Whiteboard Animation Video



You are reviewing your patient’s chart and you notice that they are on dual antiplatelet therapy aka DAPT. You think: Why is my patient on these two meds? Should I keep them on both the aspirin and the P2Y12 inhibitor? This whiteboard animation will shed some light…


First, when you ask yourself, “why is my patient on DAPT?” There are two big guideline-based indications

(1) your patient had acute coronary syndrome event

OR (2) your patient had a  stent placed in the cath lab for either ACS or stable angina

Now, you may be thinking, there is no way it is that clear-cut.  And you are sort of right

The third group of patients on DAPT just because they have a (3) high atherosclerotic burden. Think of your patient with peripheral artery disease or prior stroke or multiple coronary events


So, you figured out why your patient is on DAPT to begin with. Now, why are they on Clopidogrel and not Prasugrel or Ticagrelor? What is the difference anyway?

Aren’t they all P2Y12 inhibitors?  


Think potency versus bleeding risk.  Prasugrel and Ticagrelor are more potent meaning they are better at preventing ischemic events. But, that also means they have higher bleeding risks. Prasugrel and ticagrelor are faster acting so may be used more acutely during an ACS event. But  often times, it comes down to cost. Prasugrel is the most expensive and clopidogrel is the least.


Ok, so you have a clear idea of why your patient may be on  DAPT that specific P2Y12 inhibitor. How long should they stay on DAPT anyways? 

It all depends on the indication for DAPT. If your patient was started on DAPT post-stent for stable ischemic disease,  we tend to keep them  on DAPT for 6 months. 

If your patient had ACS event (with or without a stent placement), we tend to keep them  on DAPT for 12 months.  The reason why its longer is that ACS have much higher thrombotic risk.

Two Caveats:

  1. We titrate how many months we keep patients on DAPT depending on the patient’s bleeding and ischemic risk. 
  2. The duration of DAPT is moving target since the latest guidelines haven’t caught up to the latest trials establishing safety of stopping DAPT as early as 3-6 months or even as early as after 1 month (STOPDAPT2 Trial)


It is finally time to transition from DAPT to monotherapy. Should I stop aspirin or the P2Y12 inhibitor? Truth is, there are no guideline recommendations. 

But what is surprising to many is that despite aspirin being often called “baby aspirin,” aspirin actually has a higher risk. The reason is both aspirin and P2Y12 inhibits block platelets but because aspirin is also a COX inhibitor, it blocks prostaglandin production and so the gastric mucosa loses some protection so aspirin has been associated with higher bleeding risks compared to P2Y12 inhibitors.

So at the end of day, no matter which you choose to stop, you technically can’t be wrong. But it may be safer to stop aspirin


Just when you thought you could handle any case in walks a patient on aspirin, prasugrel, AND rivaroxaban.Now what?

So aspirin and prasugrel are both antiplatelet agents and things like rivaroxaban, apixaban, enoxaparin, warfarin are anticoagulant, usually for afib, DVT or PEs. You may be hesitant to stop the triple therapy, but triple therapy does significantly increase your bleeding risk so long-term its best to keep the the anticoagulant for the afib or PE history and drop to one antiplatelet.


So do you drop the aspirin or a P2Y12 inhibitor? 

The only regimen that’s been tested is dropping the aspirin and continuing the P2Y12. And the P2Y12 that’s been tested is clopidogrel so that is often what is seen in practice. How long do I keep both anticoagulant and antiplatelet therapy?
As a throwback to earlier, for ACS, as a general rule of thumb, it is  12 months, For a stent for stable ischemic disease, duration is  six months.

In both cases, monotherapy is with the anticoagulant alone. 


Let’s recap: 

  1. First, identify the indication for DAPT: either your patient suffered an ACS event or had a stent placed for ischemic stable disease. Next, identify which P2Y12 inhibitor they are on, recalling that ticagrelor and prasugrel are more potent and have a higher bleeding risk, but that ultimately often it comes down to cost and clopidogrel, being more affordable, is often the P2Y12i used. Then think about the duration of DAPT. Patients with ACS as indication should remain on DAPT for 12 months, while those with stable ischemic disease require DAPT for 6 months. 
  2. Once it is time to transition from DAPT to monotherapy, while there are no guideline based recommendations, often dropping aspirin and keeping the P2Y12i is safer. 
  3. Lastly, if your patient also needs to be on an anticoagulant, triple therapy should be avoided and dual therapy with the anticoagulant and an antiplatelet agent should be maintained for the same duration as DAPT. Once transition to monotherapy is made, the monotherapy should be with the anticoagulant for both indications. 


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