Risk Factors for Mortality and Ventricular Tachycardia in Patients With Repaired Tetralogy of Fallot: A Systematic Review and Meta-analysis

Background: Patients with repaired tetralogy of Fallot (rTOF) have increased risk for mortality, sudden cardiac death, and ventricular tachycardia (VT). The aim of this systematic review and meta-analysis is to offer an updated analysis of risk factors following significant changes in surgical and perioperative management. Methods: A meta-analysis based on the published literature between 2008 and 2018 was conducted. Endpoints were VT, cardiac mortality/VT, and all-cause mortality/VT. Studies with ≥100 patients and ≥10 events were included. Results: Fifteen studies including 7218 patients (average age 27.5 years) were analyzed. Risk factors for VT included older age (per 1 year, odds ratio [OR]: 1.039; 95% confidence interval [CI]: 1.025-1.053), older age at corrective surgery (per 1 year, OR: 1.034; CI: 1.017-1.051), previous palliative shunt (OR: 3.063; CI: 1.525-6.151), number of thoracotomies (OR: 1.416; CI: 1.249-1.604), longer QRS duration (per 1 ms, OR: 1.031; CI: 1.008-1.055), and at least moderate right-ventricular dysfunction (OR: 2.160; CI_ 1.311-3.560). Additional risk factors for cardiac death/VT were previous ventriculotomy (OR: 2.269; CI: 1.226-4.198), lower left-ventricular ejection fraction (per 1%, OR: 1.049; CI: 1.029-1.071), and higher right-ventricular end diastolic volume (per 1 mL/m², OR: 1.009; CI: 1.002-1.016). Supraventricular tachycardia/atrial fibrillation was an additional risk factor for all-cause mortality/VT (OR: 1.939; CI: 1.088-3.457). Conclusions: The study highlights the importance of preservation of biventricular systolic function on late outcomes. Ventricular function appears to have a greater impact on outcomes than the severity of pulmonary regurgitation alone in this patient population.