BARCELONA – Oral anticoagulation had a net overall benefit for patients with atrial fibrillation and advanced chronic kidney disease, based on results of a large observational study reported at the annual congress of the European Society of Cardiology.
The novel direct-acting oral anticoagulants (NOACs) and warfarin were all similarly effective in this study of 39,241 patients who had stage 4 or 5 chronic kidney disease (CKD), atrial fibrillation, and were not on dialysis. Compared with no oral anticoagulation, the drugs cut in half the risk of stroke or systemic embolism, with no increased risk of major bleeding.
“In patients with advanced CKD, it appears that OACs [oral anticoagulants] are reasonable,” concluded, of the Mayo Clinic in Rochester, Minn.
This is a potentially practice-changing finding given the “striking underutilization” of OACs in advanced CKD, he noted. Indeed, only one-third of the patients in this study were prescribed an OAC and picked up their prescriptions. And while the study has the limitations inherent to an observational study reliant upon data from a large U.S. administrative database – chiefly, the potential for residual confounding because of factors that couldn’t be adjusted for statistically – these real-world data may be as good as it gets, since patients with advanced CKD were excluded from the pivotal trials of the NOACs.
Apixaban (Eliquis) was the winner in this study: It separated itself from the pack by reducing the major bleeding risk by 57%, compared with warfarin, although it wasn’t significantly more effective than the other drugs in terms of stroke prevention. In contrast, the major bleeding rates for dabigatran (Pradaxa) and rivaroxaban (Xarelto) weren’t significantly different from warfarin in this challenging patient population.
In a related analysis of 10,712 patients with atrial fibrillation and advanced CKD who were on dialysis, use of an OAC was once again a winning strategy: It resulted not only in an impressive 58% reduction in the risk of stroke or systemic embolism, but also a 26% reduction in the risk of major bleeding, compared with no OAC.
Here again, apixaban was arguably the drug of choice. None of the 125 dialysis patients on apixaban experienced a stroke or systemic embolism. In contrast, dabigatran and rivaroxaban were associated with greater than threefold higher stroke rates than in patients on warfarin, although these differences didn’t achieve statistical significance because of small numbers, just 36 patients on dabigatran and 56 on rivaroxaban, the cardiologist continued.
For these analyses of the relationship between OAC exposure and stroke and bleeding outcomes, Dr. Noseworthy and his coinvestigators used propensity scores based upon 59 clinical and sociodemographic characteristics.
Asked why rates of utilization of OACs are so low in patients with advanced CKD, Dr. Noseworthy replied that he didn’t find that particularly surprising.
“Even if you look only at patients without renal dysfunction, there is incredible undertreatment of atrial fibrillation with OACs. And adherence is very poor,” he observed.
Moreover, in talking with nephrologists, he finds many of them have legitimate reservations about prescribing OACs for patients with end-stage renal disease on hemodialysis.
“They’re undergoing a lot of procedures. They’re having a ton of lines placed; they’re having fistulas revised; and they have very high rates of GI bleeding. In some studies the annual risk of bleeding is 20%-40% in this population. And they’re a frail population with frequent falls,” Dr. Noseworthy said.
He reported having no financial conflicts of interest regarding his study, which was conducted free of commercial support.
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