# Reduced Kidney Function and Left Atrial Dilatation as Predictors of Incident Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy

## TL;DR

This study finds that reduced kidney function and enlarged left atrium are linked to a higher risk of developing atrial fibrillation in patients with hypertrophic cardiomyopathy.

## Contribution

The study identifies reduced eGFR and left atrial dilatation as independent predictors of new-onset AF in HCM patients.

## Key findings

- 21.7% of HCM patients developed new-onset AF over a median follow-up of 7.52 years.
- Reduced eGFR and increased left atrial diameter were independently associated with AF onset.
- Patients with eGFR ≤ 76.1 mL/min/1.73 m2 or LAD ≥ 48.0 mm had significantly higher AF incidence.

## Abstract

Atrial fibrillation (AF), the most frequently occurring sustained arrhythmia in patients with hypertrophic cardiomyopathy (HCM), is linked to poor quality of life and increased thromboembolic risk. Chronic kidney disease (CKD) and reduced kidney function are known cardiovascular risk factors; however, their contributions to new‐onset AF in patients with HCM remain unclear. Estimated glomerular filtration rate (eGFR) is a key marker for CKD management. This study aimed to elucidate the incidence of new‐onset AF and to identify predictive factors in patients with HCM.

We analyzed 198 patients with HCM (121 men; mean age, 58 ± 17 years) without prior AF. The incidence and predictors of new‐onset AF were evaluated with a focus on kidney function and left atrial (LA) size. Cox proportional hazards modeling was used to assess the associations.

Impaired kidney function (eGFR < 60 mL/min/1.73 m2) was present in 35 patients (17.7%). Over a median follow‐up of 7.52 years, 43 patients (21.7%) developed new‐onset AF for an incidence rate of 2.8 per 100 person‐years. The multivariate analysis identified reduced eGFR and increased LA diameter (LAD) as independent predictors of AF. Kaplan–Meier curves showed a significantly higher cumulative AF incidence among patients with an eGFR ≤ 76.1 mL/min/1.73 m2 or an LAD ≥ 48.0 mm.

Decreased kidney function and LA dilatation were significantly associated with new‐onset AF among patients with HCM. These findings suggest that this patient population requires closer monitoring for the early detection of AF.

New‐onset atrial fibrillation (AF) occurred in 22% of patients with hypertrophic cardiomyopathy, corresponding to an incidence rate of 2.8 per 100 person‐years. Reduced kidney function and left atrial dilatation were independently associated with AF onset, indicating the need for closer monitoring and regular renal assessments in this population.