Whither perioperative beta blockade?

What are we to do now that much of the literature on this topic is beset with allegations of research fraud? A review last year in the green journal tried to make sense of things. Key points:

• The evidence regarding the cardiac benefit of perioperative beta blockade is in doubt owing to allegations of research fraud.

• Perioperative beta blockade must be administered appropriately and judiciously in a narrow spectrum of patients.

• Whenever implemented, attention to hemodynamic parameters is critical to ensure the safety of perioperative beta blockade.

• Greater oversight and structural reform is necessary to prevent perioperative research misconduct.

The authors go through the rapidly swinging pendulum of the last few years concerning perioperative beta blockers and elaborate on the above points:

1 First, we must exercise clinical restraint and recognize the double-edged sword that is perioperative beta-blocker treatment. While beta-blockers blunt surgical hemodynamic stress to preserve myocardial oxygen supply, the price paid is failure to augment cardiac output in situations where blood loss, systemic vasodilation, and intravascular volume shifts are the norm. This scenario is more compelling in the elderly, who, owing to preexisting vascular stiffness and reductions in peak heart rates, have narrower volume “set-points” and are more at risk of systemic collapse. We must therefore limit beta blockade to patients with established coronary artery disease already on this therapy, or in those with documented ischemia and concerning cardiac symptoms facing high-risk surgery. Any generalizations beyond these subsets are not supported by current evidence and may be associated with significant harm.

2 Second, in a post-POISE era, we can no longer afford to overlook the risks associated with this treatment. Whenever considered, beta-blockade should be started weeks, not days, before surgery with slow and careful titration to individual heart rate and blood pressure. Correspondingly, unless concerns about hemodynamic instability surface, beta-blockers must not be discontinued abruptly in patients undergoing surgery in order to avoid precipitating a withdrawal state leading to sympathetic activation and cardiac events. However, even when administered for appropriate indications, careful monitoring for hypotension and bradycardia coupled with judicious withholding of medication must be planned. Without such supervision, perioperative beta blockade remains a dangerous and potentially lethal practice.