When is the right time to start thinking about renal function in patients with AF?
Patient case: When does renal function begin to affect prognosis?
Think about the following clinical situation:
- Alex is a 66-year-old building site foreman, who is approaching retirement with enthusiasm
- He cheerfully admits that his diet is not the best and that after “years of trudging around building sites”, he plans to spend his retirement relaxing on the sofa at home
- Following spells of dizziness and heart palpitations, Alex was discovered to be hypertensive and was subsequently diagnosed with non-valvular atrial fibrillation (AF). He was prescribed an anticoagulant for stroke prevention
- His estimated glomerular filtration rate is currently 82 ml/min/1.73 m2
Because Alex is a candidate for non-vitamin K antagonist oral anticoagulant (NOAC) treatment, his renal function was tested to check whether he would require dose reduction and, while his estimated glomerular filtration rate indicates mild renal impairment, it might not be considered severe enough to substantially worsen his prognosis or require special management.
Given this, why should you consider renal impairment at all?
Renal function is an issue for all patients with AF
AF is associated with an increased risk of a progressive decline in renal function for all patients and, once they have renal dysfunction, patients with AF are much more likely to progress to end-stage renal disease than those without.1-3
Renal function also declines naturally with age, meaning that there are unlikely to be improvements when a patient has reached the stage of impaired function.4
Once renal function has been lost, it can rarely be replaced.5
Further compounding the issue, the rate of renal function decline doubles in patients with diabetes.6 This is a significant complication because diabetes is also a common co-morbidity of AF.7 Given that Alex will soon be retiring from a relatively active job, and the known risk factors associated with his lifestyle, type II diabetes is likely to be a concern in the near future.
Once a patient with AF develops renal disease, their risk of stroke/systemic embolism (SE) increases by 50%, and the chance that they will have a bleeding event doubles.8 Therefore, it is of utmost importance to slow or prevent the development and progression of renal disease in a patient like Alex. Further information on the burden of renal impairment in AF can be found here.
The interaction of AF, existing renal impairment and diabetes increases the risk of worsening renal function and stroke/SE.1,2,6,8,9
What can be done early to prevent renal function decline?
Each of the currently available NOACs (apixaban, dabigatran, edoxaban and rivaroxaban) have demonstrated efficacy and safety in patients with AF,10-13 and these results were unaffected by the presence of renal impairment.14-17 There is also evidence that some NOACs may be associated with a reduced risk of adverse renal outcomes compared with vitamin K antagonists (VKAs).18,19
Further encouraging data were found in a subset of patients with AF who were at increased risk of stroke/SE due to a combination of impaired renal function and diabetes. The NOACs continued to demonstrate comparable efficacy and safety compared with VKAs in this group,20,21 with evidence indicating that the NOACs may also have preserved renal function compared with VKAs.20
The 2019 update to the American Heart Association/American College of Cardiology/Heart Rhythm Society guidelines acknowledges that the NOACs, particularly rivaroxaban and dabigatran, may be associated with a lower risk of adverse renal outcomes than VKAs in patients with AF.22 When stroke/SE prevention, risk of bleeding and renal preservation are considered in totality, the NOACs present an appealing treatment option for those with AF.
Summary
AF is linked to a range of co-morbidities, and it is important that clinicians consider not just those presenting now, but also those which may potentially occur in the future. Of these, it is crucial to consider the patient’s kidneys, not only due to the negative interplay between AF, renal dysfunction and diabetes, but because patients will not regain renal function once it is lost. Preservation is therefore key.
Patients like Alex are typical of those seen daily in clinical practice. While Alex’s presentation is common, it is still important that the full range of disease factors are considered when treating him. While there are no current concerns with Alex’s renal function, careful treatment now could help to ensure that this remains the case.
- Bansal N et al. Circulation 2013;127:569–574. Return to content
- Bansal N et al. Clin J Am Soc Nephrol 2016;11:1189–1196. Return to content
- Watanabe H et al. Am Heart J 2009;158:629–636. Return to content
- Denic A et al. Adv Chronic Kidney Dis 2016;23:19–28. Return to content
- Weis L et al. PLoS One 2013;8:e81835. Return to content
- Sheen YJ, Sheu WH. World J Diabetes 2014;5:835–846. Return to content
- Bassand JP et al. PLoS One 2018;13:e0191592. Return to content
- Olesen JB et al. N Engl J Med 2012;367:625–635. Return to content
- The Stroke Risk in Atrial Fibrillation Working Group. Neurology 2007;69:546–554. Return to content
- Patel MR et al. N Engl J Med 2011;365:883–891. Return to content
- Granger CB et al. N Engl J Med 2011;365:981–992. Return to content
- Connolly SJ et al. N Engl J Med 2009;361:1139–1151. Return to content
- Giugliano RP et al. N Engl J Med 2013;369:2093–2104. Return to content
- Hijazi Z et al. Circulation 2014;129:961–970. Return to content
- Bohula EA et al. Circulation 2016;134:24. Return to content
- Fox KAA et al. Eur Heart J 2011;32:2387–2394. Return to content
- Hohnloser SH et al. Eur Heart J 2012;33:2821–2830. Return to content
- Yao X et al. Am J Cardiol 2017;70:2621–2632. Return to content
- Bonnemeier H et al. ESOC. Milan, Italy, 22–24 May 2019, Abstract AS25-066. https://journals.sagepub.com/toc/esoa/4/1_suppl [accessed 05 June 2020]. Bonnemeier H et al. ESOC. Milan, Italy, 22–24 May 2019, Abstract AS25-066. https://journals.sagepub.com/toc/esoa/4/1_suppl [accessed 05 June 2020]. Return to content
- Bonnemeier H et al. ESOC. Milan, Italy, 22–24 May 2019, AS25-069. https://journals.sagepub.com/toc/esoa/4/1_suppl [accessed 05 June 2020]. Bonnemeier H et al. ESOC. Milan, Italy, 22–24 May 2019, AS25-069. https://journals.sagepub.com/toc/esoa/4/1_suppl [accessed 05 June 2020]. Return to content
- Vaitsiakhovich T, Coleman CI, Kleinjung F et al. Worsening of renal function in atrial fibrillation patients with stage 3 or 4 chronic kidney disease treated with warfarin or rivaroxaban - evidence from the real-world CALLIPER study in the US claims. European Society of Cardiology Congress. Paris, France, 31 August–5 September 2019, Poster P4746. Available at: https://academic.oup.com/eurheartj/article-abstract/40/Supplement_1/ehz745.1122/5596296?redirectedFrom=fulltext [accessed 28 February 2020]. Vaitsiakhovich T, Coleman CI, Kleinjung F et al. Worsening of renal function in atrial fibrillation patients with stage 3 or 4 chronic kidney disease treated with warfarin or rivaroxaban - evidence from the real-world CALLIPER study in the US claims. European Society of Cardiology Congress. Paris, France, 31 August–5 September 2019, Poster P4746. Available at: https://academic.oup.com/eurheartj/article-abstract/40/Supplement_1/ehz745.1122/5596296?redirectedFrom=fulltext [accessed 28 February 2020]. Return to content
- January CT et al. Circulation 2019;140:e125–e151. Return to content