Predictors of Atrial High‐Rate Episodes and Inappropriate Device Therapy in Implantable Cardioverter Defibrillators

Background Implantable cardioverter defibrillator (ICD) therapy can prevent sudden cardiac death, but poses a risk of inappropriate device therapy (IDT), which is linked to worse outcomes and reduced quality of life. On the other hand, ICDs can function as an early warning system for atrial arrhythmias. Purpose This study aimed to predict which patients are at risk of IDT and who develop atrial high‐rate episodes (AHRE) by investigating pre‐implant clinical parameters. Methods Patients who received an ICD with an atrial lead between 2010 and 2019 were included in a prospective registry. Results Over 5.3 ± 3.0 years, 136 of 413 patients received appropriate device therapy, and 36 patients received IDT. Univariate cox regression analyses on 40 parameters were performed, followed by forward multivariate cox regression. The best predictive model (Harrell's C‐index 0.785) included secondary prevention ICD, ischemic CMP (iCMP), CMP not classified as ischemic, hypertrophic or dilated (uCMP), and diuretic use as risk factors, with mineralocorticoid receptor‐antagonists (MRA) use and diabetes as protective factors. Surprisingly, AF was not a predictor of IDT. Among 313 patients without prior AF, 136 developed AHRE. Similar cox regressions predicted AHRE development, resulting in a model (Harrell's C‐index 0.663) based on age, left ventricular ejection fraction (LVEF), hypertrophic CMP (hCMP), family history of cardiovascular disease (CVD), and hypercholesterolemia. Conclusion This study identified six factors that influence the risk of IDT, and five other factors as risk factors for developing AHRE. Pre‐implant assessment of these variables can help to better inform patients of the potential benefits and risks.