Outcome of Surgery for Chronic Thromboembolic Pulmonary Disease without Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a serious condition that results from incomplete resolution of thromboemboli in pulmonary arteries. Symptomatic patients with chronic thromboembolic disease may have normal hemodynamic at rest. The aim of this study is to evaluate the outcome of pulmonary endarterectomy (PEA) in symptomatic patients with chronic thromboembolic pulmonary disease (CTEPD) in the absence of pulmonary hypertension as currently defined (mean pulmonary artery pressure [mPAP] < 20 mm Hg).

Here, we report four symptomatic patients with chronic thromboembolic and normal hemodynamic at rest (mPAP ≤20 mm Hg or 20 < mPAP < 25 mm Hg and pulmonary vascular resistance [PVR] < 240 dyn·s/cm⁵) who underwent PEA between September 2015 and September 2019. The main outcome measures were functional New York Heart Association class, 6-minute walk distance (6MWD), hemodynamic measures in right heart catheterization (RHC), morbidity, and mortality.

There were significant improvement in function class (2.6 ± 0.54 vs. 1 ± 0.2, p = 0.00), mPAP (preoperative: 23.3 ± 0.5 mm Hg vs. postoperative: 18.6 ± 1.5 mm Hg, p = 0.02), 6MWD (preoperative: 378.2 ± 68.7 m vs. postoperative: 432.9 ± 44.5 m, p = 0.01), and PVR (215.33 ± 91 vs. 101 ± 32 dyn·s/cm⁵, p = 0.1) 6 months after surgery based on data from RHC which was done during exercise. Also, RHC showed a significant decrease in mPAP (preoperative: 37 ± 7.7 mm Hg vs. postoperative 28 ± 3.2 mm Hg, p = 0.06).

PEA could improve function class and hemodynamic in patients with CTEPD. Considering hemodynamic improvement in this group of patients after PEA, definition of CTEPH may need to be revised.