The Relationship Between Cardiologist Care and Clinical Outcomes in Patients With New-Onset Atrial Fibrillation

Background: Increased mortality is well described in patients with atrial fibrillation (AF), primarily related to death from cardiovascular causes. One may hypothesize that cardiology care may be associated with a reduction in cardiovascular deaths in patients with AF, thereby improving their overall survival. The aim of this study was to assess the association between cardiologist care and clinical outcomes, including all-cause mortality, in patients with new-onset AF. Methods: This was a retrospective population-level, propensity score-matched cohort study of patients aged 20-80 years with new-onset AF presenting to an emergency department in Ontario, Canada between 2010 and 2012. Patients who saw a cardiologist within 1 year of the initial diagnosis were matched to patients who did not see a cardiologist. Linked administrative databases were used for cohort construction and allow for 1-year follow-up to assess for the clinical end points of death, hospitalization for AF, stroke syndromes, bleeding, and heart failure. Results: Cardiologist care was associated with a lower 1-year rate of death (5.3% vs 7.7%; hazard ratio, 0.68; 95% confidence interval, 0.55-0.84), despite an increased rate of hospitalizations for AF (17.9% vs 8.2%), stroke syndromes (1.7% vs 0.5%), bleeding (3.1% vs 2.0%), and heart failure (3.2% vs 1.4%). Conclusions: Cardiologist care was associated with a reduction in death in patients with new-onset AF. Further study to obtain a greater understanding of the processes of care associated with the observed survival improvement is warranted.