NEWS Patients with advanced chronic kidney disease or dialysis treatment are often overlooked in drug studies. New blood thinners, so-called DOAK, could be an attractive alternative to the traditional substance warfarin, even in advanced kidney disease or dialysis treatment, according to a thesis.
It focuses on this patient group and investigates whether blood-thinning drugs protect against stroke due to blood clots. The results show that blood thinners could be protective against stroke, but that the risk of simultaneous bleeding is significant. The thesis has also concluded that both clots and bleeding are common in so-called nephrotic syndrome, a condition of kidney disease when a lot of protein is lost in the urine.
Chronic kidney disease occurs in approximately 6-10% of the population, and this patient group is increasing. Globally, it is estimated that chronic kidney disease will be the 5th leading cause of death by 2040. Patients with chronic kidney disease are more likely to suffer from cardiovascular disease, including stroke, and if you also have atrial fibrillation, the risk of stroke increases even more.
In a general population with atrial fibrillation, treatment is often given with blood-thinning drugs to reduce the risk of stroke. Patients with advanced chronic kidney disease or dialysis treatment have unfortunately been virtually excluded from the large drug studies of blood-thinning drugs.
"The aim of the thesis has been to study the benefits and risks of blood thinners, both the traditional substance warfarin and newer blood-thinning drugs, so-called DOAKs," says the author of the thesis, Frida Welander.
"More than 12,000 patients with chronic kidney disease and atrial fibrillation have been identified via the Swedish Kidney Register and the Patient Register, and we have studied how different blood-thinning treatments differ with regard to stroke (due to clots) and bleeding.”
Warfarin seems to provide stroke protection but an increased risk of bleeding, a risk that is basically already high. DOAK appears to confer a lower risk of bleeding with a similar stroke risk compared to warfarin. Previously published studies on this topic have had poor quality of warfarin treatment, and this leads to difficulties in interpreting the results. The studies included in the thesis have for the first time compared high-quality warfarin treatment with both DOAK and no treatment in patients with chronic kidney disease. The studies highlight the importance of good quality of the blood-thinning treatment, but also illustrate the high risk of bleeding. Bleeding appears to be more common than stroke due to thrombosis in patients with advanced chronic kidney disease or dialysis treatment, and prescribing blood thinners should therefore be restrictive to these patients.
"The results are an important piece of the puzzle in how we best protect the large group of patients with chronic kidney disease from cardiovascular disease and death. However, there are still many unanswered questions. Fortunately, larger randomised drug trials for dialysis patients are now underway, and these will be able to provide us with more answers within a few years," says Frida Welander.
Frida Welander grew up in Dalarna, studied medicine in Uppsala before moving to Stockholm and doing her internship and starting a specialist training in nephrology. In 2018, she and her family moved to Sundsvall, where she now works as a specialist physician at the medical clinic's kidney section. She started as a doctoral student in 2019 and hopes to continue her research career even after her dissertation.
On Friday 1 December, Frida Welander, Department of Public Health and Clinical Medicine at Umeå University, defends her thesis Blood thinners in kidney disease. The dissertation will take place at 09:00 in the Auditorium, Sundsvall Hospital. Opponent is Associate Professor Marie Evans, Karolinska Hospital.
