Should my patient with non-valvular atrial fibrillation on hemodialysis be anticoagulated?

Whether patients with end-stage kidney disease (ESKD) and non-valvular atrial fibrillation (AF) benefit from anticoagulation is a matter of controversy. 1,3 Although there may be some suggestion of benefit of warfarin for stroke prevention in this patient population, 2 there is also a higher concern for bleeding. 4-6 An increased risk of stroke among patients with ESKD and AF on warfarin has also been reported. 7

A 2018 Kidney Disease:Improving Global Outcomes (KDIGO) Controversies Conference concluded that there is “insufficient high-quality evidence” to recommend anticoagulation for prevention of stroke in patients with ESKD and atrial fibrillation. 8

However, the 2014 American College of Cardiology (ACC)/American Heart Association (AHA)/ Heart Rhythm (HRS) guideline states that it is reasonable to consider warfarin therapy in patients with ESKD and non-valvular AF with CHA2DS2 -VASc score of 2 or greater (Class IIa recommendation, level of evidence B).8 Of interest, the FDA recently approved the use of a direct oral anticoagulant (DOAC), apixaban, in ESKD potentially providing an alternative to the use of warfarin when anticoagulation is considered.10

Perhaps the decision to anticoagulate patients with ESKD for atrial fibrillation is best made on a case-by-case basis taking into account a variety of factors, including the risk of thromboembolic event, the risk of bleeding complications as well as patient preference.


1. Genovesi S, Vincenti A, Rossi E, et al. Atrial fibrillation and morbidity and mortality in a cohort of long-term hemodialysis patients. Am J Kidney Dis 2008;51:255-62.

2. Olesen JB, Lip GY, Kamper AL, et al. Stroke and bleeding in atrial fibrillation with chronic kidney disease. N Engl J Med 2012;367:625-35.

3. Shah M, Avgil TM, Jackevicius CA, et al. Warfarin use and the risk for stroke and bleeding in patients with atrial fibrillation undergoing dialysis. Circulation2014;129:1196-203.

4. Elliott MJ, Zimmerman D, Holden RM. Warfarin anticoagulation in hemodialysis patients: a systematic review of bleeding rates. Am J Kidney Dis 2007;50:433-40.

5. Holden RM, Harman GJ, Wang M, Holland D, Day AG. Major bleeding in hemodialysis patients. Clin J Am Soc Nephrol 2008;3:105-10.

6. Wizemann V, Tong L, Satayathum S, et al. Atrial fibrillation in hemodialysis patients: clinical features and associations with anticoagulant therapy. Kidney Int 2010;77:1098-106.

7. Chan KE, Lazarus JM, Thadhani R, Hakim RM. Warfarin use associates with increased risk for stroke in hemodialysis patients with atrial fibrillation. J Am Soc Nephrol2009;20:2223-33.

8. Turakhia MP, Blankestijn PJ, Carrero J, et al. Chronic kidney disease and arrythias: conclusions from a Kidney Disease:Improving Global Outcomes (KDIGO) Controversies Conference. Eur Heart J, ehy060. Published 07 March 2018.

9. January CT, Wann LS, Alpert JS, et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation. Circulation 2014;130:2071-104. 

10. Moll S. Use of direct oral anticoagulants in patients on hemodialysis. Diffusion, October 11, 2017. 

Contributed by Brad Lander, MD, Mass General Hospital, Boston, MA.

Should my patient with non-valvular atrial fibrillation on hemodialysis be anticoagulated?

Does hypertension cause epistaxis?

Although traditionally we think of epistaxis as a potential sign of hypertension, particularly when severe, whether hypertension causes epistaxis is unclear and even the association of these 2 conditions has been challenged in recent years.

A 2014 systematic review found that although the majority of studies reported an association between these 2 conditions, many did not include a control group, were of poor methodological quality and did not adjust for confounding variables such as age, sex, and anticoagulation1.  Indeed, a larger study that controlled for many potential confounding factors failed to confirm such an association2.  A small prospective study also found no correlation between the severity of hypertension and epistaxis3.

Even when an association between hypertension and epistaxis has been found, it is unclear how much of the stress of bleeding itself and white coat syndrome may affect the readings1. However, an interesting 2017 study found masked hypertension (normal blood pressure in office, abnormal on ambulatory measurements) in 33.3% of patients with epistaxis with night time blood pressures that were significantly higher among patients with epistaxis4.

So the data is all over the place! It makes sense that long standing hypertension through its effects on blood vessels such as atherosclerosis and endothelium dysfunction may set the stage for epistaxis1,5, particularly in our ever-aging population on anticoagulants.  But whether hypertension by itself is enough to cause epistaxis is likely to be debated for years to come.  



  1. Kikidis D, Tsioufis K, Papanikolaou V, et al. Is epistaxis associated with arterial hypertension? A systematic review of the literature 2014;271:237-243.
  2. Fuchs FD, Moreira LB, Pires CP, et al. Absence of association between hypertension and epistaxis: a population-based study. Blood Press 12:145-48.
  3. Knopfholz J, Lima-Junior E, Précoma-Neto D, et al. Association between epistaxis and hypertension: A one year follow-up after an index episode of nose bleeding in hypertensive patients. Internat J Cardiol 2009;134:e107-e109.
  4. Acar B, Yavuz B, Yildiz E, et al. A possible cause of epistaxis: increased masked hypertension prevalence in patients with epistaxis. Braz J Otorhinolaryngol 2017;83:45-49.
  5. Celik T, Iyisoy A, Yuksel UC, et al. A new evidence of end-organ damage in the patients with arterial hypertension: epistaxis? Internat J Cardiol 2008;141:105-107.
Does hypertension cause epistaxis?

Does electroconvulsive therapy (ECT) pose a risk of embolic stroke in patients with atrial fibrillation (AF)?

Acute embolic stroke in the setting of AF without anticoagulation after ECT has been reported in a single case report in the absence of conversion to normal sinus rhythm (1). Several cases of episodic or persistent conversion to normal sinus rhythm (NSR) in patients with AF undergoing ECT have also been reported (in the absence of embolic stroke), leading some to recommend anticoagulation therapy in such patients (2), though no firm data exist.

The mechanism by which ECT promotes cardioversion from AF to NSR is unclear as direct electrical influence of ECT on the heart is thought to be negligible (1). Arrhythmias such as atrial flutter and AF have also been reported after ECT (1). Curiously, ECT is associated with increased 5- hydroxytryptamine (5- HT2)-receptor densities of platelets in patients with depression which may enhance platelet reactivity and increase the risk of embolic stroke (3) even in the absence of cardioversion.



  1. Suzuki H, Takano T, Tominaga M, et al. Acute embolic stroke in a patient with atrial fibrillation after electroconvulsive therapy. J Cardiol Cases 2010; e12-e14.
  2. Petrides G, Fink M. Atrial fibrillation, anticoagulation, electroconvulsive therapy. Convulsive Therapy 1996;12:91-98.
  3. Stain-Malmgren R, Tham A, Ǻberg-Wistedt A. Increased platelet 5-HT2 receptor binding after electroconvulsive therapy in depression. J ECT 1998;14:15-24.
Does electroconvulsive therapy (ECT) pose a risk of embolic stroke in patients with atrial fibrillation (AF)?

How should I choose between the novel oral anticoagulants (NOACs)?

Although warfarin has long been the standard treatment for venous thromboembolism (VTE) and thomboprophylaxis in atrial fibrillation (AF), the need for its frequent monitoring, potential drug interactions, and narrow therapeutic window made it far from ideal. Since 2009, NOACs have become viable alternative agents owing to their more predictable and safer pharmacological profiles. NOACs include several direct factor Xa inhibitors (apixaban, rivaroxaban, edoxaban) and a direct thrombin inhibitor (dabigatran). Approved indications include: (1) thromboprophylaxis in nonvalvular AF; (2) treatment of deep venous thrombosis or pulmonary embolism; and (3) primary prevention of postoperative VTE. 

Compared to warfarin, NOACs are associated with a reduced risk of intracranial hemorrhage, and in the case of apixaban, lower risk of gastrointestinal bleeding; rivaroxaban and edoxaban have been associated with a higher risk of gastrointestinal bleeding.   Apixaban is also the only NOAC whose dose can be safely reduced in chronic kidney disease, including those on hemodialysis. 



1. Baber U, Mastoris I, and Mehran R. Balancing ischaemia and bleeding risks with novel oral anticoagulants. Nat Rev Cardiol 2014;11:693-703. 

2. Ansell JE. Universal, class-specific, and drug-specific reversal agents for the new oral anticoagulants. J Thromb Thrombolysis 2016;41:248-52.


Contributed by William L. Hwang, MD, Mass General Hospital, Boston, MA

How should I choose between the novel oral anticoagulants (NOACs)?

Is anticoagulation (AC) therapy recommended for treatment of vein thrombosis of upper extremities?

The short answer is “yes” when deep veins, such as brachial, axillary or subclavian are involved; cephalic and basilic veins are superficial. Although some have suggested that isolated brachial vein thrombosis may be considered at low risk of complication, this assumption has not been corroborated by objective research (1).

There are no randomized trials of AC therapy in patients with upper extremity deep vein thrombosis (UEDVT).  However,  the American College of Chest Physicians has recommended a 3-month course of AC therapy similar to that of leg DVT for several reasons (1,2):

  •  UEDVT has generally been reported to have complications and consequences comparable to that of leg DVT
  •  Several small cohort studies suggest lower rates of recurrent DVT, PE, and bleeding when UEDVT is treated similar to leg DVT
  •  Known demonstrated benefit of AC therapy in leg DVT

In addition, post-thrombotic syndrome is relatively common (~1 in 5) among patients with UEDVT (3)


1.  Hingorani A, Ascher E, Marks N, et al. Morbidity and mortality associated with brachial vein thrombosis. Ann Vasc Surg 2006; 20:297-299.

2. Kearon C, Akl EA, Comerato AJ, et al. Antithrombotic therapy for VTE disease: American College of Chest Physicians Antithrombotic Therapy and Prevention of Thrombosis Panel. Antithrombotic therapy for VTE disease: antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest 2012;141(suppl):419S-494S.

3. Maynard G. Upper extremity deep vein thrombosis:A call to arms. JAMA Intern Med 2014;696-698.

Is anticoagulation (AC) therapy recommended for treatment of vein thrombosis of upper extremities?

Is bridging anticoagulation necessary perioperatively in patients with non-valvular atrial fibrillation (AF)?

Until recently, there were no randomized-controlled trials (RCTs) available to help guide our decision.  A recent RCT, however, demonstrated that foregoing bridging anticoagulation was not inferior to bridging with low-molecular-weight heparin in patients with chronic or paroxysmal AF for the prevention of arterial thromboembolism and decreased the risk of major bleeding (1).  Ineligibility criteria included mechanical valve; stroke, systemic embolism, or transient ischemic attack within the previous 12 weeks; major bleeding within the previous 6 weeks; creatinine clearance < 30 ml/min; platelet count < 100K/ cubic ml; or planned cardiac, intracranial, or intraspinal surgery.  A caveat is that the study included relatively few patients (<5%) with CHADS2 score >4.

Douketis JD, Spyropoulos AC, Kaatz S, et al. Perioperative bridging anticoagulation in patients with atrial fibrillation. N Engl J Med 2015 (published June 22 at

Is bridging anticoagulation necessary perioperatively in patients with non-valvular atrial fibrillation (AF)?

Is there anyway to predict a significant rise in INR from antibiotic use in patients who are also on warfarin?

Not really!  Many of the commonly used antibiotics have the potential for increasing the risk of major bleeding through disruption of intestinal flora that synthesize vitamin K-2 with or without interference with the metabolism of warfarin through cytochrome p450 isozymes inhibition.

Although there may be some inconsistencies in the reports, generally quinolones (e.g. ciprofloxacin, levofloxacin), sulonamides (e.g. trimethoprim-sulfamethoxazole), macrolides  (e.g. azithromycin), and azole antifungals (e.g. fluconazole) are thought to carry the highest risk of warfarin toxicity, while amoxacillin and cephalexin may be associated with a more modest risk (1,2).  Metronidazole can also be a culprit (2).


1. Baillargeon J, Holmes HM, Lin Y, et al. Concurrent use of warfarin and antibiotics and the risk of bleeding in older adults. Am J Med. 2012 February ; 125(2): 183–189.

2. Juurlink DN. Drug interactions with warfarin: what every physician should know. CMAJ, 2007;177: 369-371.

Is there anyway to predict a significant rise in INR from antibiotic use in patients who are also on warfarin?