Vascular Dementia, Alzheimer Disease Impact Outcomes in Patients With AF

Patients with atrial fibrillation (AF) and vascular dementia are at higher risk for stroke, hospitalization, and mortality compared with patients with AF and Alzheimer disease (AD) who have a higher risk for intercranial hemorrhage (ICH). These are the findings of a study published in the journal Clinical Cardiology.

Individuals with AF have an elevated risk of developing dementia. It has been posited that varying mechanisms, including hypoperfusion, systemic inflammation, cerebral ischemia, and microbleeds, perform in a synergistic way and contribute to the cognitive decline observed among individuals with AF.

Even though AF has been linked mainly to vascular dementia, recent brain imaging studies have reported increased amyloid deposition in patients with AF, thus implying that degenerative subtypes of dementia, such as AD, are associated with AF as well.

For the study, researchers explored the relationship between dementia subtype and risk for adverse outcomes among individuals with AF via use of the TriNetX global federated database of electronic medical records (EMRs).

The researchers used the TriNetX research network to examine the inclusion of patients with AF between ages 18 and 80.

Participants with AF were classified into 1 of 2 groups, based on the occurrence of AD or vascular dementia, with the groups balanced via the use of propensity score matching (PSM). The dates selected in the study permitted 4 years of follow-up within the participating HCOs. Outcome measures were as follows:

• ICH
• Composite of ischemic stroke/transient ischemic attack (TIA)
• Hospitalizations
• All-cause mortality

A total of 2,377 individuals with AF and a dementia diagnosis were identified, with 1,225 patients (mean age, 66.0±6.4; 37.3% women) diagnosed with vascular dementia and 1,152 patients (mean age, 67.9±6.1 years; 43.7% women) diagnosed with AD.

The researchers found that patients who had AF and AD were significantly older
(P <.001), primarily of non-Hispanic White ethnicity, and presented with a lower cardiovascular (CV) risk profile (ie, lower prevalence of hypertension, heart failure, ischemic heart disease, and diabetes) compared with those with AF and vascular dementia (P <.05 for all).

After the application of PSM, a total of 615 patients were included in each of the 2 cohorts. Incident ICH was reported among 3.6% (22 of 615) of patients with AF and vascular dementia vs 8.9% (55 of 615) of those with AF and AD during the 4 years of follow-up. The risk for ICH was greater among patients with AF and AD than among those with AF and vascular dementia (hazard ratio [HR], 2.22; 95% CI, 1.33-3.70; log-rank P =.002).

Over the 4-year follow-up period, 38.5% (237 of 615) of participants with vascular dementia and AF vs 31.4% (193 of 615) of those with AD and AF experienced an ischemic stroke/TIA. The risk for ischemic stroke/TIA was 1.32-fold higher among those with vascular dementia and AF compared with those with AD and AF (HR, 1.32; 95% CI, 1.09-1.59; log-rank P = .003).

Over 4 years, 66.0% (406 of 615) of patients with AF and vascular dementia vs 62.1% (382 of 615) of those with AF and AD were hospitalized. The risk for being hospitalized was 1.14-fold higher among participants with vascular dementia and AF than among those with AD and AF (HR, 1.14; 95% CI, 1.01-1.31; log-rank P = .048). Additionally, mortality was higher among individuals with AF and vascular dementia compared with those with AF and AD (HR, 1.25; 95% CI, 1.01-1.58; log-rank P = .049).

“Considering our results, there is a need for a more holistic or integrated care approach to patients with AF, which has been associated with an improved clinical prognosis,” the researchers noted. “Such an integrated management should also consider dementia risk, as it not only impacts on cognitive decline and quality of life but also on the risk of other subsequent worse clinical outcomes.”

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.