The Risk of Stroke and Stroke Type in Patients With Atrial Fibrillation and Chronic Kidney Disease.

BACKGROUND

Atrial fibrillation (AF) and chronic kidney disease (CKD) are known to increase the risk of stroke.

OBJECTIVES

We set out to examine the risk of stroke by kidney function and albuminuria in patients with and without AF.

DESIGN

Retrospective cohort study.

SETTINGS

Ontario, Canada.

PARTICIPANTS

A total of 736 666 individuals (>40 years) from 2002 to 2015.

MEASUREMENTS

New-onset AF, albumin-to-creatinine ratio (ACR), and an estimated glomerular filtration rate (eGFR).

METHODS

A total of 39 120 matched patients were examined for the risk of ischemic, hemorrhagic, or any stroke event, accounting for the competing risk of all-cause mortality. Interaction terms for combinations of ACR/eGFR and the outcome of stroke with and without AF were examined.

RESULTS

In a total of 4086 (5.2%) strokes (86% ischemic), the presence of AF was associated with a 2-fold higher risk for any stroke event and its subtypes of ischemic and hemorrhagic stroke. Across eGFR levels, the risk of stroke was 2-fold higher with the presence of AF except for low levels of eGFR (eGFR < 30 mL/min/1.73 m, hazard ratio [HR]: 1.38, 95% confidence interval [CI]: 0.99-1.92). Similarly across ACR levels, the risk of stroke was 2-fold higher except for high levels of albuminuria (ACR > 30 mg/g, HR: 1.61, 95% CI: 1.31-1.99). The adjusted risk of stroke with AF differed by combinations of ACR and eGFR categories (interaction value = .04) compared with those without AF. Both stroke types were more common in patients with AF, and ischemic stroke rates differed significantly by eGFR and ACR categories.

LIMITATIONS

Medication information was not included.

CONCLUSIONS

Patients with CKD and AF are at a high risk of total, ischemic, and hemorrhagic strokes; the risk is highest with lower eGFR and higher ACR and differs based on eGFR and the degree of ACR.