Improvement of right ventricular dysfunction after pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension: utility of echocardiography to demonstrate restoration of the right ventricle during 2-year follow-up

Background: Pulmonary endarterectomy (PEA) is an effective treatment for chronic thromboembolic pulmonary hypertension (CTEPH) by dissecting the residual thrombus from the native vessel wall. The goal of PEA is to improve pulmonary hemodynamics and right ventricular dysfunction, and thus increase exercise capacity, alleviate symptoms and decrease mortality. The aim of this study, accordingly, was to assess the ability of echocardiography to provide a mechanism to monitor the time course of RV functional improvement after PEA.

Methods: Twenty-six consecutive adult patients who underwent PEA for CTEPH were included in the study. All the patients underwent transthoracic echocardiography and right heart catheterization before surgery. Follow-up echocardiography was performed within 3, 12, and 24 months of surgery. The parameters of right ventricle were compared with baseline data.

Results: In all cases, the RV was enlarged and systolic function was impaired before surgery. RV systolic pressure fell from 92±16 mm Hg before surgery to 41±9 mm Hg by the 3 month post-PEA follow-up (P<0.001). RV end-diastolic area and end-systolic area likewise decreased from 35.8±4.4 cm(2) to 26.6±4.8 cm(2) (P<0.001) and from 27.1±3.8 cm(2) to 17.9±3.8 cm(2) (P<0.001), respectively. The RV myocardial performance index also decreased from a ratio of 0.8±0.1 to 0.5±0.1 (P<0.001). The tricuspid annular plane systolic excursion increased from 8.8±0.6mm to 10.1±0.9 mm (P<0.001). Tricuspid regurgitation (TR) improved from a mean grade of 3.1±0.5 to 2.2±0.7 (P<0.001). At the 12 and 24 month follow-up examinations, RV systolic pressure and function remained improved, respectively. The RV systolic pressure remained above 50 mmHg in only two cases.

Conclusion: In patients with CTEPH who undergo PEA, echocardiography is a useful tool for the evaluation of RV function. Echocardiographic measurements of RV size, systolic pressure, systolic function, and TR show significant improvement, and this effect is sustained for up to 24 months after surgery.