Although lacking research to support it, a standard protocol is for doctors to prescribe two types of drugs ? ? blockers and statins – to prevent such complications. They are given shortly before, during, or after surgery (the perioperative stage) to help lower blood pressure.
But doctors in Australia now warn that the benefit of using these drugs at this time remains unclear. They cite several large international studies that found no benefit from perioperative ? blockers, but do show that patients can suffer dangerous side effects from the drugs. The warning is published in the British Medical Journal.
Globally, each year about 100 million adults have non-cardiac surgery (ie. surgery not on the heart). About1% of those are at risk of cardiac complications from the surgery, such as heart attacks and strokes. Of those, about one in four will die each year. This works out to be about 250,000 people dying each year after surgery from heart complications.
Two studies from Denmark and the UK 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 ? blockers. Another study found no benefit six months after surgery, and a trial currently underway has so far not reported any beneficial effects.
However, all studies did report significantly higher rates of important side effects with ? blockers, including slow heart beat (bradycardia) and very low blood pressure (hypotension).
Like ? blockers, statins have also been advocated to reduce the risk of perioperative cardiac complications, write the authors. Non-randomised trials suggest that statins confer benefit, but the evidence remains weak, and to prove a strong overall survival benefit would require a ‘gold-standard’ randomised controlled trial of more than 12,000 patients.
This has led to calls to examine the widespread use of perioperative ? blocking drugs. Robust evidence to confirm that these drugs are valuable for routine perioperative use has not been published, researchers say.