Experts have called into question the routine use of drugs to prevent heart complications during surgery in a report featured in this week’s British Medical Journal.
Around 100 million adults around the world have non-cardiac surgery each year. One in 100 is at risk of cardiac complications, such as heart attacks and strokes, and about one in four hundred will die each year.
Two types of drugs – beta blockers and statins – are regularly given to patients to prevent such complications and they are given shortly before, during, or after surgery to help lower blood pressure. But now doctors in Australia have warned that the benefit of using these drugs at this time remains unclear.
They cite several large international studies that found no benefit from perioperative beta blockers. Clinical trials from Denmark and the UK have reported no reduction in death or several other serious complications, such as heart attack, heart failure, and stroke 30 days after surgery in patients receiving beta blockers.
Another study found no benefit six months after surgery, and a trial currently underway has so far not reported any beneficial effects but all of the studies did report significantly higher rates of significant side effects with beta blockers, including bradycardia and hypotension.
This has led Stephen Bolsin of the University of Melbourne and colleagues to question the widespread use of perioperative beta blocking drugs. Like beta blockers, statins have also been advocated to reduce the risk of perioperative cardiac complications and the Australian doctors note that non-randomised trials suggest that statins confer benefit, but that the evidence remains weak. They say that proof of overall survival benefit would require a ‘gold-standard’ randomised controlled trial of more than 12,000 patients.
The benefits of statins in reducing cardiac complications in the general population and high-risk patients are well known, but robust evidence to confirm that these drugs are valuable in routine perioperative use has not been published, the researchers say. They note too that, statins “are associated with serious liver and muscle toxicity, although these are rare in perioperative use”.
In conclusion they say: “We suggest that patients already receiving beta blockers or statins before surgery should continue with treatment. Only patients who need heart or blood pressure control, or both in the perioperative period should start treatment with beta blockers. No patient should start taking statins in the perioperative period specifically to reduce the likelihood of perioperative cardiac events.” By Michael Day