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Showing posts with label LAA. Show all posts

Sunday, September 24, 2017

Does the Watchman LAA closure device offer a new approach to fighting strokes?

Remember, I am just a heart patient sharing his story, plus some info gathered during my recent medical treatment. I am NOT providing medical advice. Talk with your doctor if you find anything here of interest. Cheers! 

When I first posted this, I was slated to have a Watchman left atrial appendage (LAA) closure device implanted. To prepare for this heart procedure, I had a transesophageal echocardiogram (TEE) performed last Friday. The doctors discovered my LAA had already been modified. It was surgically "obliterated." Clearly, I am no longer a candidate for a Watchman. It is impossible to insert the device into my surgically modified LAA.

I was the first person in Canada to have a leaking mitral valve repaired with the aid of a DaVinci robot. I now know my surgeon not only repaired my valve but, at the same time, he "obliterated" my LAA as well. This was done in the belief that modifying the LAA would lesson my chances of having a stroke caused by a blood clot originating in the left atrial appendage. Up to 90% of blood clots originating from the heart form in the LAA.

I was facing LAA closure to lessen my chance of suffering more transient ischemic attacks (TIAs). Over the last few years, I have suffered a lot of TIAs, also known as mini-strokes. I take Pradaxa, an anticoagulant, plus Aspirin, an anti-platelet drug. This dual drug approach has worked wonderfully at preventing serious blood clot related problems. I must compliment my doctor at the Stroke Prevention & Atherosclerosis Research Centre (SPARC) in London, Ontario, Canada.

So, if my drug therapy is working so well, why implant a Watchman, a foreign object, in my heart? Because I also suffer from cerebral micro-bleeds (MBs). These are small, bleeding areas in the brain that raise the risk of hemorrhagic stroke. A hemorrhagic brain event in the presence of an anticoagulant is fatal in many cases. For this reason, all my doctors agree: stopping my anticoagulant therapy is a reasonable goal.

After a lot of consultation among my many specialists, it was decided to put the Watchman Left Atrial Appendage closure device into my heart. A lot of risks and benefits were weighed and everyone was unanimous in approving the Watchman. Now, that route is closed. Here is an interesting link: Summing up the current data, LAA occlusion is a very promising treatment to prevent AF-related strokes due to its safety, cost-effectiveness and therapeutic success.

Discovering that my appendage has been "obliterated" raises a big question: Why am I having so many TIAs if the surgical alteration of my LAA lowered my risk? One answer: my surgical closure may not have been 100% successful. Many now believe that incomplete LAA closure can actually increase the risk of clots forming in the heart; the clots form in what remains of the LAA. And how often do surgical closures fail? Answer: In some studies the failure rate has hit 80%. The LAA has proven to be a tough beast to tame. Read: Incomplete surgical ligation of the left atrial appendage—time for a new look at an old problem.

Am I worried? Surprisingly, no. I have gone years suffering numerous TIAs and have not had a full-blown stroke. Perhaps the attempted "obliteration" of my LAA, teamed with my anticoagulant therapy, is having some beneficial affects. It is impossible to say anything for certain. It's Christmas and I'm going to go with an upbeat view.

Problems are the price you pay for progress.”—Wesley Branch Rickey


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The following is my original post, written before I learned I would have a Watchman implanted and then learned I wouldn't, and couldn't, have one implanted.



I have TIAs. TIA stands for Transient Ischemic Attack. And what, you may ask, is that? Let's just call a TIA a mini-stroke and leave it at that.

My attacks usually last less than five minutes and do not amount to much, at least not individually. But, if one has enough TIAs, the damage can be additive. I have suffered minor memory loss as a result of my numerous mini-strokes. 

Having a TIA can be frightening, and rightly so. One particular attack, called an amaurosis fugax, leaves one or both eyes blind or partially blind for a number of minutes. Although there is usually no permanent brain damage, the blindness is temporary, such an event can be a precursor to a full-blown, life-altering, stroke. I've had close to a dozen of these dramatic, visual events.

TIAs and strokes are often caused by small blood clots, formed in the heart, traveling to the brain and lodging there. These small clots can block the blood flow to the brain. With TIAs the clot is unstable and quickly disintegrates. Blood flow is soon restored. With a brain-damaging stroke, the clot does not break-up and medical attention is needed immediately to prevent permanent brain damage.

Attempting to prevent the formation of these small blood clots is the usual response to frequent TIAs. This can mean taking an anti-coagulant for life. This, of course, comes with its own host of associated risks. 

And ironically, one of the increased risks from taking anti-coagulants can be a type of stroke - a hemorrhagic stroke. A stroke resulting from bleeding in the brain: a hemorrhage.

I take Pradaxa, one of the newer anti-coagulants. Many people rely on warfarin. That's right, the chemical used in rat poison.

I am not an ideal candidate for Pradaxa, or any anticoagulant, as I have micro-bleeding in the brain. I live with threats from both types of strokes mentioned previously. 

Now, there is a new approach to fighting the blood clots that have traveled from my heart to my brain and caused my TIAs. It's a surgical solution but minimally invasive. I learned about this new method of combating TIAs, in cases such as mine, from one of my doctors at the London Health Sciences Centre.

Because I have micro-bleeding in the brain, I am not a great candidate for anti-coagulants. That's why I don't take warfarin, also known as Coumadin. Pradaxa is not as prone to causing a hemorrhagic stroke as warfarin but, that said, there is still an increased risk of bleeding. Not good. And, of the two types of stroke, hemorrhagic strokes are more often fatal and, if one survives, the lasting damage more severe.

Why do some hearts generate clots and not others? Often the answer is atrial fibrillation or AFib. Some hearts, the ones producing clots, often have a quivering, irregular heartbeat. The blood tends to pool and swirl inside the heart before being pumped out to the body. This pooling and swirling in the heart encourages the formation of blood clots.

It is now believe the clots coming from the heart are originating, for the most part, in a small sack on the left side of the heart known as the left atrial appendage (LAA). Blood gets into the small sack and remains trapped there long enough for small but dangerous clots to form. These clots eventually leave the LAA to be pumped out of the heart and to the brain where they may cause a TIA or stroke.

If this theory is right, and there appears to be good reason to believe it is, then preventing blood from collecting in the LAA appears to be a partial answer. 

Some cardiac surgeons are now plugging the LAA with a small closure device. There are a number of competing implants, among them is the Watchman from Boston Scientific Corporation.

This is what the FDA, U.S. Food and Drug Administration, has to say:

The Watchman LAA Closure Device is permanently implanted in the left atrial appendage (LAA) of the heart to prevent LAA blood clots from entering the bloodstream and potentially causing a stroke.

The cardiac-surgeon inserts the delivery catheter into the body through a vein in the leg. The catheter is threaded through the body until it reaches the right atrium of the heart. The physician makes a small hole through the wall between the two upper chambers of the heart (atrial septum) so the catheter can reach the LAA. The physician then pushes the device through the delivery catheter into the LAA where it opens up like an umbrella and is permanently implanted. Once in place, a thin layer of tissue grows over it in about 45 days.

The FDA notes that the device is used in patients who have atrial fibrillation, AFib, that is not related to heart valve disease.

Some time after the insertion of the device,  a patient may be taken off the riskiest anti-coagulants. This action should cut the patient's risk of having a hemorrhagic stroke. I believe this is the big benefit from having an LAA closure device implanted.

I understand that even with the Watchman implanted, taking low-dose Aspirin, also known by the generic name of ASA in Canada, may be necessary for the rest of the patient's life. ASA is a far less risky drug than warfarin, Pradaxa, Xarelto and the other common anti-coagulants. And it is far less costly. My Pradaxa therapy is not cheap. Taking sophisticated drugs for life can be awfully expensive.

Will I have a Watchman or similar device inserted in my LAA? I don't know. The idea has been raised and my doctors are in consultation. I would not be surprised to have this new solution to AFib caused TIAs and strokes applied in my case. The Watchman is not a perfect solution. One can still suffer a stroke from a clot originating in another part of the heart. The Watchman only stops the clots coming from the LAA.

As I have made clear, the use of anticoagulants is contraindicated in folk like me. For that reason, the Watchman looks good despite its shortcomings.

I was the first person in Canada to have a failed mitral valve repaired robotically using the da Vinci system, and I was one of the first patients to benefit from the use of the experimental T7 MRI unit at LHSC. I've had good luck with new procedures in the past.

As I learn more, I'll repost or add to this post. Cheers!

Let me end with this final video. If you have AFib but are not an ideal candidate for anticoagulants, for whatever reason, you might find the following video interesting. Talk with you cardiologist.

Remember, I am just a heart patient sharing his story. This is NOT medical advice. Cheers!