Impact of proteinuria and glomerular filtration rate on risk of thromboembolism in atrial fibrillation: the...

Area of Science:

• Cardiology
• Nephrology
• Stroke Prevention

Background:

• Atrial fibrillation (AF) is a known risk factor for ischemic stroke.
• Current risk stratification models for stroke in AF have limitations.
• The independent impact of chronic kidney disease (CKD) on stroke risk in AF patients is not well-established.

Purpose of the Study:

• To investigate the association between chronic kidney disease (CKD) and thromboembolism risk in patients with atrial fibrillation (AF).
• To determine if reduced glomerular filtration rate (eGFR) or proteinuria independently increases stroke risk in AF patients.
• To evaluate the utility of kidney function parameters in refining stroke risk stratification for AF.

Main Methods:

• Retrospective analysis of laboratory and clinical databases for 10,908 AF patients.
• Estimation of glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease (MDRD) equation.
• Assessment of proteinuria via urine dipstick results.
• Ascertainment of thromboembolic events over 33,165 person-years off anticoagulation, with chart review validation.

Main Results:

• Proteinuria was associated with a 54% increased risk of thromboembolism (RR, 1.54; 95% CI, 1.29-1.85) after adjusting for confounders.
• A graded increase in stroke risk was observed with decreasing eGFR levels.
• Patients with eGFR < 45 mL/min/1.73 m² had a 39% higher risk of thromboembolism (RR, 1.39; 95% CI, 1.13-1.71) compared to eGFR ≥ 60 mL/min/1.73 m² (P-trend = 0.0082).

Conclusions:

• Chronic kidney disease, including reduced eGFR and proteinuria, independently increases thromboembolism risk in AF patients.
• Incorporating kidney function and proteinuria assessment into risk stratification can improve decision-making for antithrombotic therapy in AF.
• These findings highlight CKD as a critical factor in stroke prevention strategies for individuals with atrial fibrillation.