Better preserved pulmonary endothelium-dependent vasodilation with off-pump coronary surgery.
OBJECTIVE
To investigate if endothelium-dependent vasodilation in the pulmonary circulation was better maintained after off-pump coronary artery bypass grafting (CABG). An impaired pulmonary vascular response to acetylcholine has been observed after cardiopulmonary bypass (CPB) in children, adults and experimentally.


METHODS
Fourteen patients operated off-pump were compared with 21 patients undergoing conventional CABG with CPB. The indexed pulmonary vascular resistance was measured before and during an infusion of acetylcholine, aiming at a concentration of 10(-6) mol/l in the pulmonary artery. Twelve patients operated on-pump received saline instead of acetylcholine.


RESULTS
Before surgery pulmonary vascular resistance decreased during infusion of acetylcholine by 28% and 25% in the off-pump and on-pump groups. After surgery the decrease was 16% and 6%, respectively (p = 0.028 and p < 0.001, compared to preoperative response). The response did not differ between the two groups before, but did so after surgery (p = 0.01). Saline had no effect.


CONCLUSIONS
The better maintained endothelium-dependent vasodilation in the off-pump group indicated less endothelial dysfunction.
Angdin
M
M
Department of Surgical Sciences, Karolinska Institute, Stockholm, Sweden. 087527848@telia.com
Settergren
G
G
Vaage
J
J
D000109:Acetylcholine / Q000494:pharmacology; D000368:Aged; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass / Q000379:methods*; D017558:Elective Surgical Procedures; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008168:Lung / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D011652:Pulmonary Circulation / Q000187:drug effects / Q000502:physiology*; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D000109:Acetylcholine