Data Evolving for Pharmacological Treatment Strategies for Patients with AF and Valvular Heart Disease

San Francisco, CA—Despite the substantial incidence of atrial fibrillation (AF) in patients with valvular heart disease, there is a lack of data in the literature regarding optimal pharmacological treatment strategies in this patient population, Ted Feldman, MD, of Evanston Hospital, said at TCT 2013.

Baseline data from the PARTNER II trial demonstrate that 30% to nearly 50% of patients who underwent valve implantation had AF, Feldman said. However, the available AF treatment database is derived from data on nonvalvular disease. Therefore, Feldman focused on current practice vs. available knowledge surrounding best treatment strategies in this population. 

According to treatment recommendations from the PARTNER II trial, patients with AF can be treated either with aspirin and an oral anticoagulant or aspirin and clopidogrel (Plavix; Bristol-Myers Squibb/Sanofi). Similarly, patients in the COAPT trial, which evaluated MitraClip (Abbott Vascular) were treated with an oral anticoagulant or aspirin and an oral anticoagulant. It was after these treatment decisions were made that important data points emerged regarding combination therapy with warfarin and antiplatelet drugs in this patient population, Feldman said.

The WOEST randomized comparison trial of dual therapy (warfarin and clopidogrel) vs. triple therapy (warfarin, aspirin and clopidogrel) included a range of patients with AF and valvular heart disease, including those with mechanical valves, AF/atrial flutter and those with a history of PCI. Findings from the trial demonstrated a bleeding incidence of 44.4% in the triple-therapy group and 19% in the dual-therapy group (HR 0.36; 95% CI 0.26-0.50; P<.0001). A take-home message from these results, according to Feldman, is that dual therapy is safer than triple therapy. The incidence of thrombotic complications was also higher with triple therapy compared with dual therapy (17.6% vs. 11.1%; HR 0.60; 95% CI 0.38-0.94; P=.025).   

data.evolve.tues.29Another challenge in the treatment of this patient population is the availability of “mix and match” considerations such as multiple oral antithrombotics and oral antiplatelet drugs. However, there are indications that combinations outside of warfarin plus aspirin or warfarin plus clopidogrel are not wise treatment choices, Feldman said, citing data from APPRAISE 2 which was stopped early due to an increased bleeding rate with dual antiplatelet therapy. A simple rule of thumb, Feldman cautioned, is to “stick with the old stuff.”

A second trial by Eikelboom and colleagues published in The New England Journal of Medicine was stopped early due to an excess of thromboembolic and bleeding events associated with dabigatran (Pradaxa, Boehringer Ingelheim) in patients with mechanical valves. One concept Feldman described as exciting and promising is the combined use of a transcatheter aortic valve and left atrial appendage closure, which could eliminate the decision over dual or triple therapy, or dual or single therapy. 

Feldman ended the presentation by citing the high number of emergency hospitalizations for bleeding complications associated with warfarin in the US (see Figure). 

“It is pretty profound, and when seen through the lens of the number of valve patients that we are already treating, it really highlights this session, and this discussion will probably grow over the next several years,” he said.


Disclosures: 

Feldman reported receiving grant support from Abbott Vascular, Boston Scientific, Edwards Lifesciences and WL Gore & Associates and consultant fees from Abbott Vascular, Boston Scientific, Coherex, Edwards Lifesciences, Intervalve, Daiichi-Sankyo/Eli Lilly and WL Gore & Associates. 

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