A new antispastic solution for arterial grafting: nicardipine and nitroglycerin cocktail in preparation of internal thoracic and radial arteries for coronary surgery.
OBJECTIVE
Antispastic protocols for arterial grafts are important in arterial grafting for coronary artery bypass grafting surgery. We designed a new nicardipine and nitroglycerin cocktail that is composed of a second-generation dihydropyridine calcium antagonist, nicardipine and nitroglycerin (30 micromol/L), and examined its effect in human internal thoracic and radial arteries.


METHODS
Human internal thoracic (n = 86) and radial (n = 74) artery segments from 72 patients undergoing coronary artery bypass grafting were studied. Relaxation against 3 classic vasoconstrictors (potassium chloride, thromboxane A(2) mimetic U46619, and alpha-adrenoceptor agonist norepinephrine) and prophylactic effect on contraction against these vasoconstrictors were examined. The effect of the nicardipine and nitroglycerin cocktail on the endothelial function in internal thoracic and radial arteries was studied in response to acetylcholine.


RESULTS
Nicardipine and nitroglycerin induced almost full relaxation (92.2% +/- 4.7% to 97.9% +/- 1.0%, P < .001 in internal thoracic arteries and 95.4% +/- 1.9% to 96.7% +/- 3.3%, P < .001 in radial arteries, n = 6-8) against 3 vasoconstrictors with significant prophylactic effect on contraction (maximal contraction was depressed to 32.5% to 76.4%, P < .05 or P < .001, and EC50s were increased to 5 to 42-fold more, P < .01). After treatment with the nicardipine and nitroglycerin cocktail, the acetylcholine-induced relaxation was unchanged (P > .05).


CONCLUSIONS
The use of the nicardipine and nitroglycerin cocktail provides a new antispastic protocol that has rapid onset, full relaxation, and excellent prophylactic effect against all known mechanisms of vasospasm and maximally protects the endothelial and smooth muscle function of the internal thoracic and radial arteries. The cocktail is therefore expected to provide a new method in treating grafts in coronary artery bypass grafting with the best antispastic effect and protection of the graft.
He
Guo-Wei
GW
Nankai University Medical College and TEDA International Cardiovascular Hospital, Tianjin, China. gwhe@cuhk.edu.hk
Fan
Li
L
Furnary
Anthony
A
Yang
Qin
Q
D002121:Calcium Channel Blockers / Q000008:administration & dosage* / Q000494:pharmacology; D001026:Coronary Artery Bypass / Q000379:methods; D004338:Drug Combinations; D004730:Endothelium, Vascular / Q000187:drug effects; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D009529:Nicardipine / Q000008:administration & dosage* / Q000494:pharmacology; D005996:Nitroglycerin / Q000008:administration & dosage* / Q000494:pharmacology; D010276:Parasympatholytics / Q000008:administration & dosage* / Q000494:pharmacology; D017534:Radial Artery / Q000187:drug effects*; D013895:Thoracic Arteries / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D002121:Calcium Channel Blockers; D004338:Drug Combinations; D010276:Parasympatholytics; D014662:Vasoconstrictor Agents; D009529:Nicardipine; D005996:Nitroglycerin