Clinical Trials Results: Watchman Better Than a Lifetime on Warfarin

by Steve S. Ryan, PHD, October 2015, Updated January 26, 2016

According to recent studies, you are better off having a Watchman device installed than spending a lifetime on warfarin.

WATCHMAN device for Left Atrial Appendage Closure

In two randomized clinical trials comparing Left Atrial Appendage Closure (LACC-Watchman Device) to warfarin, 1,261 patients from the PROTECT AF and PREVAIL trials were studied. The follow-up period was around 3.3 years. Patients receiving the Watchman compared to patients on warfarin had significantly fewer:

• Hemorrhagic strokes
• Cardiovascular/unexplained death
• Non-procedural bleeding
• All-cause stroke or systemic embolism was similar between both strategies.

There were more ischemic strokes in the Watchman device group, but this was balanced by a greater number of hemorrhagic strokes in the Warfarin group.

Warfarin (Coumadin) various dosages

However, the patients in the control group of the PREVIAL trial were considered “unusual” in that, given their risk profile, they had a much lower ischemic stroke rate than ever observed in any clinical trial. See Getting FDA Approval for the Watchman Device.

(The U.S. Food and Drug Administration (FDA) approved Boston Scientific’s WATCHMAN™ LAA closure technology for use in the U.S. on March 13, 2015. It has been available internationally since 2009. The FDA approval of the WATCHMAN device is based on the clinical program which consists of numerous studies, with more than 2,400 patients and nearly 6,000 patient-years of follow-up.) 

What Patients Need to Know: Watchman Actually Better Than Warfarin

The Watchman device provides similar protection against having an A-Fib (ischemic) stroke as being on warfarin.

But the Watchman device isn’t simply an “alternative” to warfarin, but rather an improvement or advance or progression. One would intuitively expect that people receiving the Watchman device would also have less hemorrhagic strokes and bleeding compared to those on warfarin, which these studies do demonstrate.

Welcome Alternative to a Lifetime on Warfarin

Warfarin and other anticoagulants work by causing bleeding and are inherently dangerous. The Watchman device is not only a welcome alternative to a lifetime on warfarin, but is actually better than warfarin.

Among other bad side effects, long-term use of anticoagulants such as warfarin have been known to not only cause hemorrhagic strokes but also microbleeds in the brain which lead to dementia. See Patient on Anticoagulation Therapy for 10 Years Develops Microbleeds and Dementia.

A 2015 study found evidence of microbleeds in 99% of subjects aged 65 or older, and that increasing the imaging strength increased the number of detectable microbleeds. Microbleeds have been suggested to be predictive of hemorrhagic stroke.

According to current research, you are better off having a Watchman device installed than spending a lifetime on warfarin. (Of course, this assumes that the doctor performing the procedure is beyond his/her learning curve. That is, when operating doctors are first performing the procedure, there is a higher risk for procedural complications.)

What About the New Anticoagulants (NOACs)?

Does this research apply to the new anticoagulants like Pradaxa, Xarelto, Eliquis and Savaysa/Lixiana? Technically no. This research only applies to warfarin. But intuitively one would expect the same general principles to apply. All anticoagulants cause bleeding. That’s how they work.

Caveat—Long-Term Effects of Watchman?

What are the long-term effects of leaving a mechanical device like the Watchman inside the heart? We know that, after a few months, heart tissue grows over most of the Watchman device so that the LAA is permanently closed off from the rest of the heart.

It seems unlikely that complications would develop after a long period of time as has happened with warfarin. But we can’t say that for sure until enough time has passed. The first clinical trial installation of the Watchman device in the US was in 2009 and in Europe in 2004. So far no long-term complications have developed.

CT Brain scan showing Ischemic Stroke

Preventing Stroke in the Elderly—Even If They Don’t Have A-Fib!

One of the great potentials of the Watchman device is that it may someday be used to prevent stroke in the elderly even if they don’t have A-Fib. Imagine a world where you no longer live in fear of a stroke as you get older, where 90%-95% of stroke risk can be eliminated by a simple 20 minute procedure. The Watchman device (and other Left Atrium Occlusion Devices such as the Lariat and the surgical AtriClip) may change the way elderly medicine is practiced.

How many people turning 70 or 75 would welcome a device that would almost guarantee freedom from the most severe type of ischemic stroke (a cardioembolic stroke)? The Watchman device has the potential to greatly reduce or eliminate the threat of strokes in the elderly!