Unplanned 30-day readmission, comorbidity, and impact on mortality after incident atrial fibrillation hospitalization in Western Australia, 2001–2015

Long-Term Pattern and Associated Costs of Re-hospitalisations in Patients After Index Atrial Fibrillation Admission in Western Australia, 2011-2017

AIMS

This study aimed to determine total and cardiovascular-specific re-hospitalisation patterns and associated costs within 2 years of index atrial fibrillation (AF) admission in Western Australia (WA).

METHOD

Patients aged 25-94 years, surviving an index (first-in-period) AF hospitalisation (principal diagnosis) from 2011 to 2015 were identified from WA-linked administrative data and followed for 2 years. Person-level hospitalisation costs ($ Australian dollar) were computed using the Australian Refined Diagnosis Related Groups and presented as median with first and third quartile costs.

RESULTS

The cohort comprised 17,080 patients, 59.0% men, mean age 69.6±13.3 (standard deviation) years, and 59.0% had a CHA2DS2-VA (one point for congestive heart failure, hypertension, diabetes mellitus, vascular disease or age 65-74 years; two points for prior stroke/transient ischaemic attack or age ≥75 years) score of 2 or more. Within 2 years, 13,776 patients (80.6%) were readmitted with median of 2 (1-4) readmissions. Among total all-cause readmissions (n=54,240), 40.1% were emergent and 36.6% were cardiovascular-related, led by AF (19.5%), coronary events (5.8%), and heart failure (4.2%). The median index AF admission cost was $3,264 ($2,899-$7,649) while cardiovascular readmission costs were higher, particularly stroke ($10,732 [$4,179-23,390]), AF ablation ($7,884 [$5,283-$8,878]), and heart failure ($6,759 [$6,081-$13,146]). Average readmission costs over 2 years per person increased by $4,746 (95% confidence interval [CI] $4,459-$5,033) per unit increase in baseline CHA2DS2-VA score. The average 2-year hospitalisation costs per patient, including index admission, was $27,820 (95% CI $27,308-$28,333) and total WA costs were $475.2 million between 2011 and 2017.

CONCLUSIONS

Patients after index AF hospitalisation have a high risk of cardiovascular and other readmissions with considerable healthcare cost implications. Readmission costs increased progressively with baseline CHA2DS2-VA score. Better integrated management of AF and coexistent comorbidities is likely key to reducing readmissions and associated costs.

Emergent readmission and long-term mortality risk after incident atrial fibrillation hospitalisation

OBJECTIVE

To assess the frequency and predictors of unplanned readmissions after hospitalisation for incident atrial fibrillation (AF) and the association of readmissions with mortality over 2 years.

METHODS

We performed a retrospective cohort study using Western Australian morbidity and mortality data to identify all patients, aged 25-94 years, who survived incident (first-ever) hospitalisation for AF (principal diagnosis), between 2001 and 2015. Ordinal logistic models determined the covariates independently associated with unplanned readmission(s), and Cox proportional hazards models with time-varying exposures determined the hazard ratios (HR) of one or more readmissions for mortality over 2 years after incident AF.

RESULTS

Of 22 956 patients, 57.7% male, mean age 67.9 (SD 13.8) years, 44.0% experienced 22 053 unplanned readmissions within 2 years, 50.6% being cardiovascular-related. All-cause death occurred in 8.0% of the cohort, and the multivariable-adjusted mortality HR of 1 (vs 0) readmission was 2.9 (95% CI 2.6 to 3.3), increasing to 5.6 (95% CI 5.0 to 6.5) for 3+ readmissions. First emergent readmission for AF, stroke, heart failure or myocardial infarction was independently associated with an increased hazard for mortality. Coexistent cardiovascular and other comorbidities were independently associated with increased readmission and mortality risk, whereas AF ablation was associated with reduced risk.

CONCLUSION

This study highlights the large burden of unplanned all-cause and cardiovascular-specific readmissions within 2 years after being hospitalised for incident AF and their associated adverse impact on mortality. Concomitant comorbidities are independently associated with unplanned hospitalisations and mortality, which supports integrated multidisciplinary management of comorbidities, along with AF-targeted treatments, to improve long-term outcomes in patients with AF.