Is There a Role for Electrophysiological Studies for Risk Stratification in Asymptomatic Patients with Congenital Heart Disease Prior to Percutaneous Pulmonary Valve Implantation?

Background: Percutaneous pulmonary valve implantation (PPVI) is an established alternative to surgery for treating patients with failing of pulmonary valve conduits. Especially in patients with congenital heart defects (CHD), there is an increased risk of ventricular arrhythmias often arising from the right ventricular outflow tract. In contrast to the operative approach, an arrhythmogenic substrate may remain after PPVI and an ablation therapy may be inferred after stent implantation due to the limited access to the arrhythmogenic substrate. Additionally, the implanted stent valves themselves can trigger ventricular arrhythmias.

Method: We performed electrophysiological studies (EPS) for risk stratification in patients with CHD and increased risk of monomorphic VT undergoing invasive evaluation for PPVI. This retrospective study includes patients, who underwent EPS between 2018 and 2021 at two centers. The focus was primary on patients with the repaired tetralogy of Fallot (TOF), double outlet right ventricle (DORV) pulmonary atresia (PAT), or pulmonary stenosis (PS). The risk stratification was performed according to a standardized protocol with programmed chamber stimulation with and without isoproterenol infusion. In patients with inducible arrhythmias ablation of the arrhythmogenic substrate was performed.

Results: A total of 22 patients (mean age = 21,3 years [8.3–43.8 years, median = 16 years), mean weight of 58.2 kg (25.9–91 kg)) underwent EPS in the same setting as evaluation for PPVI: TOF, n = 15; DORV, n = 5; truncus arteriosus communis, n = 1; and Rastelli's operation, n = 1. Inducible arrhythmias: monomorphic VT in 6 patients (27%; TOF: n = 4, DORV: n = 2), ventricular bigeminy with pulse deficit in 1 patient (Rastelli's procedure), typical atrial flutter in 1 patient (TOF) and in 1 patient (TOF) ventricular fibrillation was easily inducible so that an ICD was implanted. Overall, 7/22 (31%) patients underwent a second EPS with successful ablation of the arrhythmogenic substrate before PPVI. We performed isthmus ablation in one patient and PVC ablation in the other patient. In five patients with inducible monomorphic VT, the ablation site was in the right ventricular out flow tract, the other patient refused EPS.

Conclusion: EPS for risk stratification prior to PPVI identified a significant number of asymptomatic patients with a higher risk for malignant ventricular tachyarrhythmias. In addition, it allows ablation therapy before stent placement, especially in areas not accessible afterward. It remains to be discussed whether there are more patient groups with CHD who could benefit from risk stratification before PPVI.

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Artikel online veröffentlicht:
12. Februar 2022