Esmolol cardioplegia in unstable coronary revascularisation patients. A randomised clinical trial

BACKGROUND: Esmolol has been studied and applied to control hypertension and tachycardia during open heart surgery. Esmolol has been used on a minor scale as a single cardioplegic agent. Little information is available on esmolol as a component of blood cardioplegia. In this prospective, randomised, double-blind clinical study we investigated whether esmolol improves cardioprotection in patients scheduled for an urgent coronary operation. METHODS: Forty patients with unstable angina were operated using cold blood cardioplegia as the basic cardioprotective method. Cardioplegia was infused intermittently, and esmolol was given into the cardioplegia line (15 mg/min) during cold infusions. Patients with ongoing myocardial infarction were excluded. RESULTS: The arrest time during the cardioplegic induction or the rate of spontaneous resumption of the heart rhythm did not differ significantly between the groups. The serial measurements of plasma creatine kinase MB-fraction activity (P=0.27), serum creatine kinase MB-fraction mass assay (P=0.16), troponin I (P=0.41) and myoglobin (P=0.14) similarly did not differ between the groups, nor did myocardial lactate extraction (P= 0.12). CONCLUSION: Esmolol addition to blood cardioplegia did not increase the efficacy of cardioprotection in the present study setting in unstable patients during urgent coronary revascularisation.