Time course of restoration of systolic and diastolic right ventricular function after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

Abstract

Background: In chronic thromboembolic pulmonary hypertension, right ventricular (RV) pressure overload causes RV remodeling and dysfunction. Successful pulmonary endarterectomy (PEA) initiates restoration of RV remodeling and global function. Little is known on the restoration of systolic and diastolic RV function. Using transthoracic echocardiography, we studied the time course and extent of postoperative restoration of systolic and diastolic RV function.

Methods: In chronic thromboembolic pulmonary hypertension (n = 55, 36 women, age 52 ± 14 years), transthoracic echocardiography was performed before PEA (pre-PEA) and 2 weeks, 3 months, and 1 year postoperatively.

Results: Two weeks postoperatively, RV afterload and dimension had decreased significantly, without further improvement during follow-up. Global RV function, expressed by the myocardial performance index, showed a gradual improvement (from pre-PEA 0.58 ± 0.29 to 0.45 ± 0.38, 0.39 ± 0.19, and 0.37 ± 0.18). In contrast, 2 weeks after PEA systolic RV function, as assessed by tricuspid annular plane systolic velocity excursion and peak tricuspid annular systolic velocity of the RV, had worsened, with a subsequent incomplete restoration during follow-up: tricuspid annular plane systolic velocity excursion from 19.3 ± 5.0 to 12.4 ± 2.5, 15.3 ± 3.0, and 16.8 ± 2.9 mm and systolic velocity of the right ventricle from 11.4 ± 3.0 to 9.6 ± 2.0, 10.0 ± 1.8, and 10.3 ± 1.7 cm/s. Postoperative diastolic RV function also showed a biphasic response: tricuspid inflow-to-annulus ratio from 6.1 ± 3.0 to 9.5 ± 3.5, 6.8 ± 2.4, and 6.3 ± 2.2 cm/s. Dynamics and ultimate level of restoration of systolic and diastolic RV function were similar in patients with and without residual pulmonary hypertension.

Conclusions: Postoperative reduction in RV afterload caused an immediate improvement in RV dimension and global function. In contrast, systolic and diastolic RV function deteriorated after PEA with subsequently a gradual yet incomplete restoration during 1-year follow-up.