Tetralogy of Fallot Surgical Repair and Associated Right Ventricular Remodeling

Abstract

Tetralogy of Fallot (TOF) is the most common cyanotic congenital cardiac defect with a global annual incidence of 40,000 cases. Advances in surgery and perioperative care led to improvements in perioperative mortality and, thus, a growing number of survivors. TOF survivors often suffer from complications related to a failing right ventricle. Follow-up studies evaluating TOF repair strategies suggest an association between the type of surgical repair strategy and late right ventricular health. However, surgical practices remain unchanged and led by institution-level biases. The body of evidence addressing outcomes based on TOF surgical repair strategy is weak and controversies persists on the management of these patients. This thesis comprises 6 chapters that form the foundation of a multi-centre research program on outcomes after TOF surgical repair. The program uses various methodologies to generate evidence with a vision to change surgical practices. Chapter 1 is an introduction providing background on TOF and contemporary areas of controversy. Chapter 2 presents the results of a retrospective analysis evaluating the use of early echocardiogram parameters in predicting late cardiac magnetic resonance imaging evaluation of the right ventricle. Chapter 3 presents the results of a retrospective cohort exploring the association between TOF repair strategy and development of right bundle branch block. Chapter 4 presents the results of a multinational survey aiming to explore contemporary biases in TOF surgical repair strategy selection. Chapter 5 presents the background, rationale, design and baseline cohort characteristics of the Tetralogy of Fallot for Life (TOF LIFE) study. The study is a multi-centre inception cohort study with a follow-up period of 2 years. Finally, Chapter 6 discusses the conclusion, limitations, and future implications of this research program.