Circulating big endothelin-1: An active role in pulmonary thromboendarterectomy?

Pulmonary thromboendarterectomy is an effective treatment for patients with chronic thromboembolic pulmonary hypertension. The early postoperative course may be associated with pulmonary vasoconstriction and profound systemic vasodilation. We investigated the potential involvement of endothelins in these hemodynamic alterations. Seventeen patients with chronic thromboembolic pulmonary hypertension (pulmonary vascular resistance, 1015 ± 402 dyne · s · cm −5 [mean ± SD]) underwent pulmonary thromboendarterectomy with cardiopulmonary bypass and deep hypothermic circulatory arrest. Peripheral arterial blood samples were drawn before sternotomy, during cardiopulmonary bypass before and after deep hypothermic circulatory arrest, and 0, 8, 16, and 24 hours after surgery and were analyzed for big endothelin-1. The patients were divided into 2 groups according to whether their preoperative big endothelin-1 plasma level was above or below the cutoff point of 2.1 pg/mL, as determined by receiver operating characteristic curve analysis (group A, big endothelin-1