Can metoprolol (beta-blocker) be restarted after Coronary Artery Bypass Grafting (CABG)?

From the Guidelines

Yes, metoprolol (beta-blocker) can be restarted after Coronary Artery Bypass Grafting (CABG).

Rationale for Restarting Beta-Blockers

• Beta-blockers, such as metoprolol, should be reinstituted as soon as possible after CABG in all patients without contraindications to reduce the incidence or clinical sequelae of postoperative atrial fibrillation (AF) 1.
• The American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guidelines recommend the use of beta-blockers before and after CABG to reduce the risk of postoperative AF and its complications 1.
• Although recent studies have shown that beta-blocker use may not impact cardiovascular morbidity and mortality rates, they may still reduce the incidence of AF and ventricular arrhythmias, as well as hospital stay 1.

Important Considerations

• The decision to restart beta-blockers after CABG should be individualized and based on the patient's clinical presentation and contraindications 1.
• Patients with known coronary artery disease (CAD) who are scheduled for high-risk vascular surgery, including CABG, should receive beta-blockers and statins prior to and continued post-operatively 1.

From the FDA Drug Label

Chronically administered beta-blocking therapy should not be routinely withdrawn prior to major surgery; however, the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical procedures

• The FDA drug label does not directly address the question of restarting metoprolol after Coronary Artery Bypass Grafting (CABG).
• However, it does mention that chronically administered beta-blocking therapy should not be routinely withdrawn prior to major surgery 2.
• It can be inferred that metoprolol can likely be restarted after CABG, but the decision to do so should be made on a case-by-case basis, considering the individual patient's condition and medical history.
• Caution should be exercised when restarting metoprolol, and the patient should be carefully monitored for any signs of heart failure or ischemic heart disease.

From the Research

Restarting Metoprolol after CABG

• The decision to restart metoprolol after Coronary Artery Bypass Grafting (CABG) depends on various factors, including the patient's overall health, left ventricular function, and the presence of any contraindications to beta-blocker therapy 3, 4.
• Studies have shown that metoprolol can be effective in preventing atrial fibrillation and flutter in the postoperative period of CABG surgery, with a significant reduction in the incidence of supraventricular arrhythmias 3, 4.
• However, the efficacy of metoprolol in preventing atrial fibrillation after CABG may be influenced by factors such as age, left ventricular ejection fraction, and the presence of underlying heart disease 5, 6.
• A study comparing the efficacy of metoprolol and carvedilol for preventing atrial fibrillation after CABG found that carvedilol was superior to metoprolol in decreasing the development of early postoperative atrial fibrillation 6.
• Another study found that long-term treatment with metoprolol after CABG did not reduce death or the development of cardiac events, but the 95% confidence limits ranged from a 30% reduction in events to a 68% increase in events if patients were treated with metoprolol as compared with placebo 7.

Key Considerations

• The patient's left ventricular function and overall health should be carefully evaluated before restarting metoprolol after CABG 5, 7.
• The presence of any contraindications to beta-blocker therapy, such as bronchospasm or heart block, should be carefully considered before restarting metoprolol 3, 4.
• The dosage and duration of metoprolol therapy should be individualized based on the patient's response and tolerance to the medication 4, 6.