Kidney function and appropriateness of device therapies in adults with implantable cardioverter defibrillators

Association of Kidney Function With Risk of Adverse Effects of Therapies for Atrial Fibrillation

Introduction

Atrial fibrillation (AF) is common in chronic kidney disease (CKD) and is treated with rate control medications, antiarrhythmic medications, as well as anticoagulation and procedures, each of which have associated risks. We aimed to evaluate the association of CKD status with the risks of adverse effects after initiation of AF therapies.

Methods

This was a cohort study of community-based adults who newly initiated rate control medications, antiarrhythmic medications, warfarin, direct oral anticoagulants (DOACs) or received AF procedures in the 1 year after diagnosis of AF. Baseline estimated glomerular filtration rate (eGFR) was calculated using outpatient serum creatinine measures. Adverse effects within 1 year related to each AF therapy or within 1 month of an AF procedure were ascertained from vital sign databases, electrocardiograms (ECGs), and administrative codes. Fine-Gray hazard models were used to study the association of eGFR categories with risk of adverse effects for each AF therapy.

Results

Among 115,564 patients with incident AF, lower eGFR (vs. eGFR ≥60 ml/min per 1.73 m²) was significantly associated with higher adjusted risk of adverse effects after initiation of rate control therapies (most commonly hypotension and bradycardia) as follows: eGFR 45-59 (hazard ratio [HR] 1.14, 95% confidence interval [CI] 1.07-1.22), 30-44 (HR 1.15, 95% CI 1.06-1.25), and 15-29 (HR 1.29, 95% CI: 1.12-1.47) ml/min per 1.73 m². Lower eGFR was associated with higher adjusted risk of adverse effects (most commonly prolonged QRS and QTc intervals) after initiation of an antiarrhythmic medication (vs. eGFR >60 ml/min per 1.73 m²) as follows: eGFR 45-59 (HR 1.12, 95% CI 1.01-1.23) and eGFR<15 (HR 1.43, 95% CI 1.01-2.01) ml/min per 1.73 m².

Conclusion

There was a graded association between lower eGFR and risk of major bleeding with warfarin use, with the greatest risk among those with eGFR <15 ml/min per 1.73 m² (HR of 2.93, 95% CI 1.99-4.30). There was no association of eGFR with major bleeding in patients receiving DOACs. Rates of adverse effects within 1 month of an AF procedure were low among patients with (n = 18) and without (n = 41) CKD and was underpowered for further analyses. In conclusion, lower eGFR was associated with significantly higher risks of adverse effects after initiation of commonly used therapies to treat AF. These data may help inform the complex therapeutic decisions in patients with CKD and AF.

Incidence and Predictors of Implantable Cardioverter-defibrillator Therapies After Generator Replacement-A Pooled Analysis of 31,640 Patients' Data

Among primary prevention implantable cardioverter-defibrillator (ICD) recipients, 75% do not experience any appropriate ICD therapies during their lifetime, and nearly 25% have improvements in their left ventricular ejection fraction (LVEF) during the lifespan of their first generator. The practice guidelines concerning this subgroup's clinical need for generator replacement (GR) remain unclear. We conducted a proportional meta-analysis to determine the incidence and predictors of ICD therapies after GR and compared this to the immediate and long-term complications. A systematic review of existing literature on ICD GR was performed. Selected studies were critically appraised using the Newcastle-Ottawa scale. Outcomes data were analyzed by random-effects modeling using R (R Foundation for Statistical Computing, Vienna, Austria), and covariate analyses were conducted using the restricted maximum likelihood function. A total of 31,640 patients across 20 studies were included in the meta-analysis with a median (range) follow-up of 2.9 (1.2-8.1) years. The incidences of total therapies, appropriate shocks, and anti-tachycardia pacing post-GR were approximately 8, 4, and 5 per 100 patient-years, respectively, corresponding to 22%, 12%, and 12% of patients of the total cohort, with a high level of heterogeneity across the studies. Greater anti-arrhythmic drug use and previous shocks were associated with ICD therapies post-GR. The all-cause mortality was approximately 6 per 100 patient-years, corresponding to 17% of the cohort. Diabetes mellitus, atrial fibrillation, ischemic cardiomyopathy, and the use of digoxin were predictors of all-cause mortality in the univariate analysis; however, none of these were found to be significant predictors in the multivariate analysis. The incidences of inappropriate shocks and other procedural complications were 2 and 2 per 100 patient-years, respectively, which corresponded to 6% and 4% of the entire cohort. Patients undergoing ICD GR continue to require therapy in a significant proportion of cases without any correlation with an improvement in LVEF. Further prospective studies are necessary to risk-stratify ICD patients undergoing GR.