Predictors of Mortality in Patients with Implantable Cardiac Defibrillators: A Mix Cohort Study

Abstract

Background and Objective: Implantable Cardioverter Defibrillator (ICD) insertion is a common therapeutic method for patients at risk of sudden cardiac death due to ventricular arrhythmias. The present research aimed to identify predictive factors for mortality in patients undergoing ICD implantation. Materials and Methods: In this mix-cohort study, 225 patients undergoing ICD placement were enrolled through a census from March 2017 to March 2021 at Farshchian Heart Center in Hamadan, Iran. The patients' demographic characteristics and blood tests were collected by accessing their electronic records and conducting telephone interviews. Participants were followed up to investigate the factors that influence the death. The Cox regression model was performed using Stata software (version 14) to identify predictive factors for premature mortality. Results: The survey results from the study of 225 individuals indicated that 183 people (80.88%) were male, 91 people (40.44%) were in the age group of 55-65 years, and 87 people (34.66%) were in the age group above 65 years. Moreover, 25 cases (11.1%) of death occurred, with 1, 2, 3, and 4-year survival rates of 96.3%, 93%, 83.2%, and 83.2%, respectively. Additionally, being older than 65 years (hazard ratio [HR] 5.84, CI: 1.20, 21.89) was associated with an increased risk of mortality, while ejection fraction greater than 15% (HR 0.22, CI: 0.06, 0.76) was associated with a decreased risk of mortality following ICD implantation. Conclusion: In this study, being older than 65 years and an ejection fraction of less than 15% were associated with an increased risk of mortality following ICD implantation. Given the negative outcomes, the follow-up of these patients should be conducted with greater precision.

Keywords

• implantable defibrillator
• mortality
• risk factors
• survival