Endothelin-1 during and after cardiopulmonary bypass: Association to graftsensitivity and postoperative recovery

Objective: Our objectives are 2-fold: (1) to serially measure the release o f endothelin and graft-conduit endothelin sensitivity during and after coro nary artery bypass grafting and (2) to define potential relationships of ch anges in endothelin levels to perioperative parameters. Methods: Endothelin plasma content was measured in patients (n = 105) under going bypass grafting from select vascular compartments before operations a nd at specific intervals up to 24 hours postoperatively. Endothelin sensiti vity was determined in isolated internal thoracic artery segments. Results: Systemic arterial and pulmonary arterial endothelin levels were in creased by approximately 50% immediately after bypass grafting and increase d by another 85% during the first 24 hours postoperatively. Endothelin leve ls were highest in patients with prolonged ventilatory requirements and ext ended stays in the intensive care unit (10.2 +/- 0.8 vs 13.2 +/- 1. 1 fmol/ mL, P =.02, and 9.8 +/- 0.7 vs 13.9 +/- 1.2 fmol/mL, P =.0 1, respectively. Endothelin sensitivity of the internal thoracic artery was increased in pa tients requiring prolonged vasodilator support with nitroglycerin. Conclusions: Systemic and pulmonary arterial endothelin levels remained inc reased for at least 24 hours postoperatively. Prolonged pharmacologic manag ement and increased intensive care unit stay were associated with increased systemic endothelin release and heightened graft-conduit sensitivity to en dothelin.