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.
DESIGN: Randomised double blind placebo controlled trial.
SETTING: Tertiary cardiology centre. PATIENTS: Patients with coronary artery disease.
INTERVENTIONS: 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. MAIN OUTCOME MEASURES: 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.

RCT Entities:   Population Interventions Outcomes