We appreciate the interest of Drs. Kempen, Basler and Daniel, Leslie, and Devereaux in our Editorial View published in the January issue of Anesthesiology.
β-blockers have shown to reduce morbidity and mortality in nonsurgical patients with coronary artery disease, including myocardial ischemia and reduced left ventricular function.1–3Thirty percent of patients undergoing noncardiac surgery each year in the United States are at risk for or are known to have coronary artery disease.4In two randomized controlled trials β-blockers have been shown to reduce perioperative mortality.5,6Oddly enough, β-blocker prescription in the perioperative setting is considered as a different indication.
Dr. Kempen is concerned about the issue of why primary care physicians should not be routinely prescribing β-blockers to high-risk patients. He is also concerned that anesthesiologists be considered to be “enabling” inferior care by assuming responsibility to initiate perioperative β-blocker therapy at a less opportune time of induction. We would be delighted if primary care physicians would prescribe β-blockers, but as reported by Nass et al., 7only 30% of patients with a history of coronary artery disease or those at risk referred to high-risk surgery are prescribed β-blockers. From our own experience (written communication, Don Poldermans, M.D. Ph.D., Professor, Department of Anesthesiology, Erasmus MC, Rotterdam, the Netherlands; April, 2004), only 25% of patients referred to high-risk surgery are chronic β-blocker users. The ability to initiate β-blocker use for a defined period before surgery represents the ideal situation, but often patients will present shortly before surgery without receiving β-blocker therapy. Realizing this important concern, Fleisher et al. 8conducted a cost-effectiveness analysis of different perioperative β-blocker strategies in high-risk patients. Their findings reveal that perioperative β-blocker use is both cost effective and efficacious from a short-term provider perspective. Furthermore, the results showed that if a β-blocker has not been started before the day of surgery, then the use of a short-acting intravenous or longer-acting oral medication would be cost-effective in high-risk surgery. Given these findings we feel that anesthesiologists could be enablers of appropriate care by initiating perioperative β-blocker use in high-risk patients.
Drs. Basler and Daniel touch on issues related to efficacy and effectiveness of perioperative β-blocker use. In this context, they feel that the Editorial View failed to identify the lack of effectiveness studies as a stumbling block to the introduction of perioperative β-blocker use into clinical practice. They are also urging for larger-scale trials to be able to state clearly which patients will benefit for perioperative β-blocker use. We acknowledge that large-scale clinical trials should provide the ultimate solution to the issue of perioperative β-blocker use in patients of different risk categories, but we disagree that lack of effectiveness studies prevent integrating evidence into clinical practice. In that respect we would like to refer to the studies of Boersma et al. 9and Fleisher et al. 8showing effectiveness and cost-effectiveness of perioperative β-blocker use in patients with known coronary artery disease or those at risk undergoing high-risk surgery. In our opinion refraining of perioperative β-blocker use in high-risk patients just because there are no larger-scale studies would potentially subject these patients to the same level of risk of perioperative cardiac complications as before the introduction of perioperative β-blocker use.
Finally, Drs. Leslie and Devereaux would like to see more definitive evidence from large-scale randomized clinical trials before embarking on strong recommendations. They fear that current evidence is limited and does not justify routine use of perioperative β-blocker use. To overcome these concerns they propose to wait until their own trial would provide more solid evidence about the effectiveness of perioperative β-blocker use. We agree that information with regard to the protective effect of perioperative β-blocker use in patients with moderate risk for cardiac complications is limited. However, we feel that there is scientific evidence that perioperative β-blocker use in high-risk patients proved to be effective for the reduction of perioperative cardiac complications.5,9Given these findings the practice guidelines of the American College of Cardiology/American Heart Association and the American College of Physicians recommend perioperative β-blocker therapy with one or more risk factors correlated with higher risk of cardiac complications.
In summary, perioperative β-blocker use should be considered inherent to the patient at risk and not the type of surgical procedure to be performed. Evidence from the available studies can already be used to plan an effective approach for perioperative β-blocker use in high-risk patients while ongoing clinical trials will provide further evidence for recommendations using β-blockers in patients at low-to-intermediate risk for perioperative cardiac complications.
* Erasmus Medical Center, Rotterdam, The Netherlands. email@example.com