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Pharmacogenomics may play an important role in treatment and more specifically prevention of stroke in the future. The way that I see that this playing a role is helping us pick the best medication choices for each patient. And I see this in a few different areas. One, if we give people blood thinners, it seems that there are some people that respond better to aspirin than others. Some people respond better to clopidogrel than others. And the same thing goes with aspirin and extended release dipyridamole. We also see this with blood pressure medications that some people just respond to certain types of blood pressure medications better and so with pharmacogenomics would, I could envision down the line is being able to assess what medications you're going to respond to best by what your genetics say. You won't be able to recognize that certain genetic or certain gene types, genetic profiles make you a better candidate for this type of medication and these types of medications. And so we can say, look, you know, for you specifically your body, your genes, you do better on aspirin and hydrochlorothiazide. And this person does better on these medications. And I do think that's coming down the line at some point.
Pharmacogenomics may play an important role in treatment and more specifically prevention of stroke in the future. The way that I see that this playing a role is helping us pick the best medication choices for each patient. And I see this in a few different areas. One, if we give people blood thinners, it seems that there are some people that respond better to aspirin than others. Some people respond better to clopidogrel than others. And the same thing goes with aspirin and extended release dipyridamole. We also see this with blood pressure medications that some people just respond to certain types of blood pressure medications better and so with pharmacogenomics would, I could envision down the line is being able to assess what medications you're going to respond to best by what your genetics say. You won't be able to recognize that certain genetic or certain gene types, genetic profiles make you a better candidate for this type of medication and these types of medications. And so we can say, look, you know, for you specifically your body, your genes, you do better on aspirin and hydrochlorothiazide. And this person does better on these medications. And I do think that's coming down the line at some point.
As we move up, so then if we're looking at other types of strokes beyond a fib and carotid stenosis, generally the approach is a multi sort of pronged approach. One, it's some type of blood thinner. The mainstay, the one that we use the longest is aspirin. Often a question that's asked is, well what's the right dose of Aspirin? We don't know. Somewhere between 81 and 325 and it sort of depends on the case. I would point out in someone using an 81 milligram aspirin, I would advise not using an enteric coated, not using an enteric coated aspirin as it may be less bioavailable. But between 81 and 325, any dose probably works and it sort of depends on the patient and something to talk to your doctor about. There are other types of blood thinners and someone who comes in and it was on aspirin already, we'll consider other types of blood thinners that may be more effective than aspirin. One's called clopidigrel or Plavix is the brand name, but it's available as a generic and another one that's extended release diaprimonal and aspirin together and that's got a brand name called agronox. Both of those drugs can be more effective than aspirin at preventing stroke in the right patient. The next thing we want to pay attention to is the cholesterol. And again, I emphasize there is lots of data now that's out that shows that statins help prevent recurrent strokes and we pay very close attention to what the total cholesterol is and also what that LDL, the bad cholesterol is. And we want that LDL low. Less than a hundred and in some cases less than 70. Next we wouldn't pay careful attention to the blood pressure. And from my perspective, blood pressure control in the first few days after a stroke is not crucial. We actually let the blood pressure go up a little bit in the first few days with the idea being there's a clot up there and the body knows how to get blood around that clot and it does it by elevated blood pressure. But over the long term, months for sure, we want that blood pressure well controlled. And that's often a combination of diet, watching your sodium intake, exercise, and medications. Again, I point out that the disturbing sort of a statistic from the American Heart Association that with high blood pressure, 50% of patients aren't well controlled and is the major risk factor for stroke in a crucial one for us to control well.
With A-fib, there are four major drugs that we can choose as far as prevention. These are very effective drugs, clearly better than things like aspirin. These are strong blood thinners. The four drugs are warfarin or coumadin. This is the drug that's been around the longest and we have the most experience with it. The drawback to Warfarin is that it does tend to cause more drug interactions and evolves blood tests on somewhat of a regular basis and careful attention to the diet. There are three newer medications that have just come in the market in the last few years. A drug called Pradaxa, and another called Eliquis and lastly Zeralto. These are drugs that had the distinct advantage of not requiring blood tests, of having minimal drug interactions. The major drawback to them is that there are no blood tests, and so that can make it a challenge if the drug has to be reversed for any reason.
For treatment of an acute stroke, a stroke that has just happened, there is one drug that's been FDA approved called TPA or tissue plasminogen activator. That's a drug that right now it can only be given in the hospital and this is the reason that we want people to get into the hospital fast. On top of that, it can only be given really within the first four and a half hours after stroke onset, I would back up and point out that it's been FDA approved to three hours, but most hospitals recognize an advisory from the American Heart and Stroke Association that have recommended that we give it up to four and a half hours in very select patients. And so because of this, it's critical to get into the hospital. It's also critical. This is a clot buster and breaks up blood clots. And so the reason we want people in the hospital before we give the medication is we want to first establish one that that person hasn't had a hemorrhage cause it actually, it's interesting the signs and symptoms of a hemorrhage versus an ischemic stroke can be identical. If someone's got a clot that's blocking an artery, an artery that rupture, you cannot tell the difference looking at someone generally. So the way that we differentiate is by a cat scan. So having someone come in the hospital and get a cat scan is a big part of what we need before we give them clot buster then, then we give them clot buster, recognize that this is the major drug that's approved by the FDA for treatment of stroke. But it's unfortunately far from perfect. It improves outcome, and by outcome, I mean disability by approximately 30% at three months. Now keep in mind that's all comers. And what we've seen is that people who present earlier and get treated earlier do better than people treated, you know, so someone at our one after onset does better than someone treated hour to an our three than our four. So this is such an important message to get. The earliest you can recognize the stroke symptoms and get someone into the hospital, the absolute better.
If someone comes in at between three and four and half hours, I would generally expect that the hospital's going to be a little bit more cautious. And the big issue that we worry about with TPA is the risk of bleeding. And we know that essentially the longer we wait after a stroke, the more leaky the blood vessels in the brain can get where the injuries occurred. And so the more careful we have to be about who giving tpa to, uh, so the question comes up then in someone at three to four and a half hours, we'll give tpa. In the cases that we can't give tpa to or beyond, sometimes we'll be willing to consider something called intraarterial treatment or IA TPA or IA treatment. And with this type of treatment, what ends up happening, and this is kind of like when you get with cardiology, a catheter is inserted into the artery in the leg, and a catheter can be brought up all the way into the brain to where the cloud is actually at. And then there are a few different approaches to actually trying to remove that clot. One is with something called the penumbra device where you actually have a little section and a catheter and you actually try to poke the clot, break up the clot and suck it out. Another way to do it something with something called a stent Trevor, where you actually can put the wire through the clot and open up a stent that grabs the clot and then we can pull it out. Or another option is a direct admission of tpa right at the spot where the clots at hoping to break it up. And so generally that's been felt to be more of an experimental procedure rather than something that's been proven by randomized controlled data. I would point out that just recently, earlier this month, the first randomized controlled study has come out demonstrating that actually in some cases intraarterial treatment can actually improve outcomes. Lastly, I would point out that with intraarterial treatment, there are certain cases where we know the IV clot-buster, the IV tpa is less effective. This is in cases where there's a really large clot in the brain. In some of those cases, and we have to be selective and careful. We can actually use intraarterial treatment to try to break up those clots as well. Those are the main treatments. That is the only real treatment in the acute phase of a stroke.
So in summary, treatment for acute stroke, intravenous TPA and club buster, there is something called intraarterial treatment that can be given to a certain subset of patients that most stroke centers here in Tucson are able to provide. If we look at causes of stroke and prevention for those, it's a strong anticoagulant for A fib, coumadin, Xarelto, Eliquis or Pradaxa. And then for the rest of stroke, we're looking at aspirin, Plavix, or Agoronox, cholesterol control, and blood pressure control. For a certain subset of patients with carotid artery stenosis, some of them can be aggressively treated medically, but some of them will need some type of definitive treatment to open up that narrowing. And that's either carotid endarterectomy with a vascular surgeon or carotid stenting.
As we move up from the heart, we move up into the carotid arteries and we think about carotid stenosis. And this is something that can be treated medically with aggressive risk factor control, blood pressure, cholesterol and milder blood thinners than what we just talked about, something called Plavix typically or aspirin. And we use aggressive medical therapy if the degree of narrowing is 70% or less. If the degree of narrowing in that carotid artery is more than 70% then often what we'll choose is to have surgery. And the type of surgery that's done is something called a carotid endarterectomy and this is where the artery is actually opened up by a vascular surgeon and cleaned out and then sewn back up. And that can be very effective at stroke prevention. Although in someone who's had a stroke or TIA, we tend to want to do it as early as we can safely do it after the event. There is another option in patients who are at higher risk for surgery and that's something called a carotid artery stent. And the stent is where, again, where they put the catheter up, the artery up into the carotid artery, and, and just like in the heart, deploy a stent that opens up the artery to allow blood flow to come through. So either of those things can be done, although more commonly here in Tucson, it's carotid endarterectomy surgery.
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