The full results of a trial show that people with chronic kidney disease can reduce their heart risk by taking a combination drug that lowers levels of ‘bad’ cholesterol.
Taking cholesterol-lowering drugs such as statins to combat heart disease is pretty standard in people without kidney problems.
But there was a great deal of uncertainty about using such treatments in people with impaired kidney function because of concerns about drug toxicity (the kidneys are key in getting rid of harmful substances). This is despite kidney patients being at high risk of heart problems.
The study findings were first reported at an American Society of Nephrology conference in Denver in November, and in our news story at the time, but the full results have now been published in The Lancet.
The SHARP trial found that patients receiving the daily pill – a combination of simvastatin and ezetimibe produced by Merck – had one-sixth fewer heart attacks, strokes or operations to unblock arteries than those receiving a placebo ‘dummy’ pill. And importantly, there were no safety concerns with the drug, which is already being taken by many people with normal kidney function to lower their cholesterol.
Professor Colin Baigent of the Clinical Trial Service Unit (CTSU) at Oxford University, the trial’s principal investigator, says: ‘This is good news for kidney patients. People with this disease are in desperate need of new treatments not only to combat the disease itself, but also to reduce pain and suffering, such as heart attacks and strokes, due to side effects of the illness.
‘Over half of people with kidney disease will eventually be killed, not by their kidney disease, but by cardiovascular diseases. We now know there is something we can do about this – and I believe this study will have a positive impact on the lives of many millions of people currently being treated for chronic kidney disease in the UK and around the world.’
Chronic kidney disease is very common, affecting up to one in twenty of the middle-aged population, and substantially more of those who are older. Although people with chronic kidney disease are known to have an increased risk of a stroke or heart attack, it has been very unclear what treatments could prevent these conditions in this group of patients.
Dr Martin Landray, co-principal investigator of the trial at CTSU, says: ‘Some doctors had thought that damaged kidneys might cause a type of cardiovascular disease that would not be preventable by lowering cholesterol, but the SHARP trial showed clearly that lowering cholesterol does reduce the risk of cardiovascular disease in people with kidney disease.’
The culmination of this long-running, large-scale trial involving 9,500 patients in 18 countries – planning for which began in the 1990s – marks the end of work in which Colin Baigent has had a great personal interest.
He developed kidney disease himself 30 years ago and needed dialysis before receiving a kidney transplant. He is clear that, ‘Many of the young people who were receiving dialysis at the same time as me are now dead from cardiovascular disease.
‘Progress in the prevention of cardiovascular disease with drug treatments in kidney patients has lagged behind other patient groups,’ he says. ‘The research community has tended to neglect testing promising treatments in kidney patients, partly because of fears that some drugs may turn out to be dangerous in people with damaged kidneys.
‘The SHARP study now shows clearly, however, that it is possible to find safe and effective drugs for the prevention of cardiovascular disease in kidney patients.’
With over 3% of the NHS budget currently devoted to treating kidney patients, and that figure likely to rise, there is a need for better care of such patients, and the prevention of cardiovascular disease should be a high priority, says Colin Baigent.