Chinese Patients With A-fib Are at Especially High Risk of Stopping Warfarin

Keeping Chinese patients with A-fib on oral anticoagulation is a major problem, according to a new registry study, with about four in every 10 stopping treatment within 1 year and more than half coming off by 2 years.

Certain factors—including no or partial insurance coverage, paroxysmal symptoms, and a lack of a prior history of stroke, transient ischemic attack, or thromboembolism—identified patients who were more likely to discontinue therapy, lead author Zhi-Zun Wang, MD (Beijing Anzhen Hospital, China), and colleagues report in a study published online July 5, 2016, ahead of print in Circulation: Cardiovascular Quality and Outcomes.

“Our findings can be used to identify patients who are at high risk for nonpersistence of warfarin therapy and require closer attention,” senior author Chang-Sheng Ma, MD (Beijing Anzhen Hospital), told TCTMD in an email.

Efforts need to be made to improve systemic follow-up of those patients, he added, noting that specialized A-fib clinics were set up at his center years ago with staff members who keep in touch with each patient either by phone or online. “We hope our effort will benefit every patient coming to our clinics, and eventually promote the development of atrial fibrillation management in China, which will benefit more patients,” Ma said.

‘Could Be Even Worse’

Using the Chinese Atrial Fibrillation Registry (CAFR), a prospective, multicenter study of patients treated in Beijing-area hospitals, the investigators looked at data on 1,461 patients with nonvalvular A-fib who newly initiated warfarin therapy between August 2011 and June 2014.

Within the first 3 months of follow-up, 22.1% of patients reported that they had stopped taking warfarin, although the reasons were not recorded. That figure rose to 33.6% by 6 months, 44.4% by 1 year, and 57.6% by 2 years.

The authors note that previous studies in other populations have shown that a lower percentage of patients—22% to 33%—discontinued warfarin within the first year.

“What really surprised us was that the situation could be more challenging than we expected,,” Ma said, pointing to the fact that patients mostly came from the Beijing area and likely had higher socioeconomic status and better insurance coverage compared with patients in other parts of China.

“In addition, participating hospitals in this study, mostly tertiary hospitals, may represent the institutes with more resources and expertise than county-level or even more grassroots-level hospitals,” he said. “In other words, the situation in the general population nationwide in China could be even worse.”

Compounding the issue of failing to continue on warfarin after starting it is the low rate of initial prescription. A prior study showed that only 6.75% of Chinese patients with A-fib received warfarin.

Ma attributed that to a lack of understanding of the stroke risk associated with A-fib among patients and clinicians and an overestimation of the bleeding risk, which makes clinicians reluctant to prescribe oral anticoagulation. Also, the regular monitoring required with warfarin is inconvenient, particularly in rural areas. “This could be a serious problem contributing to the underuse of warfarin in China,” Ma said. “Thus, we still have a long way to go until we get better management of atrial fibrillation in Chinese patients.”

Surveillance Is Key

Commenting on the study for TCTMD, Sumeet Chugh, MD (Cedars-Sinai Medical Center, Los Angeles, CA), said the problem with getting patients to start taking oral anticoagulation and stick with it is not unique to China and can be found in countries around the world.

There is interest, he said, in comparing the situation among different regions because most studies have been conducted in high-income countries in North America and Europe.

So, Chugh noted, studies like that by Wang et al—though yielding expected results—are important first steps toward improving patient care in different regions. “We’ve got a lot of work to do in terms of global health and these are the kinds of efforts that make . . . headway into reducing the global burden of atrial fibrillation,” he said, stressing the need for greater surveillance.

“What is the biggest impact on public health? It comes from simple but important things like increasing awareness, increasing education about prevention,” Chugh said. “We can’t pull that out of thin air. We have to have regional surveillance because you can’t paint the entire world—obviously—with one broad brush. So you have to have regional surveillance that guides public health implementation.”

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