Long-Term Follow-Up of Patients With Tetralogy of Fallot and Implantable Cardioverter Defibrillator

Abstract

Background: Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, and sudden cardiac death represents an important mode of death in these patients. Data evaluating the implantable cardioverter defibrillator (ICD) in this patient population remain scarce. Methods: Nationwide French Registry including all TOF patients with an ICD initiated in 2010 by the French Institute of Health and Medical Research. The primary time to event endpoint was the time from ICD implantation to first appropriate ICD therapy. Secondary outcomes included ICD-related complications, heart transplantation, and death. Clinical events were centrally adjudicated by a blinded committee. Results: A total of 165 patients (mean age 42.2±13.3 years, 70.1% males) were included from 40 centers, including 104 (63.0%) in secondary prevention. During a median (IQR) follow-up of 6.8 (2.5-11.4) years, 78 (47.3%) patients received at least one appropriate ICD therapy. The annual incidence of the primary outcome was 10.5% (7.1% and 12.5% in primary and secondary prevention, respectively, p=0.03). Overall, 71 (43.0%) patients presented with at least one ICD complication, including inappropriate shocks in 42 (25.5%) patients and lead dysfunction in 36 (21.8%) patients. Among 61 (37.0%) primary prevention patients, the annual rate of appropriate ICD therapies was 4.1%, 5.3%, 9.5%, and 13.3% in patients with respectively no, one, two, or ≥ three guideline-recommended risk factors. QRS fragmentation was the only independent predictor of appropriate ICD therapies (HR 3.47, 95% CI 1.19-10.11), and its integration in a model with current criteria increased the 5-year time-dependent area under the curve from 0.68 to 0.81 (p=0.006). Patients with congestive heart failure and/or reduced LVEF had a higher risk of non-arrhythmic death or heart transplantation (HR=11.01, 95% CI: 2.96-40.95). Conclusions: Patients with TOF and an ICD experience high rates of appropriate therapies, including those implanted in primary prevention. The considerable long-term burden of ICD-related complications, however, underlines the need for careful candidate selection. A combination of easy-to-use criteria including QRS fragmentation might improve risk stratification. Clinical Trial Registration: URL: https://clinicaltrials.gov Unique Identifier: NCT03837574

QRS Duration During Follow-Up of Tetralogy of Fallot: How Valuable is it? Analysis of ECG Changes in Relation to Pulmonary Valve Implantation

“…This is electrophysiologically represented by QRS prolongation [16,17], as a result of surgical scarring combined with progressive RV dilation. Until now, a QRS > 180 ms is considered as a risk factor for sudden cardiac death [18] remaining a major criterium for an implantable cardiac defibrillator (ICD) in primary prevention [19] and still a valid risk factor adopted in the recently published 2020 ESC guidelines for adult congenital heart disease [20].…”

Moving beyond size: vorticity and energy loss are correlated with right ventricular dysfunction and exercise intolerance in repaired Tetralogy of Fallot

“…B Volumetric representation of vorticity also demonstrates the ring-vortex as shown. The calculation of RV Diastolic Vorticity Quotient (RV-DVQ) in RTOF patients demonstrates the influence of vorticity from RVOT; whereas in RVD and control cases, vorticity from RV inflow remains dominant be optimized to prevent long-term, irreversible consequences of RV dysfunction such as ventricular arrhythmias, exercise intolerance and overt systolic dysfunction [6,[29][30][31]. To date the International Multicenter TOF Registry (INDICATOR), a multi-center international cohort study, provides the best interpretation of RV dysfunction in rTOF patients by CMR, identifying RVEF as a significant risk factor for death and ventricular tachycardia [32].…”

Arrhythmias in Repaired Tetralogy of Fallot: A Scientific Statement From the American Heart Association

“…48 In a long-term follow-up study of patients with repaired TOF and ICDs, fQRS was the only risk factor independently associated with appropriate ICD therapy in patients with primary prevention ICDs. 38 Circ Arrhythm Electrophysiol. 2022;15:e000084.…”

“…71,72 The risk of inappropriate shock appears to be higher in patients with AAs. 2,14,38 Therefore, in patients with AAs, the risk of inappropriate shock might be mitigated by programming of appropriate detection zones and rate control with atrioventricular node-blocking agents.…”