SAFETY: Boosted Home Care Cuts Hospitalization in Chronic AF

Marlene Busko

December 01, 2014

CHICAGO, IL — In a 2-year Australian study, older, hospitalized patients chronic nonvalvular atrial fibrillation (AF) but no heart failure who were discharged and received a nurse-led, home-based intervention (SAFETY) spent "strikingly" fewer unplanned days back in the hospital[1]. However, even without as many unplanned hospitalizations, the patients who received the intervention did not have better event-free survival.

Prof Simon Stewart (Australian Catholic University, Melbourne) presented these findings in a late-breaking session November 17, 2014 at the American Heart Association (AHA) 2014 Scientific Sessions, and the study was simultaneously published online in the Lancet[2].

"This atrial-fibrillation–specific management strategy represents a feasible and potentially cost-effective means to improve health outcomes for an increasing number of older individuals presenting with chronic atrial fibrillation and complex comorbidity, in whom recurrent admissions and premature mortality is common," according to Stewart and colleagues.

During the 2-year follow-up, the 168 patients who received the SAFETY intervention spent about 1000 fewer unplanned days in the hospital than the 167 patients who received usual care. "I think that is very clinically significant," Stewart said.

However, up to 1 year, event-free survival was actually worse for patients who received the SAFETY intervention. Then from 1 year to 2 years it was better for those who received the intervention, and at 2 years it was the same in both groups. This highlights the need to look at longer-term outcomes, said Stewart. "My suspicion is . . . the [SAFETY] intervention caught patients earlier, before they had a dramatic event, and that resulted in greater clinical stability that was seen in the length of hospital stay."

Atrial Fibrillation Without Heart Failure

The researchers recruited 355 patients with chronic nonvalvular atrial fibrillation but no heart failure from three tertiary-care hospitals in Adelaide, Melbourne, and Canberra between June 2, 2010 and March 29, 2012.

The patients were randomized to the SAFETY strategy or standard management and had clinical reviews at 12 months and 24 months. Standard management consisted of routine primary care and hospital outpatient-clinic follow-up, including subsidized drugs.

The SAFETY intervention provided more face-to-face and telephone support and included a home visit and Holter monitoring within 1 to 2 weeks of discharge by a cardiac nurse, plus follow-up support from pharmacists, occupational therapists, and other healthcare professionals.

Both patient groups had similar baseline characteristics. On average, they were 72 years old, and almost three-quarters were older than 64; about two-thirds had mild cognitive impairment. About three-quarters had been diagnosed with atrial fibrillation, almost always the persistent form (90%).

Clinicians chose to use a rate- as opposed to a rhythm-control strategy for 64% of the participants. All participants received antiplatelet, anticoagulant, or antiarrhythmic drugs when appropriate.

During a median follow-up of 905 days, the patients had 987 unplanned hospital admissions (5530 days in hospital). Forty-nine patients died, but the study was underpowered to detect between-group differences in mortality.

A total of 76% of patients in the SAFETY intervention group vs 82% of patients in the standard care group died or had an unplanned hospital admission; the difference did not reach significance.

However, patients who received the SAFETY intervention were alive and out of the hospital for a median of 900 of 937 days, which was slightly but significantly higher than the usual-care patients, who were alive and out of the hospital for a median of 860 of 937 days.

Co­–Primary End Points at 2 years, SAFETY Intervention vs Usual Care

End point HR/Effect size (95% CI) P
Event-free survival (HR) 0.97 (0.76–1.23) 0.851
Days alive and out of hospital (effect size) 0.22 (0.21–0.23) 0.039

"Why Such Small Differences?"

"Why did such a carefully developed and comprehensive intervention not lead to greater differences between the well-matched groups?" Dr Pamela J McCabe (Mayo College of Medicine, Rochester, MN) and Dr Holli A DeVon (University of Illinois, Chicago) ask rhetorically in an accompanying comment in the Lancet[3]. Almost half of the unplanned hospital readmissions (46%) were not related to cardiovascular causes, and many of the deaths may have been due to causes other than atrial fibrillation, they suggest.

Importantly, the median length of unplanned hospital stay was only 2.8 days in the SAFETY intervention group vs 3.6 days in the usual-care group, they note.

To explain the lack of a survival benefit, they agree that "the nurse-led home-based management strategy might have detected clinical compromise early and averted events that would otherwise need prolonged treatment, thereby reducing length of stay."

"This is a really meaningful work that addresses a large knowledge gap that we have in terms of this very chronically ill population of patients, in which atrial fibrillation is not necessarily a disease in itself but is a sequel of multiple illnesses," McCabe, who was also the assigned discussant at the AHA session, summarized.

Dr Kim A Williams (Rush University Medical Center, Chicago, IL), the session comoderator, also agreed that the early hospitalizations in the SAFETY group probably averted future events. This is important, because US hospitals are currently penalized for early readmission, whereas readmission may actually improve long-term outcomes, he noted.

More research is needed to tease out which elements of this patient-management strategy work best and how it could be adapted in other countries, Stewart said. "We have a powerful intervention, but it's going to take a bit more time for us to work out the key elements, if we apply that in different setting, particularly in the US," he said.

The study was funded by the National Health and Medical Research Council of Australia. The authors and editorialists have reported they have no relevant financial relationships.


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