Transcript

Lee Tetreault:

Welcome to frequently asked questions from the session, "Current approaches to stroke prevention in atrial fibrillation." We're joined by Dr. Piazza. Before we begin with these questions, Doctor, would you be able to reiterate a few key pointers in today's session to our audience?

Dr. Piazza:  

Absolutely, and thanks for having me. First of all, it's important to recognize that one of the major comorbidities and consequences of atrial fibrillation is ischemic stroke. And as the population ages, these strokes are going to become more common but they're preventable. We have guidelines and excellent anti-thrombotic therapies to prevent stroke. Unfortunately, these therapies are under-utilized in the US and worldwide, but there are tools that we can use to implement better practices for prevention of stroke and atrial fibrillation, that focus more on the use of direct oral anticoagulants, and providing education to clinicians and patients.

Lee Tetreault:

Great. How do you select an anticoagulant for stroke prevention in atrial fibrillation?

Dr. Piazza:  

It's a really important question, and the way I start off is involving the patient and understanding what their preferences may be, and their reservations about starting an anti-thrombotic therapy. For me, it's really important that they understand the differences between warfarin and the direct oral anticoagulants. If they're older patients or they've had a family member who's taken warfarin for a long time, they might naturally gravitate towards that and they may not know a lot about these more recent anti-thrombotic therapies that are safer, and provide a very high level of stroke prevention. So I try to find out what they know, and I try to inform them based on what the recommendations are and how the different anti-thrombotic therapies have performed. Then I look at things like medication adherence, if I have a patient who I think will forget to take doses of anti-thrombotic therapy, or who needs a more rigorous environment surrounding their anticoagulation, an anti-coagulation management service can be very helpful. It doesn't mean they have to be on warfarin.

Oftentimes, anti-coagulation management services focus on warfarin, but many focus on the direct oral anticoagulants as well. And then I look for patient preferences about the frequency during the day of dosing and any other concerns that they may have about particular agents that they saw on TV or that they read about.

Lee Tetreault:

How do you use CHADS-VASc scores and HAS-BLED scores in clinical practice?

Dr. Piazza:  

That's another really important question. CHADS-VASc scores and HAS-BLED scores were developed initially for the evaluation of patients who're being considered for research studies and has also been applied to clinical practice. The CHADS-VASc score is a system that looks at a number of risk factors for stroke and you tally up the score, and if the patient is at increased risk of a stroke, that identifies someone who should be started on anti-thrombotic therapy. The HAS-BLED score is a different scoring system, this focuses on risk factors for bleeding, and is used to identify patients at a higher risk for bleeding on anti-coagulation. What's interesting is the guidelines don't advocate using the HAS-BLED score to decide which patients should not receive antithrombotic therapy. Rather, they advocate that we use the HAS-BLED score to identify individual risk factors that increase the risk of bleeding that we can modify.

So for example, one of the factors in the HAS-BLED score has to do with hypertension. If you have a patient with hypertension, we know that that increases the risk of bleeding on anti-coagulation. You'll wanna control the hypertension. Labile INRs is another factor that's considered in HAS-BLED, and maybe if your patient has that, you would wanna consider a direct oral anticoagulant that gives you more consistent antithrombotic levels. And so that's how we're really supposed to use HAS-BLED. CHADS-VASc tells you who should get anti-thrombotic therapy and HAS-BLED tells you what factors in the patient you should modify to make anti-coagulation safe.

Lee Tetreault:

Do you have a preferred DOAC?

Dr. Piazza:  

That is a really frequent question that I get, and I actually don't have one single preferred DOAC. What I try to do is understand the differences between the individual DOACs and match them to a particular patient and their preferences. So some patients may be resistant to taking a medication twice daily, and then I'll use a once-daily DOAC. If they're used to taking medications twice daily and they just wanna stick to that routine, they have their pillbox laid out, and they know what they're taking in the morning and what they're taking in the evening, then a twice-daily DOAC should be just fine. I also try to match the DOAC with their side effects and patients underlying comorbid illnesses. So patients with migraines who have a tendency towards frequent headaches, I might steer away from rivaroxaban because that is associated with an increase in frequency of headaches, and some patients will need to stop the medication because of headaches.

In other patients, there might be gastrointestinal issues that make them less tolerant of something like dabigatran which has an acidic coating to help its absorption, but can cause dispepsia or stomach pain. And so I really try to match side effects with the patient. Other reasons to pick a particular DOAC would have to do with patients frailty and perhaps body mass index. There's some studies that suggest in patients that have real morbid obesity, you may want to actually stick with warfarin where you have a better certainty that you're providing anti-coagulation at the right level and also patients who've had gastric bypass may have difficulty absorbing DOACs.

Lee Tetreault:

How do you handle stroke prevention in AF patients with frailty?

Dr. Piazza:  

That's a very common issue that I see in my clinical practice. I get a lot of referrals from our geriatrics team about this and I think the most important thing first is to focus in on that HAS-BLED score. You're not really using that HAS-BLED score to tell the primary care provider that the patient shouldn't be on anti-coagulation. You actually wanna use it to see all of the different things about the patient that you can mitigate to make anti-thrombotic therapy safe. So then I start with the HAS-BLED score, and then I talk to the patient and try to find out what their patterns for taking medications are. Are they very adherent to taking medications, or have they had difficulties remembering doses? If they have problems with adherents, then an anti-coagulation management service can really be helpful for frail patients in making sure they don't take too much anti-thrombotic therapy, but they're also not missing doses.

Many of the direct oral anticoagulants provide you with instructions on adjustments in the dose, if the patient has some of the comorbidities that go on with frailty, such as low body weight, or kidney dysfunction, or really advanced age. And so you can use those criteria to dose-reduce, but you should do that when it's truly indicated. One of the main problems we're seeing now with the direct oral anticoagulants is that providers being afraid of bleeding will dose-reduce the DOAC when the patient doesn't meet criteria for that. And you don't wanna do that, because then you don't get the efficacy for stroke prevention, and you still get some risk of bleeding.

Lee Tetreault:

This is great information, Doctor. Thank you so much for your time.

Dr. Piazza:  

My pleasure.




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