The interplay between atrial fibrillation and heart failure on long-term mortality and length of stay: Insights from the, United Kingdom ACALM registry

Background There is concern that the development of heart failure and atrial fibrillation has a detrimental influence on clinical outcomes. The aim of this study was to assess all-cause mortality and length of hospital stay in patients with chronic and new-onset concomitant AF and HF. Methods Using the ACALM registry, we analysed adults hospitalised between 2000 and 2013 with AF and HF and assessed prevalence, mortality and length of hospital stay. Patients with HF and/or AF at baseline (study-entry) were compared with patients who developed new-onset disease during follow-up. Results Of 929,552 patients, 31,695 (3.4%) were in AF without HF, 20,768 (2.2%) had HF in sinus rhythm, and 10,992 (1.2%) had HF in AF. Patients with HF in AF had the greatest all-cause mortality (70.8%), followed by HF in sinus rhythm (64.1%) and AF alone (45.1%, p < 0.0001). Patients that developed new-onset AF, HF or both had significantly worse mortality (58.5%, 70.7% and 74.8% respectively) compared to those already with the condition at baseline (48.5%, 63.7% and 67.2% respectively, p < 0.0001). Patients with HF in AF had the longest length of hospital stay (9.41 days, 95% CI 8.90–9.92), followed by HF in sinus rhythm (7.67, 95% CI 7.34–8.00) and AF alone (6.05, 95% CI 5.78–6.31). Conclusions Patients with HF in AF are at a greater risk of mortality and longer hospital stay compared to patients without the combination. New-onset AF or HF is associated with significantly worse prognosis than long-standing disease.