Science
Patients with kidney failure at ‘unacceptably’ high risk of heart attack and stroke, study finds
People with kidney failure are many times more likely to have a heart attack or stroke than the general population and have a higher risk of dying as a result, according to research funded by the British Heart Foundation (BHF) published today in the European Heart Journal.
The first analysis of nationwide kidney failure patient data over 20 years showed that these patients are up to eight times more likely to have a heart attack and up to four times more likely to have a stroke than those without the condition, with women having a greater risk than men.
However, the study also offers hope that cheap and simple treatment strategies could help improve survival rates for people with kidney failure who have had a heart attack or stroke. The research reveals that over 40% of patients who were not prescribed dual anti-platelet drugs died of a heart-related problem within a year, whereas the figure dropped to nearly 14% for those who were given the medications.
Urgent improvement needed
Anti-platelet drugs are commonly prescribed to the general population after a heart attack or stroke to prevent blood clotting.
Professor Neeraj Dhaun (Bean), Professor of Nephrology at the University of Edinburgh, who was involved in the research, said: “Kidney failure patients are typically excluded from trials of post-heart attack or stroke treatments, like anti-platelet drugs, that become standard for other groups. The resulting lack of data to prove the drugs are safe and effective means there is an understandable reluctance from many doctors to prescribe them for this very high-risk group.
“However, our results do show that anti-platelet drugs are being prescribed more often for kidney failure patients in recent years and this could bring with it huge improvements in the rate of survival.
“There is an urgent need for a clinical trial of these, and similar, drugs in kidney failure patients. By determining whether they are truly safe and effective we could potentially bring about a much-needed improvement in treatment for these people.”
It’s estimated that one in 10 people in the UK are affected by chronic kidney disease, a long-term progressive condition where the kidneys don’t work as well as they should. Over 70,000 people in the UK are currently being treated for kidney failure, the final stage of the disease. Kidney disease patients are at higher risk of heart attacks and strokes than the general population. Their risk increases as their kidney function declines and is highest in patients with kidney failure.
This study was the first to assess whether heart attack and stroke rate, treatments and survival had improved for kidney failure patients over 20 years. The researchers used anonymised healthcare data from over 16,000 Scottish kidney failure patients from 1996 to 2016.
“Progress under threat”
The rate of heart attacks and strokes halved in kidney failure patients over the 20 years, and the number of deaths because of them also fell. But this drop lagged behind the large decreases seen in the rest of the population. As a result, the gap is now bigger than it was 20 years ago - even more so for women compared to men. The researchers say that further research is needed to understand the causes of this disparity and how to reduce rates of heart attack and stroke in this group.
Professor Bryan Williams, Chief Scientific and Medical Officer at the British Heart Foundation, said: “This comprehensive study shows that, despite some improvements in recent decades, kidney failure patients are still at an unacceptably high risk of having a heart attack or stroke, and in some cases dying.
“Over the course of this study, which looks at patient data over 20 years, we have seen great progress in heart attack and stroke prevention and treatment for the wider population. But this progress is under threat as premature death rates from heart and circulatory diseases have risen in the UK in the past few years.
“Against this backdrop, much more focused work needs to be done to ensure that kidney failure patients are not left behind when it comes to heart and circulatory disease care.”
"Costing lives"
Fiona Loud, Policy Director at Kidney Care UK, said: “Chronic kidney disease (CKD) affects 1 in 10 people in the UK and the number of people with CKD in the UK is expected to grow significantly over the coming decade because of an ageing population, and increasing prevalence of type 2 diabetes and hypertension.
"All CKD stages are associated with increased risk of death and cardiovascular disease yet data shows that less than 30% of people with high blood pressure are given the appropriate urine tests to identify if their kidneys are working properly. As this study highlights, cheap and simple treatments may have a significant impact on improving survival rates of people with kidney failure who have had a heart attack or stroke.
"Failing to identify people early and make sure they receive all appropriate treatments is costing lives, and we hope that this study will act as a call for improvement. This research also highlights the inequality of vulnerable groups being excluded from clinical trials. The scientific community has a responsibility to improve the designs of clinical trials to enhance equitable access to new treatments, and include people with CKD in clinical trials in order to build an evidence base for treatments for everyone with CKD.”