Stroke Prevention in AF: What are Your Options?

April 10, 2018

The path to reducing risk of stroke in AF patients is far from straight and narrow. A case and 3 questions test your clinical navigation skills.

Based on the 2014 ACC/AHA/HRS guidelines,1 all patients with atrial fibrillation (AF) should be stratified for risk of thrombosis and bleeding before the decision is made to initiate oral anticoagulation (OAC). The recommendation is that OAC should be started for any patient with a CHA2DS2-Vasc score ≥ 2. But, for reasons those of us in clinical practice know all too well, this doesn’t always happen. And, even in those patients who do get started on OAC, the long-term compliance (given that this is essentially “lifelong” therapy) is variable.

Case: Mrs Russell is a 74-year-old female with type 2 diabetes and hypertension who presented with paroxysmal atrial fibrillation during a recent influenza infection. She is active but lives on her own in a retirement community and does not drive. Today, she is in normal sinus rhythm at 78 beats/min and her blood pressure is 128/74 mm Hg.  Her CHA2DS2-Vasc score is 3 (1 point each for female, HTN, DM). You counsel her on her indication for anticoagulation therapy and discuss the pros and cons of warfarin and the direct oral anticoagulants (DOACs). After a long discussion, where she tells you that she cannot afford DOACs, you decide to start warfarin, even though you realize it will be difficult for her to get to regular INR checks.

Question 1. Of those patients with newly-diagnosed AF who are eligible for and prescribed OAC, what percentage of patients stop taking VKA and what percentage stop taking DOACs at 2 years in real-world practice?A. ~50% of those on VKA; ~50% of those on DOAC

B. ~30% of those on VKA; ~30% of those on DOAC

C. ~50% of those on VKA; ~30% of those on DOAC

D. ~30% of those on VKA; ~50% of those on DOAC

Please click below for answer and next question.

Answer: C. ~50% of those on VKA; ~30% of those on DOAC (stop taking the medication).

These data are reported in a “real-world” study of 27, 514 OAC-naïve patients (mean age 74, 45.7% female, follow-up ~2 years) with new onset AF from the UK Primary Care Database.2 The adherence to DOAC is higher than that to VKA but the rates of discontinuation continue to be unacceptably high. Despite the number of possible DOACs to choose from, anticoagulation adherence remains an ongoing challenge.

Case: You see Mrs Russell in the office in follow-up 1 year after her initial AF diagnosis and realize that she isn’t regular with her INR checks and only had 2 INRs out of the last 9 months that were within the appropriate range of 2-3.

Question 2. Which of the following are appropriate and approved indications for the Watchman (left atrial appendage occlusion) device?A. Patient is high risk for bleeding or has had recurrent bleeding episodes.

B. Patient struggles with compliance.

C. Patient leads an active lifestyle that places him/her at increased risk for trauma.

D. None of the above are appropriate indications

E. All of the above are appropriate indications

Please click below for answer and next question.

Answer: E. All of the above are appropriate patient situations in which to consider the Watchman LAA occlusion device as an alternative to OAC.

The Watchman device is currently the only FDA-approved device indicated for reduction of stroke risk in patients with nonvalvular AF who need an alternative to the long-term use of OAC. The 3 patients described above are all at risk for non-adherence to OAC which imposes a significant risk of stroke and systemic embolism. Ninety-two percent of Watchman patients are able to discontinue warfarin after 45 days and 99% are able to discontinue it within 1 year.3

Case: You decide Mrs Russell is a good candidate for Watchman therapy and decide to refer her for placement of a device.

Question 3. Which of the following is NOT one of the eligibility requirements for LAA occlusion therapy with the Watchman device?A. CHADS2 score >2 or CHA2DS2-Vasc score > 3.

B. Formal shared decision making (SDM) with an independent non-interventional physician.

C. Suitability for short-term warfarin/anticoagulation.

D. Left atrial appendage anatomy that is suitable for Watchman placement.

E. None of the above (all of the above are eligibility requirements for Watchman placement).

Please click below for answer and next question.

Answer: E. All of the above are eligibility requirements for Watchman placement and necessary components of getting the therapy reimbursed by Medicare and private payors.

Formal shared decision making with an independent non-interventional physician using an evidence-based decision tool (CHA2DS2-Vasc score, HAS-BLED score) on OAC in patients with nonvalvular AF prior to LAA occlusion/closure therapy is an FDA requirement and also required for insurance reimbursement. This interaction must be documented. A patient must be able to tolerate short-term warfarin but be deemed unsuitable for long term OAC (as following the implant procedure, warfarin is necessary for the short term). And, the atrial appendage anatomy must be suitable for placement of the device. LAA anatomies that are long and tall (ie, windsock, chicken wing appendage) are suitable for the device implant while shallow and wide anatomies (ie, cauliflower appendage) are not.

References:

1. January CT, Wann LS, Alpert JS, et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society.  Circulation. 2014;130:e199-e267

2. Martinez C, Katholing A, Wallenhorst C, Freedman SB. Therapy persistence in newly diagnosed non-valvular atrial fibrillation treated with warfarin or NOAC. A cohort study. Thromb Haemost. 2016;115:31-9. doi: 10.1160/TH15-04-0350. Epub 2015 Aug 6.

3. Holmes DR Jr, Kar S, Price MJ, et al. Prospective randomized evaluation of the Watchman Left Atrial Appendage Closure device in patients with atrial fibrillation versus long-term warfarin therapy: the PREVAIL trial. J Am Coll Cardiol. 2014;64:1-12. doi: 10.1016/j.jacc.2014.04.029.