Impact of Atrial Fibrillation on Hospitalization Outcomes of Heart Failure in Patients ≥ 60 Years with Implantable Cardioverter Defibrillator

https://doi.org/10.1016/j.amjcard.2021.04.016Get rights and content

The impact of atrial fibrillation (AF) on the hospitalization outcomes in patients ≥ 60 years of age with implantable cardioverter defibrillators (ICD) is not well studied. We queried the National Inpatient Sample database for all patients aged ≥ 60 who had a history of ICD placement, and were admitted with a primary diagnosis of heart failure (HF) during the years 2016-2017. Patients were stratified into 2 groups based on their history of AF. The primary outcome of the study was all-cause in-hospital mortality. Secondary outcomes included cardiogenic shock, myocardial infarction (MI), ventricular fibrillation (VF), stroke and acute kidney injury (AKI). The association between different age strata and outcomes was investigated. The hospitalization outcomes were modeled using logistic regression. A total of 178,045 patients were included, of whom 56.2% had AF. AF correlated with increased mortality (A-OR 1.22 (95% CI: 1.06-1.4), p=0.005), cardiogenic shock (A-OR 1.21 (95%CI: 1.08-1.36), p<0.001), AKI (A-OR 1.12 (95%CI: 1.06-1.17), p<0.001 and lower risk for MI (A-OR 0.79 (95% CI: 0.68-0.9), p<0.001. There was no correlation between AF and risk for VF or stroke. A significant correlation between AF and higher risk for mortality, cardiogenic shock and AKI was demonstrated in ages ≤ 75, ≤ 75, and ≤ 80 years, respectively. In contrast, a significant correlation between AF and lower risk for MI is only demonstrated at age > 70 years. We conclude that AF is an independent predictor for increased all-cause in-hospital mortality and cardiogenic shock. Such risk is influenced by age.

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Methods

This study was conducted using the publicly available National Inpatient Sample (NIS) of the Health Care Utilization Project (HCUP) sponsored by the Agency for Healthcare Research and Quality. Information about the registry has been previously described.7

All HF patients aged ≥ 60 who were diagnosed with a history of ICD placement, and were admitted with a primary diagnosis of HF during the years 2016 to 2017 were included (Supplement Table 1). Patients with history of ICD placement were

Results

We included a total of 178,045 patients with a history of HF and ICD placed who were hospitalized for HF symptoms during the years 2016 to 2017. Table 1 summarizes the baseline characteristics of the study population. Patients with AF accounted for 56.2% of the total study population. Patients with AF were older with median age (75 vs 72 years, SMD=0.3) had less proportion of females (26.7% vs 32.3% SMD=0.1), higher proportions of white race (71.4% vs 57.4%, SMD=0.3) and had higher prevalence

Discussion

The key findings in this study are: 1. AF is highly prevalent in hospitalized older patients with HF and ICDs. 2. AF is an independent predictor for increased all-cause in-hospital mortality and cardiogenic shock. 3. This increased risk for mortality and cardiogenic shock is age dependent, and counter-intuitively, risk decreases with advancing age and essentially becomes insignificant in patients older than 75 years. Perhaps this relationship can be explained by an increase in competing risks

Authors contribution

AA: Conceptualization, Methodology, Resources, Formal analysis, Visualization, Writing, review & eiditing.

AE, AO, HA: Writing - review & editing.

MA: Formal analysis, review & editing

AV: Supervision, Methodology, Writing review & editing.

Disclosure

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

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