Published in the February 2007 issue of Today’s Hospitalist.
While several recent, well-publicized studies have called into question the benefit of using a beta-blocker to minimize the risk of cardiac complications during and after non-cardiac surgery, experts say that the drug still offers essential protection for many patients. And they say that hospitalists can play an important role in getting that protection to perioperative patients.
In fact, many perioperative medicine experts would argue that the real problem surrounding beta-blockers is not one of over-prescribing, but one of underuse. Studies find that many surgical patients who could benefit from beta-adrenergic blocking agents aren’t getting them at the right time and in the right dose.
Even at large hospitals that focus on appropriate beta-blockade, for instance, as many as two-thirds of patients who could benefit don’t receive perioperative beta-blockers. According to one study of a single hospital, as many as 90 lives may be lost there every year because appropriate beta-blockade isn’t being delivered.
Hospitalists are the go-to physicians to ensure that care takes place, according to Andrew D. Auerbach, MD, MPH, associate professor of medicine at the University of California, San Francisco (UCSF). That’s because hospitalists are not only increasingly co-managing surgical patients, but they are the physicians most attuned to the problems that can occur when multiple physicians from different services are involved in a patient’s care.
For surgical patients at elevated risk for cardiac events, "There is a cascade of care they go through, from home to a preop clinic to the operating room and recovery," Dr. Auerbach told an audience of hospitalists at the Fall 2006 Hospitalist CME Series meeting in Tampa, Fla. "That gives you a lot of places to drop the ball."
While perioperative beta-blockade "is hard to do," Dr. Auerbach urged hospitalists to take the lead in devising strategies to predict and prevent cardiac complications of surgery. Because hospitalists know the hospital system, he pointed out, they are the ones who can figure out how to work around the weak links where optimal care can fall through the cracks.
He suggested hospitalists ask themselves the following questions: How do people get to your OR? How are discharge meds coordinated, and who is going to pay attention to patients after they leave the OR? Based on the answers to these questions, he added, hospitalists need to devise a perioperative strategy that is "so simple, people can’t refuse."
Target high-risk patients
Part of providing effective perioperative care includes knowing how to get around barriers to appropriate care. According to Dr. Auerbach, coordinating surgeons, anesthesiologists, hospitalists, housestaff and attendings is only the start.
Other obstacles to proper perioperative beta-blockade include what he described as the "shouldn’t someone else do it?" phenomenon, the "I don’t believe the data" barrier, particularly for low-risk patients, and the problem of varying order sets and algorithms.
Nonetheless, Dr. Auerbach recommends that hospitalist strategies focus on getting perioperative beta-blockade for the "highest-risk patients"-and making sure they get it as early as possible "before the patient goes to the OR."
"That’s where we feel that the data are best and where you’ll get the most benefit," he said. "Giving ourselves as much time as possible before patients go to the OR is key."
A new preoperative approach
The most recent batch of studies show that less sick patients-those who score one point or less on the revised cardiac risk index (RCRI), unless that one point is coronary artery disease (CAD)-probably should not receive perioperative beta-blockers, he said, particularly for non-vascular surgery. The risks of complications probably exceed the benefits.
This is particularly true if the one point is due to diabetes. Research published in the June 24, 2006, British Medical Journal on the effect of perioperative beta-blockade looked at patients with diabetes undergoing major non-cardiac surgery. Like several other studies before it, Dr. Auerbach said, this one found that "perioperative metoprolol did not significantly affect mortality and cardiac morbidity in patients with diabetes," all of whom were beta-blocker naive.
In addition, the patients who received beta-blockers during the study, which was called the Diabetes Postoperative Mortality and Morbidity (DIPOM) trial, experienced more bradycardia and hypotension needing treatment than those on placebo.
While large randomized controlled trials of perioperative beta-blockade are currently underway, Dr. Auerbach said the latest thinking urges clinicians to "raise the bar for starting beta-blockers." Patients should receive beta-blockers, he said, only if they have a history of coronary artery disease or if they have two or more of the criteria listed in the RCRI. (See "Assessing perioperative risk: the revised cardiac risk index," left.)
This strategy should be part of a new way of looking at the role of preoperative evaluation. The idea, he said, isn’t necessarily to "tune up" someone before surgery, but instead "to screen patients for unstable symptoms who would require an intervention or beta-blockers anyway."
"There is no preventive revascularization anymore," he pointed out. "Think about preoperative evaluation as a chance to perform primary prevention only for the highest-risk patients." For all others, he added, it is an opportunity for secondary prevention. "You’re starting beta-blockers and statins in those who need them anyway."
So what should hospitalists do to prevent cardiac complications of surgery? First, Dr. Auerbach said, watch out for the most worrisome symptoms, the ones that really raise the risks that can be lowered by beta-blockers and potentially other drugs, including clonidine and statins. Red-flag symptoms indicate new or unstable coronary artery disease, heart failure, or aortic stenosis, which is often overlooked.
"Do a careful physical exam, listen for the murmur, feel the pulses and make sure that patients aren’t going to the OR with unrecognized aortic stenosis," he said. "That’s a risk at least as high, if not higher, than the highest risk category of coronary disease."
Pay particular attention, he said, to new symptoms related to chest pain or shortness of breath. You also need to order electrocardiograms for patients who have multiple risk factors for coronary or a history of coronary disease "to make sure they haven’t had a new MI since their last one."
The next question you need to ask is whether the planned surgery is an emergency. If it isn’t, Dr. Auerbach recommended that hospitalists try to have the operation delayed for suspect patients just long enough to permit a better evaluation of risks and to allow preventive agents to be started early enough.
What studies have shown, he said, is that "people who were not adequately beta-blocked before surgery didn’t do nearly as well" as those given a chance to let the beta-blockers work.
"IV beta-blockers in the preop holding area are likely to have an effect," he pointed out, "but it probably isn’t the best."
After negotiating timing with the patient, surgeon and any other physicians involved, Dr. Auerbach suggested that hospitalists use the RCRI criteria to determine who needs beta-blockade.
Targeting higher-risk patients
While "the ‘give them all beta-blockers and don’t worry’ approach may not be the best one to take," said Dr. Auerbach, studies show that patients with a RCRI score of two or higher continue to benefit from beta-blockers.
If their score is two, he pointed out, the next question to ask is, "Are you able to walk two flights of stairs?" or "Do you have a history of chest pains or claudication when you’ve exerted yourself in the past?"
As Dr. Auerbach detailed in an algorithm for assessing and reducing cardiac risk in non-cardiac surgery that was published in the March 2006 Circulation, these patients may need a noninvasive stress test. (He also recommended that all patients with three or more major RCRI criteria, "unless they ran a marathon last week," should likewise get non-invasive stress testing.) Test results in turn can help you decide if patients need beta-blockers plus statins (only if there is long-term need) before surgery, or if patients need further testing.
"The goal here is to find a patient who requires revascularization in the absence of a surgery," he said.
Patients who should receive beta-blockers include those with a history of coronary artery disease; angioplasty; coronary artery bypass graft; use of nitrates for chest pain; TIA or cerebrovascular disease; a creatinine greater than two; patients with poorly controlled type 2 diabetes; and anyone getting open chest, abdomen or pelvis vascular surgery.
Dr. Auerbach does not, however, recommend starting a patient with heart failure on beta-blockers just before vascular surgery, "unless the patient is on them already."
The latest word on statins, clonidine
In terms of statins, observational but compelling evidence is emerging that patients who get statins around the time of surgery have a lower risk of death in the hospital and afterwards.
"At this point, the evidence for statins is not strong enough for us to support using them outside of patients who are on them already," said Dr. Auerbach, adding that he wouldn’t start patients on statins just for surgery. He pointed out, however, that many patients with heart disease ought to be on statin therapy. "A preoperative workup sometimes can be the trigger to get proper care, such as this, started."
Clonidine is another drug used perioperatively. Although there have been no head-to-head comparisons with beta-blockers, you may have patients whom you feel uncomfortable giving IV metoprolol to, but need something.
For these people, a clonidine patch can be an option. At UCSF, however, the hospitalists tend to "avoid clonidine the best we can," said Dr. Auerbach, in part because it is not available outside the hospital and because of withdrawal concerns.
"If you worry about beta-blocker withdrawal," he said, "you should be terrified about clonidine withdrawal."
For high-risk patients, evidence shows that beta-blocker doses should be increased perioperatively. Higher beta-blocker doses are associated with lower long-term mortality after vascular surgery. And dosages should be titrated until a patient’s heart rate is 55-65 beats per minute.
Another key consideration to include in your perioperative strategy: making sure beta-blockers aren’t stopped too soon.
"Be very careful that beta-blockers aren’t stopped when patients leave the hospital," said Dr. Auerbach. "You have an eight-day rule, and that’s another potential harm."
Deborah Gesensway is a freelance writer who reports on U.S. health care from Toronto, Canada.
A perioperative beta-blocker protocol
At the Fall 2006 Hospitalist CME Series meeting in Tampa, Fla., Andrew D. Auerbach, MD, MPH, associate professor of medicine at the University of California, San Francisco (UCSF), spelled out elements of UCSF’s perioperative beta-blocker protocol. Those elements include:
- Screening in preoperative clinics, which see more than 95% of patients scheduled for elective surgery.
- Using eligibility criteria based on an algorithm published in the March 2006 Circulation, with PO metoprolol started that day or pre-existing beta-blocker dose titrated.
- Titrating postoperative beta-blocker dose based on heart rate.
- Giving IV metoprolol off telemetry in NPO patients. Encouraging more medications by NG, fewer strict NPO patients.
- Ordering carry-through medications at discharge, with beta-blockers continued for seven days or until discharge, whichever is longer, and indefinitely in patients with long-term indication.