Patients hospitalized for atrial fibrillation in rural hospitals were more likely to die than patients admitted to urban hospitals, according to a cross-sectional analysis involving close to 250,000 hospitalizations.
Rural hospital admission was associated with a 17% increased risk of death, compared with admission to urban hospitals in the adjusted multivariate model, reported Wesley T. O’Neal, MD, of Emory University School of Medicine in Atlanta, and colleagues.
Multivariate modelling adjusted for potential mortality confounders and propensity score-matched analysis both showed rural hospital mortality to be higher, as did subgroup analyses by sex, race, and region, they wrote in HeartRhythm.
The findings suggest that improvements in atrial fibrillation (AF) care could reduce mortality in rural hospital settings, they added, stating that “Further research is needed to understand the reasons for this finding and suggest that improvement in AF care in rural hospitals is needed to further reduce the risk of mortality associated with hospital admission for AF.”
Hospitalizations for atrial fibrillation have increased dramatically in the U.S. in recent years, with one study showing a 23% increase in a single decade (2000-2010).
The researchers noted that at least half a dozen studies published since 2000 suggest that quality of care, as well as outcomes, for patients hospitalized for cardiovascular causes varies between urban and rural hospitals. They added that mortality differences among patients admitted for atrial fibrillation have not been previously studied.
“Less optimal care of patients with AF has been reported in rural compared to urban areas, which supports the possibility of poorer outcomes in patients with AF admitted to rural hospitals,” they wrote.
In their cross-sectional examination of patients hospitalized for atrial fibrillation, the researchers analyzed data from the National Inpatient Sample for the period 2012 through 2014.
Hospitals were classified as urban or rural based on core-based statistical areas, while in-hospital mortality was defined as death due to any cause during hospitalization.
The mean age of the 248,785 patients included in the analysis was 69; 78% were white; and 48% were women. Also, 88% received treatment at urban hospitals and 12% were treated at rural hospitals.
Among the main findings, a higher percentage of patients admitted for atrial fibrillation died in rural hospitals compared to urban hospitals (1.3% versus 1.0%, P<0.001).
Patients admitted to rural hospitals had an increased risk for death compared with those admitted to urban hospitals in the multivariate model accounting for differences in patient characteristics (OR, 1.17, 95% CI 1.04 to 1.32).
The elevated death risk associated with urban hospital admission persisted after exclusion of patients who had external electrical cardioversion or catheter ablation procedures (OR, 1.14, 95% CI 1.01 to 1.28).
Similar results were seen in a propensity score-matched cohort and in subgroup analyses by sex, race, and region.
Patients admitted to urban hospitals for atrial fibrillation were more likely to have secondary diagnoses of heart failure, hyperlipidemia, and acute kidney injury than those from rural hospitals.
The researchers noted that the risk of in-hospital mortality in patients admitted for atrial fibrillation has actually declined in recent years, due, in part, to the greater use of treatments like external electrical cardioversion and catheter ablation.
They added that while the reasons for the observed rural hospital death increase are unclear, “differences in practice patterns possibly explain this finding.”
Eight percent of the patients in the cohort admitted to urban hospitals received external electrical cardioversion versus 4% of patients treated at rural hospitals (P<0.001), while 9% of patients treated at urban hospitals received catheter ablation, compared with just 1% of patients treated at rural hospitals.
In an accompanying editorial, Thomas Deering, MD, and Ashish Bhimani, MD, of the Piedmont Heart Institute in Atlanta, wrote that while some studies have shown inequities in atrial fibrillation care in rural hospitals, others have shown no significant differences in care compared with non-rural hospitals.
“If the higher rural AF mortality rates noted in the study by O’Neal et al were related primarily to the delivery of AF care, one might expect to see higher cardiovascular and/or stroke-related mortality rates and not just overall higher mortality rates,” they wrote. “Unfortunately, the methodologic design of this study precludes such an analysis. Furthermore, the small absolute mortality difference between rural (1.3%) and urban (1.0%) patients, in which the reasons for those differences remain unknown, makes it difficult to determine the clinical importance of the observed results and suggest effective health policy approaches.”
Study limitations included the inability to distinguish between cases of new-onset and preexisting atrial fibrillation and lack of information on cause of death.
The study was funded by the National Heart, Lung, and Blood Institute.
O’Neal and co-authors, as well as Deering and Bhimani, disclosed no relevant relationships with industry.
Robert Jasmer, MD Associate Clinical Professor of Medicine, University of California, San Francisco and Dorothy Caputo, MA, BSN, RN, Nurse Planner