October 15th, 2012

Stable Anticoagulation, Unstable Gait


A 91-year-old man with mild drug-controlled hypertension and atrial fibrillation has long-term, well-managed stability on warfarin anticoagulation. After developing problems with his balance and some gait instability, a physical exam reveals a carotid bruit. Carotid ultrasound and magnetic resonance angiography (MRA) confirm >95% stenosis of the right internal carotid artery. Brain CT is negative.


1.      What should this man’s anticoagulation regimen be?
2.      What would you recommend for the ICA stenosis?
3.      Would you perform brain MRA?


James Fang, MD

October 22, 2012

This 91-year-old man has developed balance and gait instability that may or may not be explained by the incidentally noted high-grade carotid stenosis. (Intermittent unilateral lower-extremity weakness or sensory loss could result in balance and gait issues but should be confirmed by a careful neurologic exam.) The patient otherwise appears to have few medical issues other than atrial fibrillation. If a detailed neurologic evaluation documents posterior-circulation findings, an MRA of the posterior circulation would be reasonable to establish another diagnosis (e.g., of vertebral-basilar insufficiency).

If no symptoms are clearly attributable to the carotid stenosis, continued management with warfarin anticoagulation and statins is reasonable. The patient’s bleeding risk is modest despite his age. Although he has a risk for falling, such risks are often overestimated. Bleeding risk can be estimated from various scoring systems such as HAS-BLED. Adding aspirin would be likely to increase his bleeding risk without appreciably decreasing the risk for stroke from his carotid stenosis and atrial fibrillation, although aspirin is frequently added in practice.

Some would advocate carotid endarterectomy (CEA), but it typically takes a few years for a stroke-prevention benefit of CEA to be evident in asymptomatic patients. I would advocate CEA if, as noted above, the patient experiences symptoms that can be attributed to his carotid stenosis. His operative risk is acceptable if local expertise in CEA has been associated with a <3% incidence of postoperative stroke or death.


Jeff Dickey, MD

October 29, 2012

The patient’s gait instability was diagnosed by the neurologist as polymyalgia rheumatica. During my exam I apparently didn’t appreciate morning hip stiffness as the basis for gait instability. His symptoms dramatically improved on prednisone.

The neurologist, in consultation with the cardiologist, decided on treatment with 81 mg/day of aspirin and continued warfarin (INR goal, 2-3). The patient is taking omeprazole for the GI risk from the combination of aspirin, prednisone, and warfarin.

A link between temporal arteritis (which may be associated with polymyalgia rheumatica) and carotid stenosis, as documented in case reports, may or may not be relevant to this patient.


19 Responses to “Stable Anticoagulation, Unstable Gait”

  1. Very interesting case, thanks for sharing. According to CHA2DS2-VASc (and even of CHADS2), he should continue anticoagulation.

    1. Continue warfarin therpay. I am not awfully concerned about the risk of falls (http://www.ncbi.nlm.nih.gov/pubmed/22840664) –though asking him and his family for aids that would minimize the risk of falls may be in order.

    2. As for his carotid stenosis, I guess intracranial stenting is of no proven benefit, and there is some suggestion for harm (http://www.ncbi.nlm.nih.gov/pubmed/17050890 [versus endarterectomy] and http://www.ncbi.nlm.nih.gov/pubmed/21899409 [versus medical therapy]). I am unfamiliar with the risks and benefits of endarterectomy versus medical therapy in this case, though.

    3. I would not, as I am unaware of comparative effectiveness studies that have proven benefit from an MRA- guided strategy. But I would be happy to learn, if there is one.

  2. Judith Andersen, AB, MD says:

    Never at a loss for making a fool of myself, I would add aspirin – if he is not already taking it, likely change his anticoagulation regimen to rivaroxaban, perform both a TEE to exclude a cardiac cause of his events ( even well-managed warfarin fails on occasion) and a brain MRA and MRV (if no cardiac cause is identified and his renal function can tolerate it), to understand the balance of cerebral arterial flow , the adequacy of venous outflow, and try to decide whether his right carotid is critical to his CNS well-being. If there is no venous obstruction and carotid stenosis is clearly restricting arterial supply, would ask for advice on the safety of stenting his right carotid. And, of course would consider his wishes for or against aggressive intervention. Will be happy to be educated by colleagues.

  3. Edgar Abovich, MD says:

    I would not change the anticoagulation regimen at this time while trying to determine if the carotid stenosis is contributing to patient’s symptoms. I am not a neurologist but if a patient has ataxia, it is usually vertibrobasilar circulation issue and not carotid. This patient, however, may very well have diffuse cerebrovasculal disease. I would not recommend any interventions for asymptomatic carotid stenosis but it would be reasonable to consider cutting back on the blood pressure meds or even discontinuing it altogether. A brain MRA is not necessary at this time but can be done in the future to confirm the diagnosis if the patient remains symptomatic.
    Would not use rivaroxaban or dabigatran for numerous reasons but the main one is the fact that warfarin has been effective and safe for this patient
    without clinical or CT evidence of embolism. I can see the point in adding ASA but I wouldn’t do it now because the risks may outweigh the benefits, especially considering that patient is progressed to 95% stenosis witout a stoke or TIA.

  4. Bogdan Radakovic, MD says:

    1. There are not enough data to calculate neither CHA2VA2SC nor HASBLED score, so no precise answer can be given.
    Warfarin therapy does not seem to increase bleeding risk among patients with high risk for falls (Donzé J et al. Risk of falls and major bleeds in patients on oral anticoagulation therapy.. Am J Med 2012 Aug; 125:773), therefore instable gait would not be the reason to stop it.
    2. To continue medical therapy
    3. Not, I don’t see how would it afect clinical decisions.

  5. peter kaserer, MD says:

    Continue anticoagulation, leave the ICA alone, no MRA neccessary.
    Have a Good Day

  6. Dan Hackam, MD PhD says:

    I would not add antiplatelet therapy. The WARIS study by JP Mohr showed similar stroke prevention with warfarin or aspirin in patients with a history of ischemic stroke (published about 10 years ago). Adding ASA will increase his risk of bleeding by 2-3-fold, and provide no additional protective benefit. Warfarin does inhibit platelet aggregation by reducing circulating thrombin (which is a platelet agonist). Warfarin therefore prevents both arterial and venous thromboembolism.
    About twenty years ago, a pair of studies confirmed no benefit for antiplatelet therapy for asymptomatic carotid stenosis, which would be an additional reason not to add an antiplatelet here.
    However, if he is at high risk for falling, I would be tempted to aim for a lower degree of therapeutic anticoagulation (recognizing that his not evidence-based but pathophysiology-based advice); and/or using the ACTIVE A regimen of ASA+clopidogrel instead.
    I would also not subject this patient to any further testing – the asymptomatic carotid stenosis is akin to an incidental finding in the work-up of his gait. Most gait issues are due to posterior circulation disease (vertebrobasilar) or non-ischemic disease. I certainly would not subject this asymptomatic lesion to a stent or surgery.

  7. Two coleagues cite the paper by J. Donzé et al. concluding that patients on oral anticoagulants at high risk of falls did not have a significantly increased risk of major bleeds. Unstable gait was regarded as high risk for falls. My reason says that this is improbable. If someone has the high risk of falling he or she will sooner or later fall. When one falls, one hurts or hits himself or herself and this brings about bleeding. Even major bleeding. The larger number of patients than 515 might prove the opposite. So I had to search Pubmed which showed the paper on 4093 patients (their age above or equal to 80 yrs) by Daniela Poli et al. (Bleeding risk in very old patients on vitamin K antagonist treatment: results of a prospective collaborative study on elderly patients followed by Italian Centres for Anticoagulation.) They found that „Bleeding risk was also significantly associated with history of previous bleeding events, previous falls, and cancer.“
    http://www.ncbi.nlm.nih.gov/pubmed/21810658 Circulation, 2011 Aug 16;124(7):824-9.
    Patients at risk for falling showed a risk of major bleedings approx. 5-fold higher than the other patients, in agreement with previous data (3 refs.) So one can find four papers in opposition to the one by J. Donzé. Moreoever, D.Poli has much bigger number of the patients followed. Competing-Risk Regression Analysis revealed the hazard ratio for history of bleeding, history of falls, active cancer 5.46, 3.06, 2.41, respectively.
    J. Donzé cites one statistical calculation: … a patient with atrial fibrillation taking oral anticoagulants would have to fall about 295 times a year before the risk of fall-related subdural hemorrhage… Just a week ago, a man had fallen while anticoagulated (fatal intracranial haemorhhage). It was, unfortunately, one fall in one year for the man.

  8. Dan Hackam, MD PhD says:

    I agree with this. That is why if he is falling, it might be better to use DAPT as in ACTIVE A, which specifically recruited patients who were not good candidates for oral anticoagulant therapy (and compared against aspirin, not placebo).

  9. Dan Hackam, MD PhD says:

    PS: I assume normal pressure hydrocephalus and vitamin B12 deficiency, among other nonvascular conditions, have been excluded.

  10. HOSSEIN Pourkalbasi Esfahani, MD says:

    I agree with continuing warfarin but in lower dose (INR 1/8 )
    Iignore ICA stenosis as it is asymptomatic
    MRA dose not my therapy strategy

  11. Enrique Guadiana, Cardiology says:

    1.- Continue with warfarin therapy. He has well managed stability and no complications for long time. Advice the patient how to prevent falls.
    2.- Control risk fator and medical therapy. Hi is a symptomatic.
    3.- No need for MRI.

  12. Mukundan Chelakkat, MD,DM ( cardiology) says:

    1. Definitely there is a risk of bleeding in a patient with history of unstable gait and at An age above eighty.
    I would like to change the warfarin to dabigatran or rivoroxaban as there are enough studies to support the use in non valvular AF. I would definitely add aspirin as there is significant carotid stenosis.
    2. The carotid stenosis in doppler is 95%, we have to rule out other causes of ataxia and if none of them are there we can attribute it to carotid stenosis itself. A MR Angio can help in decision making and if it is so i would consider carotid stenting for him.
    3. MR angio is definitely of use in this case as i have explained earlier.

  13. Judith Andersen, AB, MD says:

    Interesting –not a lot of activisim. That may be appropriate, but progressive CNS symptoms in a gentleman with clear-cut atheroocclusive disease and symptoms is worrisome — and suggestive of flow issues elsewhere in the cerebral vasculature. I always assume that a patient like this is my father, on a good day. I can’t see that dabigatran would be safer than warfarin, but think that rivaroxaban and aspirin might be, and that diagnostics designed to provide information about both the efficacy and safety of intervention might be useful, i.e a simple contrast-enhanced MRI to assess any other brain pathology leading to instability and likelihood of falling. Not all gait instability and fall-risk is due to cerebrovascular disease. Please take good care of my father.

  14. Judith Andersen, AB, MD says:

    An afterthought– and don’t assume that he–my father –doesn’t add value to the universe. I am not a fan of doing ridiculously agressive things to elderly folks whose medical conditions do not warrant extreme intervention. Neither am I supportive of ignoring clear-cut symptoms of cerebrovascular insufficiency. I think any of the approaches above that provide an intervention-susceptible diagnosis are reasonable. This is a functional elderly individual with clearly-defined carotid disease, who has disabling symptoms related to cerebrovascular dysfunction. I’m not sure what the wisest recommendation is, but I do not think it is to maintain the status quo.

  15. David Powell , MD, FACC says:

    A substantial proportion of nonagenarians have a gait disturbance. I would not intervene on the asymptomatic carotid stenosis. The studies showing benefit were before aggressive medical therapy; the time frame was five years, and the periprocedural stroke risk is front loaded.
    Would maintain warfarin. No clear role for DAT, as ACTIVE W actually showed an increase in bleeding on DAT among patients chronically on warfarin.
    Novel agents: maybe apixaban once approved, but only if warfarin becomes unfeasible. No aspirin.
    MRA..then a lot of patients will get one.
    Gait therapy, fall precautions, a cane, statins

  16. Jeff Dickey, MD says:

    Magnetic resonance angiogram confirmed >95% stenosis. Follow up carotid ultrasound about 6 weeks after the prednisone starts shows no change, excluding in my mind polymyalgia rheumatica related giant cell arteritis (temporal arteritis) as the cause of the carotid stenosis; however, according to MKSAP16, the carotid stenosis of GCA/TA has a fusiform morphology, not seen in this patient. At last check he has no gait instability or PMR symptoms, hasn’t fallen, and is doing well on warfarin (INR 2-3), aspirin 81 mg, prednisone taper, and omeprazole. I appreciate the ability to get help and feedback on a complex interesting patient.

  17. Dan Hackam, MD PhD says:

    Great case – as suspected, the carotid stenosis turned out to be a bit of a red herring in this patient (the gait instability had nothing to do with it). However, it did trigger the decision to start ASA which will increase his risk of bleeding and provide no incremental stroke prevention benefit over well-controlled warfarin alone (the latter also controls platelet plug formation by reducing circulating thrombin levels). I agree with a statin in this case (low dose); perhaps once the PMR has settled completely and he is off prednisone (a potential risk factor for drug-induced myopathy). There were two trials in the early 1990s showing no benefit of ASA in asymptomatic carotid stenosis, as well as two follow-up trials in the mid-to-late 2000s concurring with this in asymptomatic PAD (AAA and POPADAD). And these patients did not have the benefit of warfarin….

  18. Roberto Hoffman, MD says:

    Muy interesante caso mas guiado por experiencia que evidencia (50 años de practica) he visto caso impactant por ejemplo paciente de 50 años doble reemplazo con warfarin es golpeada por bicoleta al caer golpea con la caza en el piso hematoma subdural operada con exito (y era relativamente joven!) Asi que cuidar las caidas y personas mayores usar gorra que queda bien y protege

    Very interesting case more evidence guided experience (50 years of practice) I have seen such case impactant patient 50 years a double valve replacement with warfarin is hit while on a bicycle by falling. head hit the floor subdural hematoma operated successfully (and was relatively young! So care for elderly falls and wear a hat that looks good and protects