Blood endothelin-1 levels before and after carotid endoarterectomy for atherosclerotic stenosis

BACKGROUND: Elevated plasma levels of endothelin-1 (ET-1) have been reported in advanced atherosclerosis. Further in vivo demonstration of cause-effect relationship between atherosclerotic lesion and high levels of ET-1 needs to be carried out. The aim of this study was to determine whether circulating levels of ET-1 are influenced by removing haemodynamically significant atherosclerotic stenosis in selected patients with mono or bilateral carotid atherosclerotic stenosis. METHODS: Cubital venous ET-1-immunoreactive (IR) levels were measured in 20 patients: 11 (mean age+/-S.D. 63.1+/-5.36 years; range 53-70 years) were affected by monolateral, and nine patients (mean age+/-S.D. 64.7+/-9.8 years; range 52-78 years) by bilateral extracranial carotid artery atherosclerotic stenosis. ET-1-IR levels were evaluated before and 7 days after monolateral surgical endoarterectomy. Pre-surgery levels of ET-1-IR were compared with those obtained from 18 healthy younger volunteers (mean age+/-S.D. 27.8+/-2.7 years; range 20-50 years). FINDINGS: The mean cubital venous levels of ET-1-IR in the atherosclerotic patients before endoarterectomy (mean+/-S.D. 4.50+/-3.35 pg/ml; range 1.28-10.66 pg/ml) were significantly higher than those observed in healthy subjects (mean+/-S.D. 0.641+/-0.137 pg/ml; range 0.36-1.02 pg/ml) (P=0.000). The mean ET-1-IR level decreased significantly after endoarterectomy in the group of patients with monolateral stenosis (pre-surgery: mean+/-S.D. 4.35+/-3.11 pg/ml; range 1.28-10.66 pg/ml; post-surgery: mean+/-S.D. 3.05+/-2.94 pg/ml, range 0.28-8.86 pg/ml) (P=0.005), but not in patients with bilateral extracranial carotid stenosis submitted to monolateral endoarterectomy (pre-surgery: mean+/-S.D. 4.77+/-3.79 pg/ml; range 2.18-10.3 pg/ml; post-surgery: mean+/-S.D. 4.60+/-3.70 pg/ml; range 2.20-11.10 pg/ml). INTERPRETATION: The removal of a haemodynamically significant atherosclerotic vascular stenosis is associated with a decrease in the circulating ET-1-IR levels 7 days after surgery when haemodynamically significant atherosclerotic lesions are absent.