Continued cigarette smoking after coronary artery bypass surgery reduces endothelium-dependent vasodilation in internal thoracic artery grafts.
BACKGROUND
Cigarette smoking is known to promote endothelial dysfunction, thus it can be responsible for an impaired endothelium-dependent vasomotility in arterial grafts late after coronary surgery.


METHODS
Twenty consecutive patients (mean age 64.5 years), previously submitted to coronary bypass surgery with the internal thoracic artery, underwent quantitative angiography of the implanted graft at long-term follow-up (mean time 2.5 years). To assess both endothelium-dependent and independent vasomotility, angiograms were acquired before and after selective infusions of acetylcholine (10(-6) mmol/ml) and nitroglycerine (500 microg). The predictive value of risk factors, including previous and continued smoking, for an impairment in endothelium-dependent vasomotility was assessed.


RESULTS
Continued smoking (p = 0.038), but not a previous history of smoking (p = 0.55) was the only predictor of a reduced endothelium-dependent vasodilation. While previous smokers and non-smokers showed a similar response to acetylcholine, current smokers showed a reduced endothelium-dependent vasodilation vs non-smokers (94.8 +/- 2.6 vs 99.6 +/- 2.3% of the maximal vasodilative capacity, p = 0.001).


CONCLUSIONS
Although maintained, the vasodilative response to acetylcholine appears reduced in internal thoracic artery grafts of patients who continued smoking long term after coronary bypass surgery. Whether this could affect the long-term outcome of these patients has to be further investigated.
Amoroso
G
G
Department of Cardiology, Thoraxcenter, University Hospital Groningen, The Netherlands. G.Amoroso@thorax.azg.nl
Mariani
M A
MA
Tio
R A
RA
Grandjean
J G
JG
D000109:Acetylcholine / Q000494:pharmacology; D000368:Aged; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000503:physiopathology* / Q000601:surgery; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D012907:Smoking / Q000009:adverse effects*; D013895:Thoracic Arteries / Q000502:physiology* / Q000637:transplantation*; D014664:Vasodilation / Q000187:drug effects
D000109:Acetylcholine