Randomised comparison of the effects of nicardipine and esmolol on coronary artery wall stress: implications for the risk of plaque rupture.
OBJECTIVE
To determine whether the beta blocker esmolol reduces coronary artery wall stress more than the short acting dihydropyridine calcium antagonist nicardipine.


METHODS
Randomised double blind placebo controlled trial.


METHODS
Tertiary cardiology centre.


METHODS
Patients with coronary artery disease.


METHODS
20 patients were randomised double blind to an infusion of nicardipine (n = 10) or esmolol (n = 10) titrated to reduce systolic blood pressure by 20 mm Hg.


METHODS
Peak systolic wall circumferential stress.


RESULTS
Esmolol reduced peak coronary stress by a mean of 0.17 x 10(6) dyn/cm(2) (95% confidence interval (CI) 0.14 to 0.21 x 10(6) dyn/cm(2)) compared with a reduction of 0.07 x 10(6) dyn/cm(2) (95% CI 0.05 to 0.10 x 10(6) dyn/cm(2)) after nicardipine. Peak systolic radius was reduced by 0.04 mm (95% CI 0.03 to 0.06 mm) after esmolol compared with an increase of 0.08 mm (95% CI 0.05 to 0.10 mm) after nicardipine. Heart rate increased by 11.5 beats/min (95% CI 6.9 to 16.2 beats/min) after nicardipine and decreased by 5.3 beats/min (95% CI 1.9 to 8.6 beats/min) after esmolol.


CONCLUSIONS
Intravenous esmolol is more effective than nicardipine at reducing circumferential coronary artery wall stress.
Williams
M J
MJ
Department of Medicine, University of Otago, 201 Great King Street, Dunedin, New Zealand. michael.williams@stonebow.otago.ac.nz
Low
C J
CJ
Wilkins
G T
GT
Stewart
R A
RA
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000188:drug therapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009529:Nicardipine / Q000627:therapeutic use*; D011412:Propanolamines / Q000627:therapeutic use*; D013314:Stress, Mechanical; D018084:Ultrasonography, Interventional
D000319:Adrenergic beta-Antagonists; D002121:Calcium Channel Blockers; D011412:Propanolamines; D009529:Nicardipine; C036604:esmolol