Perioperative ß-Blocker Therapy? Some Real Answers
Many of my colleagues prescribe ß-blocker therapy for patients who are about to undergo surgery. Is routine perioperative use of these agents appropriate? Each year, about 27 million Americans undergo anesthesia followed by surgery.1 Roughly 50,000 of these patients have a stress-induced myocardial infarction during the perioperative period. The National Quality Forum2 has suggested that ß -blocker therapy would decrease coronary events in an at-risk population. Some studies, however, have challenged the claims of perioperative -blocker efficacy.3,4 The question remains hotly debated: Who should receive these agents—and when? Newly published information sheds light on this debate.5 Lindenauer and colleagues looked at in-hospital mortality in a retrospective cohort study of over 122,000 patients 18 years or older who received perioperative -blocker therapy before noncardiac surgery. To quantify each patient’s risk of coronary complications, a so-called Revised Cardiac Risk Index (RCRI) score was used. This index ascribes points to each of the following risk factors: • High-risk surgery (intrathoracic, intraperitoneal, or vascular procedures above the inguinal ligament): 1 point. • Known ischemic heart disease, cerebrovascular disease, renal insufficiency (creatinine level greater than 2 mg/dL): 3 possible points. • Diabetes mellitus: 1 point. Patients who scored 0 or 1 point either did not benefit from ß blockade or were actually harmed. However, those with 2 or more points had a relative risk of coronary death ranging from 58% to 88% of that of patients with the same RCRI score who did not receive ß -blocker therapy. Those who scored 3 or more points benefited the most. For example, in patients with an RCRI score of 4 or more who received ß -blocker therapy, the relative risk of cardiac death was 58% of that of patients with the same score who did not receive such therapy. What do these findings mean for your practice? Perioperative administration of a ß -blocker may benefit your patients who are scheduled for highrisk surgery (1 point) and who score at least 2 more points on the RCRI scale. Those with an RCRI score of less than 3 points should not receive such therapy until more evidence accumulates.6 REFERENCES: 1. Fleisher LA, Eagle KA. Clinical Practice. Lowering cardiac risk in noncardiac surgery. N Engl J Med. 2001;345:1677-1682. 2. National Quality Forum. Safe Practices for Better Healthcare: A Consensus Report. Washington, DC; 2003. Publication NQFCR-05-03. 3. Yang H, Raymer K, Butler R, Parlow J. Metoprolol after vascular surgery (MaVS). Can J Anesth. 2004;51:A7. 4. Juul AB. Randomized, blinded trial on perioperative metoprolol versus placebo for diabetic patients undergoing noncardiac surgery. Presented at: American Heart Association 2004 Annual Scientific Sessions; November 7-10, 2004; New Orleans. 5. Lindenauer PK, Pekow P, Wang K, et al. Perioperative beta-blocker therapy and mortality after major noncardiac surgery. N Engl J Med. 2005;353:349-361. 6. Poldermans D, Boersma E. Beta-blocker therapy in noncardiac surgery. N Engl J Med. 2005;353:412-414.