STANFORD, CA — New research reports that veterans newly diagnosed with atrial fibrillation (AF) have better outcomes when managed within the first 90 days by a cardiologist rather than a primary-care physician[1].
The adjusted risk of stroke was reduced 9% and risk of death cut 11%, with veterans cared for by a cardiologist also more likely to be hospitalized for AF/supraventricular tachycardia (SVT) and MI.
Receipt of early oral anticoagulation appeared to partially mediate the lower risk of stroke, but not death, according to the study, published in the July 4, 2017 issue of the Journal of the American College of Cardiology.
"This is hypothesis-generating, but I think really calls out the fact we need to evaluate systems of care and even do clinical trials in that area," senior author Dr Mintu Turakhia (Stanford University and VA Palo Alto Health Care System) told theheart.org|Medscape Cardiology.
"This by no means implies that primary care is doing a worse job or that every afib patient should see a cardiologist," he said. "What it means to me is that we need better ways to scale expertise in complex conditions, whether it's afib or anything else, and that's not to clone more cardiologists. The way to face this is to have better technology and tech-enabled solutions to make sure that someone who lives 300 miles away from the cardiologist and someone who lives on the Upper East Side or in San Francisco get access to the same care."
Dr Stanley Nattel (Montreal Heart Institute, QC), who was not involved with the study, agreed that it raises the possibility for future research that there's a component of better care among cardiologists. But the results should be interpreted very cautiously because of the size of the mortality and stroke differences between groups.
"There are major, major differences in outcome between the groups, and there's no intervention in the AF field that's ever been shown to approach anything that size of a difference: rhythm control, anticoagulation, beta-blockers," he said.
The most likely explanation is selection of patients with a better prognosis for care by a cardiologist, possibly driven by socioeconomic or other reasons, Nattel said.
"My concern is that inaccurate transmission of these findings might make patients inappropriately avoid family doctor care for AF and that unscrupulous corporations or individuals might exploit the findings for scaremongering and manipulative advertising," he added.
TREAT-AF Cohort
Few studies have examined the effect of treating specialty on AF outcomes, although the investigators previously reported that rates of oral anticoagulation (OAC) are higher among veterans managed by cardiologists within 90 days of an AF diagnosis in the Retrospective Evaluation and Assessment of Therapies in AF (TREAT-AF) study[2].
The present analysis compared outcomes in TREAT-AF between 69,901 patients receiving cardiology care and 114,260 receiving primary care only. Cardiology-treated patients lived closer to medical centers, were slightly younger (68.5 vs 71.6 years), but were sicker, as reflected in higher rates of baseline hypertension, diabetes, coronary disease, MI, and stroke.
Those managed by cardiologists vs primary-care physicians were also more likely within the first 90 days to be prescribed an OAC (70.3% vs 58.8%), rate-control agents (90.1% vs 80.5%), rhythm-control agents (20.8% vs 11%), antiplatelet agents (42.6% vs 28.6%), statins (65.6% vs 58.1%), and ACE inhibitors/angiotensin receptor blockers (66% vs 57.5%; P<0.0001 for all).
Cardiology care was associated with better outcomes than primary care in unadjusted and adjusted analyses.
Outcomes by Management Type*
| End point | Cardiology | Primary care | Adjusted HR (95% CI) |
|---|---|---|---|
| Ischemic stroke | 7.6 | 8.8 | 0.91 (0.86–0.96) |
| Death | 69.4 | 85.3 | 0.89 (0.88–0.91) |
| Death within 30 days of CV hospitalization | 15.5 | 18.8 | 0.88 (0.84–0.91) |
| Hospitalization for AF/SVT | 78.2 | 43.1 | 1.38 (1.35–1.42) |
| Hospitalization for MI | 57.8 | 45.7 | 1.03 (1.00–1.05) |
*Incidence per 1000 person-years, unadjusted
Mediation analyses, however, showed an indirect effect of early OAC receipt on stroke that was of borderline statistical significance.
"The way that we framed our statistical analyses was to be exceptionally conservative; we adjusted for everything and arguably could have overadjusted," said Turkahia.
He said generalizability of the results is limited by the fact that only 1.7% of patients were women, an AF population known to be at greater risk for strokes and death. That said, "What you can infer is that women also benefit from anticoagulation, we know that from the randomized trials; and they also benefit from other therapies for heart failure and coronary disease; so it stands to reason that making sure women and men get appropriate care early in the course of their disease would be important."
Although early OAC therapy was not a "a primary factor" behind the benefits observed in the study, it is still a proven stroke-prevention therapy and may be a source "of low-hanging fruit to improve outcomes," Dr William Whang (Icahn School of Medicine at Mount Sinai, NY) writes in an accompanying editorial[3].
For instance, the proportion of high-risk AF patients receiving anticoagulation therapy rose from 77% to 95% after specialist-led anticoagulation assessment was delivered in 56 UK primary-care practices[4]. Although not yet fully studied, integrated care models may also offer greater dissemination of guideline-based therapies.
In the meantime, the study provides an important statement about the critical role cardiologists play in framing the decisions that patients diagnosed with AF face, writes Whang.
"Despite the growing administrative hurdles and outside noise for us and our patients, we cannot forget that as choice architects, our efforts may make all the difference."
The study was supported by the VA, the American Heart Association, and Stanford University Department of Medicine. Turakhia reports receiving research grants from Medtronic and Janssen Pharmaceuticals and having served as a consultant/advisory board member for Medtronic, St. Jude Medical, and Abbott. Disclosures for the coauthors are listed in the paper. Nattel and Whang reported no relevant financial relationships.
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Medscape Medical News © 2017
Cite this: Study Links Early Cardiology Care to Better AF Outcomes - Medscape - Jun 28, 2017.
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