Clinical outcomes associated with cardiac implantable electronic devices

Abstract

The use of cardiac implantable electronic devices (CIEDs) has been increased dramatically in term of numbers as the broadening indications, not only for bradycardia management, but also for treating ventricular arrhythmias and preventing sudden cardiac death. Despite the undeniable benefit of CIED impact in patients with symptomatic conduction disease in prolonging life and improving quality of life, there are some deleterious effects related to long-term exposure to CIED. This thesis evaluates the comprehensive outcomes associated with CIED implantations. In this thesis, literatures were reviewed to allow comprehensive discernment of factors affecting short-term and long-term clinical outcomes of the CIEDs, including the understanding of basic electrochemistry of the CIED generator, factors related to acute complication during CIED implantation procedure, clinical outcomes after implants, and effect of magnetic resonance imaging in CIED. In chapter 2, a comprehensive review of internal and external factors affecting device longevity was performed. The findings demonstrated significant variability in the provided longevity by all manufacturers as no standardised calculation to report the longevity. In this study, standardised numbers of longevity between manufacturers are provided to assist clinician with their clinical decision. In chapter 3, information of prevalence of the short-term complication following CIED implants is provided. This study shows a low rate of complication related to the procedure. Observation from this study have identified that longer procedure time is an independent predictor of complication after CIED implantation procedure. Next three chapters concern the long-term outcomes related to CIEDs. Chapter 4 demonstrates the insight of PH as an unrecognised long-term risk following CIED implants. This study also identified the cardiac structural predictors, with left atrial size and mitral regurgitation as the independent predictors of PH development in CIED population. Chapter 5 provide the evaluation of CIED algorithms, including minimised ventricular pacing (MinVP), atrial preventative pacing (APP), and atrial antitachycardia pacing (aATP), to reduce the risk of deleterious effects related to CIED implantation. These studies failed to show any significant benefit in the utilization of MVP, APP, and aATP algorithm in general CIED with paroxysmal AF population. Nevertheless, our pilot study shown in chapter 6 demonstrated that in the subset of post AF ablation patients, there was a significant reduction in the AT/AF events. In chapter 7, a comprehensive systematic review of the literature and a meta-analysis were conducted to define the safety of magnetic resonance imaging (MRI) in patients with CIEDs, especially non-MRI conditional devices. This study indicates that the use of MRI in non-MRI conditional is safe, inasmuch as a strict selection and monitoring protocol is utilized.