Renal function after repeat catheter ablation for long-standing persistent atrial fibrillation : Low CHA2DS2-VASc score and sinus rhythm predict improved renal function

Changes in Renal Function in Patients with Recurrence of Atrial Arrhythmia after an Initial Catheter Ablation

BACKGROUND

Impaired renal function and atrial fibrillation (AF) can form a vicious cycle. Although there have been reports on improved renal function in patients who undergo successful AF ablation, renal function in patients with recurrence of AF has not been studied separately. We explored the changes in renal function in recurrent AF patients after catheter ablation with mild renal dysfunction and the influencing factors.

METHODS

We retrospectively recruited nonvalvular AF (NVAF) patients with mildly impaired renal function admitted for catheter ablation and readmitted due to recurrence of AF. The estimated glomerular filtration rate (eGFR) was calculated before the index procedure and during readmission. △eGFR was defined as the difference between eGFR _readmission and eGFR _baseline. The same calculation applied for △CHA₂DS₂-VASc score. The primary endpoint was improved renal function (△eGFR >0) after AF catheter ablation in patients with atrial arrhythmia recurrence.

RESULTS

A total of 132 NVAF patients were included in this study. The mean eGFR at readmission was significantly increased compared with the eGFR at baseline before the index ablation procedure (81.5 ± 1.1 vs. 78.0 ± 0.7 ml/min/1.73 m², P < 0.001). The multivariable Cox regression analysis showed that a lower △CHA₂DS₂-VASc score (HR: 0.42, P=0.003) and paroxysmal recurrent atrial arrhythmia (HR: 2.97, P=0.001) were associated with better renal function.

CONCLUSION

In NVAF patients with mildly impaired renal function, even those with recurrence after the initial catheter ablation, we observed improvements in renal function, which was associated with a lower △CHA₂DS₂-VASc score and paroxysmal recurrent arrhythmia.

Factors associated with renal impairment in Chinese patients with non-valvular AF and without an established renal disease: a cross-sectional study

BACKGROUND

Renal impairment and atrial fibrillation (AF) often coexist. However, risk factors associated with renal impairment in AF patients have not been studied in a large population. Accordingly, this study investigated clinical factors associated with renal impairment in AF patients.

METHODS

From January 2012 to December 2016, 2,298 inpatients with non-valvular AF (NVAF) mainly for catheter ablation were enrolled in this cross-sectional study. Data collection included past medical history, echocardiography measurements, current medicine use and biochemical results. The estimated glomerular filtration rate (eGFR) was calculated using the abbreviated Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Renal impairment was defined as a history of chronic kidney disease or an eGFR ≤90 ml/min/1.73 m². Multivariate logistic regression was conducted to evaluate the relationship between the factors screened and eGFR.

RESULTS

The mean eGFR was 88.6 ± 17.1 ml/min/1.73 m². The overall prevalence of renal impairment was 47.4%. Multivariate logistic regression showed that factors associated with renal impairment were age (OR: 1.12; 95% CI: 1.11-1.14), non-paroxysmal AF (OR: 1.28; 95% CI: 1.04-1.58), use of angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) (OR: 1.58; 95% CI: 1.28-1.95), congestive heart failure (OR: 1.80; 95% CI: 1.05-3.07), left ventricular ejection fraction (LVEF) <50% (OR: 2.39; 95% CI: 1.34-4.28), and prior transient ischemic attack (TIA)/stroke/systematic embolism (SE) (OR: 2.69; 95% CI: 1.68-4.29).

CONCLUSIONS

Renal dysfunction is highly prevalent in Chinese NVAF patients and is significantly associated with older age, non-paroxysmal AF, use of ACEI/ARB, congestive heart failure, LVEF <50% and prior TIA/stroke/SE. Further studies on the mechanisms by which these risk factors affect renal function in NVAF patients need to be conducted.

Five-Year Change in the Renal Function After Catheter Ablation of Atrial Fibrillation

Background

Although it has been reported that renal function can improve after catheter ablation of atrial fibrillation (AF), long‐term changes in renal function and its relationship to rhythm outcomes have not yet been evaluated. We explored the 5‐year change in estimated glomerular filtration rate (eGFR) in AF patients depending on medical therapy and catheter ablation.

Methods and Results

Among 1963 patients who underwent AF catheter ablation and 14 056 with AF under medical therapy in the National Health Insurance Service database, we compared 571 with AF catheter ablation (59±10 years old, 72.3% male, and 66.5% paroxysmal AF) and 1713 with medical therapy after 1:3 propensity‐score matching. All participants had 5 years of serial eGFR data (Chronic Kidney Disease‐Epidemiology Collaboration [CKD‐EPI] method). Catheter ablation improved eGFR_5 yrs (P<0.001), but medical therapy did not. In 2284 matched patients, age (adjusted odds ratio [OR], 0.98 [0.97–0.99]; P<0.001) and AF catheter ablation (adjusted OR, 2.02 [1.67–2.46]; P<0.001) were independently associated with an improved eGFR_5 yrs. Among 571 patients who underwent AF ablation, freedom from AF/atrial tachycardia recurrence after the last AF ablation procedure was independently associated with an improved eGFR_5 yrs (adjusted OR, 1.44 [1.01–2.04]; P=0.043), especially in patients without diabetes mellitus (adjusted OR, 1.78 [1.21–2.63]; P=0.003, P for interaction=0.012). Although underlying renal dysfunction (<60 mL/min/1.73m²) was associated with atrial structural remodeling (adjusted OR, 1.05 [1.00–1.11]; P=0.046), it did not affect the AF ablation rhythm outcome.

Conclusions

AF catheter ablation significantly improved renal function over a 5‐year follow‐up, especially in patients maintaining sinus rhythm without preexisting diabetes mellitus.

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Renal function and outcomes after catheter ablation of patients with atrial fibrillation: The Guangzhou atrial fibrillation ablation registry

INTRODUCTION

Chronic kidney disease (CKD) has been associated with incident atrial fibrillation (AF) and its complications, but data from Asian cohorts are limited.

AIM

To explore the relationship of AF recurrence after catheter ablation (CA) with eGFR as a continuous variable, and with different renal function categories (normal: estimated glomerular filtration rate [eGFR] ≥90mL/min/1.73 m²; mild CKD: eGFR 60-89mL/min/1.73 m²; moderate CKD: eGFR 45-59mL/min/1.73 m²; severe CKD: <45mL/min/1.73 m²), using data from the Guangzhou Atrial Fibrillation Ablation Registry.

METHODS

We studied consecutive symptomatic adult patients with non-valvular AF, refractory to at least one antiarrhythmic drug and eligible for CA, in Guangdong General Hospital between June 2011 and August 2015.

RESULTS

Data were available from 1407 consecutive patients (mean age 57.3±11.5 years; 68% men) with non-valvular AF undergoing radiofrequency or cryoballoon ablation. During a mean follow-up of 20.7±8.8 months, 18.6% of patients with paroxysmal AF and 50.5% with non-paroxysmal AF had AF recurrence. On multivariable analysis, eGFR (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.96-0.97) was an independent risk factor for AF recurrence, with a good predictive value (area under the curve 0.74, 95% CI 0.72-0.77; P<0.01). In the normal renal function, and mild, moderate and severe CKD categories, AF recurrence rates were 11.5%, 29.3%, 72.0% and 93.3%, respectively. Compared with normal renal function, there were stepwise increased risks of AF recurrence with mild CKD (HR 3.30, 95% CI 2.55-4.26; P<0.01), moderate CKD (HR 9.43, 95% CI 6.76-13.16; P<0.01) and severe CKD (HR 12.35, 95% CI 6.93-21.99; P<0.01).

CONCLUSIONS

In a large cohort of Asian patients with AF, renal dysfunction increased the risk of AF recurrence after CA. AF recurrence gradually increased with worsening kidney function in this cohort.