A short-term daily dose of statins before and after heart surgery does not prevent heart complications, according to an international clinical trial we funded at the University of Oxford.
The trial, which is the largest of its kind, showed that a daily dose of statins for a few days before and after heart surgery did not prevent heart damage or atrial fibrillation (AF) and increased the risk of developing kidney damage. These results, published today in the New England Journal of Medicine (NEJM), rule out a clinical benefit of statin therapy in heart surgery and are expected to change international guidelines on preventing AF and other in-hospital complications after heart surgery.
However, the findings do not challenge the strong evidence that long-term treatment with statins reduces heart attack and stroke risk by lowering the levels of 'bad' LDL cholesterol in the blood.
We answer your questions on statins in our Heart Matters magazine.
What is atrial fibrillation?
Atrial fibrillation is an increasingly common heart rhythm disorder. Over 1.1million people in the UK have been diagnosed with AF and hundreds of thousands more are estimated to be undiagnosed. AF can cause palpitations (being aware of your heartbeat), tiredness, dizziness or feeling faint, and shortness of breath. But the major concern with AF is that it increases the risk of a stroke by around four to five times.
AF is a frequent complication of cardiac surgery. Current guidelines recommend a short course of statins to prevent the development of AF, but the evidence to support this practice is limited.
BHF Professor Barbara Casadei (pictured), who led the research at the University of Oxford and is a consultant cardiologist at the John Radcliffe Hospital, said: "Statins have been known to have rapid anti-inflammatory and antioxidant effects for many years. It was important to establish whether such effects would translate into patient benefit in conditions accompanied by a strong inflammatory response, such as heart surgery."
The BHF-funded study
The trial, called Statin Therapy In Cardiac Surgery (STICS), involved randomly giving 1,922 people scheduled for heart surgery either a daily dose of a statin (rosuvastatin 20 mg daily) or a matching placebo tablet. These people had a normal heart rhythm, so did not have AF before surgery, and received their tablets for up to eight days before surgery and for five days afterwards.
The heart patients were recruited and treated in China at the Fuwai Hospital. Patient randomisation and analysis of the data and samples collected was carried out in Oxford. Alongside the BHF, the trial was funded by the European Network for Translational Research in Atrial Fibrillation of the European Commission Seventh Framework Program, the NIHR Oxford Biomedical Research Centre (BRC), and the Medical Research Council (MRC) and by a small unrestricted grant from AstraZeneca.
Study showed no benefits
The researchers found that the rates of AF after surgery were not significantly different between the two groups of patients (21.1 per cent with statin vs. 20.5 per cent with placebo). The levels of the protein troponin I in the blood, which indicates heart damage, were also not significantly different between the patients taking the statin and those taking the placebo.
As well as showing no benefits, short-term statin treatment in these patients caused an increase in the rate of acute kidney injury after surgery (24.7 per cent with statin vs. 19.3 per cent with placebo).
Read about the BHF Professor who is trying to reduce acute kidney injury after heart surgery.
Implications for people having heart surgery
BHF Professor Casadei added: "Although guidelines currently recommend statins at the time of heart surgery to reduce complications, the evidence was not very strong. The results of our large randomised placebo-controlled trial conclusively prove that there are no benefits to taking statins shortly before and after heart surgery to reduce postoperative complications but there is an adverse effect on kidney function.
"As a doctor I want to do everything I can to ensure my patients get the best possible care and minimise any complications that can come from a heart operation. Unfortunately we now know that statins are not the right treatment to minimise AF and heart damage after surgery. We expect these results to rapidly change guidelines around the world to ensure patients receive the best evidence-based care."
Currently just under 17,000 coronary artery bypass graft procedures (heart bypass surgery) are carried out in the UK each year. Most of the people having those operations are already diagnosed with coronary heart disease and are therefore already taking statins. As these results show taking statins before and after heart surgery increases risk of kidney damage, these results suggest doctors should recommend a break from the drug before surgery and that people resume taking their medication a week after the operation.
Are statins safe?
This study does not have any bearing on the safety of taking statins long term to help prevent having a heart attack or stroke. Commenting on the results, our Medical Director, Professor Peter Weissberg, said:
"This study clearly shows that statins should not be given to patients at the time of heart surgery in an attempt to reduce complications like AF. But the study does not negate the wealth of evidence showing that long-term statin treatment reduces the risk of future heart attacks and strokes."
Find out how our research showed the safety and effectiveness of statins.
AF remains a major health problem and there continues to be a risk of developing it as a result of heart surgery. More research is needed to develop better treatments for AF and to improve heart surgery so it results in fewer complications.
Professor Weissberg said: "The BHF continues to fund research into reducing the complications from surgery and, with BHF support, Professor Casadei is finding better ways to manage AF. We urgently need better ways of preventing this dangerous heart rhythm disorder that can lead to strokes, and research is helping us to find them."
Help us to continue funding research to improve treatments for atrial fibrillation by donating today.