INTRODUCTION: Perioperative myocardial ischemia occurs in 20-40% of patients at risk for cardiac morbidity and is associated with a 9-fold increase in risk of perioperative cardiac death, myocardial infarction, or unstable angina, and a 2-fold risk long-term. Perioperative atenolol administration reduces the risk of death for as long as 2 years after surgery. This randomized, placebo-controlled, double-blinded, trial tested the hypothesis that perioperative atenolol administration reduces the incidence and severity of perioperative myocardial ischemia, potentially explaining the observed reduction in the risk of death.
METHODS: Two-hundred patients with, or at risk for, coronary artery disease were randomized to two study groups (atenolol vs. placebo). Monitoring included a preoperative history and physical examination and daily assessment of adverse events. Twelve-lead electrocardiography (ECG), 3-lead Holter ECG, and creatinine phosphokinase with myocardial banding (CPK with MB) data were collected from 24 hours before and until 7 days after surgery. Atenolol (0, 5, or 10 mg) or placebo was administered intravenously before induction of anesthesia and every 12 hours postoperatively, until the patient was able to take oral medications. Atenolol (0 mg, 50 mg or 100 mg) was then administered orally once a day as specified by blood pressure and heart rate.
RESULTS: During the postoperative period there was a significant reduction in the incidence of myocardial ischemia in the atenolol group: days 0-2 (atenolol 17/99 vs. placebo 34/101, p=0.008) and days 0-7 (atenolol 24/99 vs. placebo 39/101, p=0.029). Patients with episodes of myocardial ischemia were more likely to die over the next 2 years (p=0.025).
CONCLUSIONS: Perioperative administration of atenolol for one week to patients at high risk for coronary artery disease significantly reduces the incidence of postoperative myocardial ischemia. Reductions in perioperative myocardial ischemia are associated with reductions in the risk of 2 year mortality.
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