Patients with ‘Valvular Atrial Fibrillation’ are often restricted from most A-Fib clinical studies and research. In particular, for NOAC trials, people with Valvular A-Fib have generally been excluded because they may have a higher rate of forming clots (e.g.: left atrial clots).
“Valvular Atrial Fibrillation” refers to those A-Fib patients with artificial heart valves or mitral stenosis.
Like most A-Fib patients, Valvular A-Fib patients with bioprosthetic or mechanical valves have to be on an anticoagulant which up to now was restricted to warfarin. So, are the new NOACs an option?
Bioprosthetic valves are non-synthetic (usually porcine) devices used to replace a defective heart valve. Compared to mechanical valves, bioprosthetic valves are less likely to cause clots, but are more prone to structural degeneration (35% fail within 15 years).
Warfarin vs Edoxaban (NOAC)
A 2017 study showed that the Novel Oral Anticoagulant (NOAC) edoxaban (brand name: Savaysa) was safer than warfarin in preventing an A-Fib stroke in people with bioprosthetic heart valves.
Edoxaban works by inhibiting factor Xa in the coagulation process. The lower dose (30 mg) was associated with a reduced rate of major bleeding, but not the higher dose (60 mg).
Compared to warfarin, edoxaban was associated with lower annual stroke rates, systemic embolic events, major bleeds, and deaths annually.
“Our analysis suggests that edoxaban appears to be a reasonable alternative to warfarin in patients with Afib and remote bioprosthetic valve implantation,” according to Dr. Robert P. Giugliano of Brigham and Women’s Hospital in Boston, MA.
Edoxaban Works With Bioprosthetic Valves But Not Mechanical Ones
For the first time, research indicates that a NOAC (edoxaban) can be used for Valvular A-Fib to prevent an A-Fib stroke―but only in the case of bioprosthetic (porcine) valves.
The NOAC, Edoxaban (Savaysa), was safer than warfarin for A-Fib patients with bioprosthetic valves.
With regards to mechanical valves, the authors cited a study in which dabigatran (Pradaxa) fared poorly in mechanical valves.
What About Other Factor Xa NOACs?
What about the other ‘factor Xa inhibitors’ such as Xarelto and Eliquis? Can they be used like edoxaban? Currently there is little clinical data on this subject. But since all three are factor Xa inhibitors, most likely they will be proven to be effective in A-Fib patients with bioprosthetic valves.
What Patients Need to Know
Do you have Valvular A-Fib and a bioprosthetic valve? Are you on warfarin? If being on warfarin is difficult for you, you now have a choice of anticoagulant. Ask your doctor about switching to the NOAC, edoxaban.
FDA approved in January 2015, the anti-clotting drug edoxaban (brand names Savaysa and Lixiana) is the fourth novel anticoagulant (NOAC) developed as an alternative to the blood thinner warfarin (Coumadin). The others are apixaban (Eliquis), dabigatran (Pradaxa) and rivaroxaban (Xarelto).
Because edoxaban is so new, we don’t have much ‘real world’ data and can only look at the data from the clinical trial. Edoxaban is available by prescription in two dosages: 60 mg once daily and 30 mg once daily.
Prevention of stroke: The higher dose of edoxaban (60 mg once daily) was as good as and tended to be better than warfarin in preventing stroke. But the lower dose (30 mg once daily) wasn’t as effective as warfarin.
Stomach bleeding: All anticoagulants cause bleeding. That’s how they work. With the higher dose of edoxaban, bleeding from the stomach was greater than with warfarin. But with the lower dose of edoxaban, bleeding was lower than with warfarin.
Kidney clearance: Edoxaban is 35% cleared by the kidneys (as compared to 25% for apixaban [Eliquis] and 80% for dabigatran [Pradaxa]). This means if your kidneys are working well (creatine clearance greater than 95ml/min), you probably shouldn’t be taking edoxaban, because your kidneys are taking it out of your body too quickly. This puts you at greater a risk of stroke than those patients taking warfarin.
No Head-To-Head Clinical Tests
Unfortunately, there haven’t been any head-to-head clinical tests comparing edoxaban with the other novel anticoagulants (NOACs). In fact, drug manufacturers have only tested their products against the standard treatment of warfarin (Coumadin).
Safety Data for Edoxaban
Edoxaban is so new we don’t have a real-world safety score yet. But in the clinical trial, stomach bleeding was greater with the higher dose than warfarin. (The lower dose edoxaban is irrelevant because it didn’t work as well as warfarin.)
The Bottom Line for Edoxaban
The limited data about edoxaban in unimpressive. As you know, I’m not a medical doctor. So if you are seeking an alternative to warfarin, talk to your doctor. If I were you, I’d skip edoxaban for now and consider apixaban (Eliquis) instead.
To date, Eliquis is the only novel anticoagulant (NOAC) that can claim that survival improved with its use compared to warfarin. Eliquis was unique in that bleeding from other sites including the stomach, bowels, and bladder was less. Eliquis earned the best safety score from the FDA Adverse Event Reporting System compared to Pradaxa, Xarelto and warfarin. For more, see Warfarin vs. Pradaxa and the Other New Anticoagulants.