There has been a great deal of interest in the utility of peri-operative beta blockade for high-risk non-cardiac surgical patients as a means of reducing peri-operative cardiac morbidity. Of the approximately 30 million surgeries performed annually, one million patients have known coronary artery disease, and an additional two to three million are at risk for coronary artery disease. These patients have higher rates of peri-operative myocardial infarction (MI), cardiac death, and other non-fatal outcomes related to ischemic heart disease. In a recent claims analysis, the charges associated with a peri-operative MI amounted to US$15,000, and the cost of cardiac death was US$21,909.Therefore, there are significant economic reasons, in addition to the health-related rationale, to define strategies and develop interventions that reduce peri-operative cardiac morbidity. 1
The utility of beta blockers in the peri-operative period has been of interest to clinicians and investigators for almost three decades. Numerous studies have been performed in the non-operative setting that demonstrate the value of beta blockade in patients with known or risk factors for cardiac disease, as well as the implications of the under-use of this treatment modality. Among the first studies in the peri-operative literature were those demonstrating that withdrawal of beta blockade is associated with tachycardia and an increased incidence of myocardial ischemia. 2 It is therefore undisputed that patients previously on beta-blockers should remain on these agents. This has been classified as a level I recommendation by the American Heart Association/American College of Cardiology (AHA/ACC) Guidelines for Peri-operative Cardiovascular Evaluation for Noncardiac Surgery. 3 The controversy has developed with respect to the utility, timing, and protocol for initiation of beta blockade in patients who were not previously taking these agents.
Mangano and colleagues published the first randomized controlled trial (RCT) in a cohort of 200 patients with known or risk factors for coronary artery disease undergoing high-risk non-cardiac surgery. 4 They administered atenolol or placebo beginning the morning of surgery and continuing for seven days post-operatively, and demonstrated a marked reduction in the incidence of peri-operative myocardial ischemia, although there were no differences in the rates of peri-operative cardiac morbidity. It is important to note that there was a marked improvement in survival at six months in the atenolol group, which continued for at least two years. The authors speculated that the lower incidence of myocardial ischemia may have resulted in less plaque destabilization, in turn resulting in improved sixmonth survival, although there were issues of randomization, uneven distribution of risk factors, and treatment at baseline and upon discharge with betablockers that could, in part, account for the findings.
- Fleisher L A, Corbett W, Berry C and Poldermans D, ├óÔé¼┼øCost-effectiveness of differing perioperative beta-blockade strategies in vascular surgery patients├óÔé¼┼Ñ, J. Cardiothorac.Vasc. Anesth. (2004), 18: pp. 7├óÔé¼ÔÇ£13.
- Prys-Roberts C, Meloche R and Foex P, ├óÔé¼┼øStudies of anaesthesia in relation to hypertension: I. cardiovascular responses to treated and untreated patients├óÔé¼┼Ñ, Br. J. Anesth. (1971), 43: pp. 122├óÔé¼ÔÇ£137.
- Eagle K A, Berger P B, Calkins H et al.,├óÔé¼┼øACC/AHA guideline update for perioperative cardiovascular evaluation for noncardiac surgery ├óÔé¼ÔÇ£ executive summary a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines├óÔé¼┼Ñ, (Committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery), Circulation (2002), 105: pp. 1,257├óÔé¼ÔÇ£1,267.
- Mangano D T, Layug E L,Wallace A and Tateo I, ├óÔé¼┼øEffect of atenolol on mortality and cardiovascular morbidity after noncardiac surgery. Multicenter Study of Perioperative Ischemia Research Group├óÔé¼┼Ñ, N. Engl. J. Med. (1996), 335: pp. 1,713├óÔé¼ÔÇ£1,720.
- Poldermans D, Boersma E, Bax J J et al., ├óÔé¼┼øThe effect of bisoprolol on perioperative mortality and myocardial infarction in highrisk patients undergoing vascular surgery├óÔé¼┼Ñ, Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography Study Group [see comments], N. Engl. J. Med. (1999), 341: pp. 1,789├óÔé¼ÔÇ£1,794.
- Boersma E, Poldermans D, Bax J J et al., ├óÔé¼┼øPredictors of cardiac events after major vascular surgery: Role of clinical characteristics, dobutamine echocardiography, and beta-blocker therapy├óÔé¼┼Ñ, JAMA (2001), 285: pp. 1,865├óÔé¼ÔÇ£1,873.
- Urban M K, Markowitz S M, Gordon M A et al.,├óÔé¼┼øPostoperative prophylactic administration of beta-adrenergic blockers in patients at risk for myocardial ischemia├óÔé¼┼Ñ, Anesth. Analg. (2000), 90: pp. 1,257├óÔé¼ÔÇ£1,261.
- Zaugg M,Tagliente T, Lucchinetti E et al.,├óÔé¼┼øBeneficial effects from beta-adrenergic blockade in elderly patients undergoing noncardiac surgery├óÔé¼┼Ñ, Anesthesiology (1999), 91: pp. 1,674├óÔé¼ÔÇ£1,686.
- Shojania K G, Duncan B W, McDonald K M and Wachter R M,├óÔé¼┼øSafe but sound: patient safety meets evidence-based medicine├óÔé¼┼Ñ, JAMA (2002), 288: pp. 508├óÔé¼ÔÇ£513.
- Auerbach A D and Goldman L, ├óÔé¼┼øbeta-Blockers and reduction of cardiac events in noncardiac surgery: scientific review├óÔé¼┼Ñ, JAMA (2002), 287: pp. 1,435├óÔé¼ÔÇ£1,444.
- Yang H, Raymer K, Butler R et al., ├óÔé¼┼øMetoprolol after vascular surgery (MaVS)├óÔé¼┼Ñ, Can. J. Anaesth. (2004),71: A7 (abstract).
- Giles J W, Sear J W and Foex P, ├óÔé¼┼øEffect of chronic beta-blockade on peri-operative outcome in patients undergoing non-cardiac surgery: an analysis of observational and case control studies├óÔé¼┼Ñ, Anaesthesia (2004), 59: pp. 574├óÔé¼ÔÇ£583.
- Raby K E, Brull S J, Timimi F et al., ├óÔé¼┼øThe effect of heart rate control on myocardial ischemia among high-risk patients after vascular surgery├óÔé¼┼Ñ, Anesth. Analg. (1999), 88: pp. 477├óÔé¼ÔÇ£482.
- Stevens R D, Burri H and Tramer M R, ├óÔé¼┼øPharmacologic myocardial protection in patients undergoing noncardiac surgery: a quantitative systematic review├óÔé¼┼Ñ, Anesth. Analg. (2003), 97: pp. 623├óÔé¼ÔÇ£633.
- Poldermans D, Bax J J, Kertai M D et al., ├óÔé¼┼øStatins are associated with a reduced incidence of perioperative mortality in patients undergoing major noncardiac vascular surgery├óÔé¼┼Ñ, Circulation (2003), 107: pp. 1,848├óÔé¼ÔÇ£1,851.
- Wallace A W, Galindez D, Salahieh A et al., ├óÔé¼┼øEffect of clonidine on cardiovascular morbidity and mortality after noncardiac surgery├óÔé¼┼Ñ, Anesthesiology (2004), 101: pp. 284├óÔé¼ÔÇ£293.
- Durazzo A E, Machado F S, Ikeoka D T et al., ├óÔé¼┼øReduction in cardiovascular events after vascular surgery with atorvastatin: a randomized trial├óÔé¼┼Ñ, J.Vasc. Surg. (2004), 39: pp. 967├óÔé¼ÔÇ£975, discussion pp. 75├óÔé¼ÔÇ£76