Chronic thromboembolic pulmonary hypertension: Initial experience of patients undergoing pulmonary thromboendarterectomy.

Introduction And Objectives: Pulmonary endarterectomy (PEA) is a potentially curative procedure in patients with chronic thromboembolic pulmonary hypertension (CTEPH). This study reports the initial experience of a Portuguese PH center with patients undergoing PEA at an international surgical reference center.

Methods: Prospective observational study of consecutive CTEPH patients followed at a national PH center, who underwent PEA at an international surgical reference center between October 2015 and March 2019. Clinical, functional, laboratory, imaging and hemodynamic parameters were obtained in the 12 months preceding the surgery and repeated between four and six months after PEA.

Results: 27 consecutive patients (59% female) with a median age of 60 (49-71) years underwent PEA. During a median follow-up of 34 (21-48) months, there was an improvement in functional class in all patients, with only one cardiac death. From a hemodynamic perspective, there was a reduction in mean pulmonary artery pressure from 48 (42-59) mmHg to 26 (22-38) mmHg, an increase in cardiac output from 3.3 (2.9-4.0) L/min to 4.9 (4.2-5.5) L/min and a reduction in pulmonary vascular resistance from 12.1 (7.2-15.5) uW to 3.5 (2.6-5,2) uW. During the follow-up, 44% (n=12) of patients had no PH criteria, 44% (n=12) had residual PH and 11% (n=3) had PH recurrence. There was a reduction of N-terminal pro-B-type natriureticpeptide from 868 (212-1730) pg/mL to 171 (98-382) pg/mL. Rright ventricular systolic function parameters revealed an improvement in longitudinal systolic excursion and peak velocity of the plane of the tricuspid ring from 14 (13-14) mm and 9 (8-10) cm/s to 17 (16-18) mm and 13 (11-15) cm/s, respectively. Of the 26 patients with preoperative right ventricular dysfunction, 85% (n=22) recovered. The proportion of patients on specific vasodilator therapy decreased from 93% to 44% (p<0.001) and the proportion of those requiring oxygen therapy decreased from 52% to 26% (p=0.003). The six-minute walk test distance increased by about 25% compared to the baseline and only eight patients had significant desaturation during the test.

Conclusion: Pulmonary endarterectomy performed at an experienced high-volume center is a safe procedure with a very favorable medium-term impact on functional, hemodynamic and right ventricular function parameters in CTEPH patients with operable disease. It is possible for PH centers without PEA differentiation to refer patients safely and effectively to an international surgical center in which air transport is necessary.