Cochrane: As the population is ageing, more people will undergo major vascular surgery, which carries an increased risk of cardiac complications. The increased risk of cardiac complications is often the result of asymptomatic heart disease. Treating severe symptoms, such as critical limb ischaemia (severely narrowed arteries of the lower limbs resulting in rest pain, ulcers, or gangrene), in people with peripheral arterial disease is a common reason for undergoing vascular surgery, which carries an increased risk
heart attack (myocardial infarction) ranging from 5% to 24% during and
shortly after surgery.
There is clear evidence for the use of
beta-blockers (a class of medications used to treat certain heart
conditions as well as high-blood pressure and other conditions) to
reduce cardiac risk in people with known heart disease, and it has been suggested that beta-blockers may reduce short-term cardiac illness (morbidity) and death (mortality) in people undergoing major non-cardiac vascular surgery.
Study characteristics
We identified two studies that evaluated beta-blockers giving during surgery (perioperatively) in people undergoing major non-cardiac vascular surgery, with follow-up data on cardiovascular outcomes. A total of 599 participants were randomised to receive beta-blockers (301 participants) or placebo (298 participants). Both studies were double-blind
(neither participants nor surgeon were aware of the treatment),
randomised controlled trials evaluating the beta-blocker, metoprolol.
Key results
The results of the analysis offered no clear evidence that perioperative beta-blockers reduced death from any cause (all-cause mortality), cardiovascular death, non-fatal heart attack, irregular heartbeat (arrhythmia), heart failure, stroke, combined cardiovascular events or re-hospitalisation at 30 days. There was evidence to support that beta-blockers increased the risk
of intra-operative low heart rate (bradycardia) and low blood pressure
(hypotension). These complications should be weighed with any benefit
when considering the use of beta-blockers in this population.
Quality of the evidence
Study quality was good for both trials. One trial did not adequately describe their randomisation techniques and the other trial did not report whether the outcome assessors were blinded to the treatment group, and was possibly underpowered. With only two studies included, several of the outcomes only had data from a single study, and neither of the studies reported on blockage or obstruction of blood vessels (vascular patency/graft occlusion), reducing the quality of evidence to moderate.