Factors influencing inappropriate device therapy in implantable cardioverter defibrillators: a predictive analysis
Authors: Huntelaar M J , Krabbenborg J , Van Der Lingen A C J , Hopman L H G A , Rijnierse M T , Kemme M J B , Allaart C P , Van Halm V P 
Published: May 2024

Abstract

Background
Implantable cardioverter defibrillator (ICD) implantation and subsequent ICD therapy have shown to be efficacious in the prevention of sudden cardiac death. However, patients with an ICD are at risk of inappropriate device therapy (IDT), which is associated with worse outcomes, reduced quality of life (QoL), and may influence psychosocial and mental wellbeing.

Purpose
This study aimed to predict which patients are at risk of IDT by investigating the influence of pre-implant clinical parameters on occurrence of IDT.

Methods
From January 2010 to December 2019, patients who received an ICD in our medical center, were included in a prospective registry. Only patients with ICD (including ICDs used for cardiac resynchronization therapy, i.e. CRT-D) with an atrial lead were included in the current analysis, to better distinguish between appropriate and inappropriate device therapy. After implant, the device was interrogated at least every 6 months and clinical symptoms related to the device, recorded events, and relevant technical setting changes were recorded. IDT was defined as antitachycardia pacing (ATP) or shock delivered for any reason other than ventricular arrhythmia. Follow-up ended after IDT, death, or loss-to-follow-up.

Results
428 patients underwent an implantation of a dual chamber ICD or CRT-D of various manufacturers. 14 patients were lost to follow-up within the first year and one patient was excluded because of a dislocated atrial lead, leaving 413 patients (76% male, mean age 67±9.7 years, 39% CRT-D) with a minimum of 1-year follow-up. During a mean of 5.3 (±3.0) years, 136 (32.9%) patients received appropriate therapy and 36 (8.7%) patients received IDT. Of those 36 patients, 18 patients received only ATP, 12 received ATP followed by a shock, and 6 patients received a shock without prior ATP. The median time from implantation to IDT was 2.8 [0.3-5.8] years. Univariate logistic regression on 40 clinical parameters followed by a forward multivariate logistic regression was performed. The area under the ROC curve of the resulting multivariate model was 0.724 (95%CI 0.622-0.826). Cox regression analysis resulted in device type (CRT-D) (HR=0.533, 95%CI 0.234-1.211, p=0.133), use of mineralocorticoid receptor-antagonists (MRA) (HR=0.280, 95%CI 0.104-0.754, p=0.012), use of diuretics (HR=3.378, 95%CI 1.479-7.714, p=0.004), and eGFR (HR=1.217, 95%CI 0.972-1.523, p=0.087) as predictors of IDT. A history of atrial fibrillation was not a significant predictor of IDT.

Conclusion
This study identified CRT-D and use of MRAs to be protective against IDT, and use of diuretics and lower eGFR as risk factors of IDT. To inform patients optimally, pre-implant assessment of those factors could help identify patients at higher risk of IDT. Furthermore, it could dictate more cautious device programming and consequently reduce rates of IDT, reducing the negative influence of IDT on QoL and wellbeing in the ICD population.