteristics.
Surgical procedure: After bypass is establishedthe fibrous fold of pericardiumand the ligamentum arteriosum are dissected out, and the branches of the right and left pulmonary artery are mobilized well out into the hilum of the lungs bilaterally. PA ablation was performed epicardially at the bifurcation of the main PA, and 10 mm distal to the right and left PA’s using AtriCure Isolator®multifunctional pen.
Serial assessment of echocardiography, right heart catheterization (catheter Swan-Ganz), and 6-min walk test (6MWT) were performed during hospital stay. The primary endpoints were the change of meanpulmonary artery pressure (PAP)and 6MWT. The secondary endpoints were hospital mortality, freedom from PADN-related complication: PA perforation, PA dissection, and PA thrombosis (MDCT assessment).
Results. There were no early deaths. No procedure-related complications were observed.
On first day after surgery patients from ablation group showed significant reduction of mean PAP (from 50.6±5.3to 34.6±9.9 mm Hg, p<0.001), and significant improvement of 6MWT at discharge (from 229±34 m to 475±21 m, p<0.001). On first day after surgery patients from control group also showed significant reduction of mean PAP (from 51.3±6.3to 47.2±8.5 mm Hg, p=0.011), and significant improvement of 6MWT at discharge (from 249±32 m to 335±18 m, p<0.001). Nevertheless, there was significant between group difference in mean PAP on first day after surgery (34.6±9.9 mm Hg, vs 47.2±8.5 mm Hg,p = 0.005). Moreover there was significant differences in 6MWT at discharge (475±21 m vs 335±18 m, p = 0.002) with benefit to ablation group.
Conclusions. We report for the first time the effect and superiority of PA ablation on functional capacity and hemodynamics in patients with mitral valve disease complicated PAH. Epicardial PA ablation for the treatment PAH can be effectively and safely performed during open heart surgery.