Contrast pulmonary artery （PA) angiography was performed to localize the pulmonary artery bifurcation level and calculate the PA diameter.Once the anatomy was deemed acceptable, the radiofrequency ablation catheter was introduced into ostium of the left PA, ostium of the right PA , and the distal bifurcation area of the main PA.This was then maneuvered within the PA to allow energy delivery in a circumferential manner to ensure that the electrodes were tightly in contact with the endovascular surface. About four to eight ablations at 10 W for 60 seconds each were performed in ostium of the left PA, ostium of the right PA , and the distal bifurcation area of the main PA.

Patients in the standard treatment group will take their baseline anti-heart failure medications at the original doses, without any changes except when medically required.The anti-heart failure drugs treatment is consistent in both arms.

Contrast pulmonary artery （PA) angiography was performed to localize the pulmonary artery bifurcation level and calculate the PA diameter.Once the anatomy was deemed acceptable, the radiofrequency ablation catheter was introduced into the distal bifurcation area of the main PA.This was then maneuvered within the PA to allow energy delivery to ensure that the electrodes were tightly in contact with the endovascular surface. About two to three ablations at 1-15 W for 240 seconds each point were performed in the distal bifurcation area of the main PA.

The primary effectiveness endpoint is change in 6-min-walk distance (6-MWD) from baseline to 6 months post-randomization.

Measure pulmonary vascular resistance using 2D doppler echocardiogram w/definity. Correlation coefficients between the technique above the the gold standard right heart catheterization measures of pulmonary vascular resistance.

The safety endpoint is the accuracy of pulmonary embolism (PE). Suspected PE with one of the following:

1. new intra-luminal filling defect on CT scan, MRI scan, or pulmonary angiogram;
2. new perfusion defect of at least 75% on V/Q lung scan;
3. inconclusive spiral CT, pulmonary angiography or lung scan with demonstration of deep vein thrombosis in the lower extremities by venography

Fatal PE is:

1. PE based on objective diagnostic testing or autopsy or
2. death not attributed to a documented cause and for which deep vein thrombosis/PE cannot be ruled out.