Cardiac magnetic resonance predictors of ventricular arrhythmias inducibility before pulmonary valve replacement in patients with Tetralogy of Fallot.

Ventricular arrhythmias and sudden death are recognized complications of tetralogy of Fallot (TOF). Electrophysiological study (EPS) is increasingly performed prior to pulmonary valve replacement (PVR) in these patients to evaluate and treat the arrhythmic substrate. We aimed to assess the value of cardiac magnetic resonance (CMR) to refine pre-operative risk stratification in this population. A prospective multicenter study was conducted to systematically assess EPS in patients with TOF referred for PVR from January 2020 to December 2021 in 5 tertiary centers in France. CMR parameters including right ventricular (RV) - left ventricular (LV) volumes, function, and as well as pulmonary regurgitant fraction and pulmonary annulus diameter were assessed. A positive EPS was defined as inducibility of a sustained ventricular arrhythmia (VA). A total of 120 patients were enrolled. Among the 108 (90.0%) patients who had a CMR prior to EPS, 24 (22.2%) had a VA inducible. Clinical characteristics of patients associated with EPS results are presented in table1. Concerning CMR variables, mean RV end-diastolic volume index was 157 ± 39 ml and was not statistically different in patients with positive vs. negative EPS (164 ± 49 vs. 155 ± 35, p = 0.395). However, a RV/LV end-diastolic volume index ratio > 2.4 was significantly associated with a higher likelihood of inducibility (OR 3.10, 95%CI 1.14–8.74, p = 0.040). Mean RV end-systolic volume index tended to be upper in patient with positive EPS (101 ± 35 vs. 86 ± 26, p = 0.072). The RV ejection fraction (RVEF) measured on CMR also tended to be slightly lower in patients with positive EPS (40 ± 7 vs. 43 ± 9, p = 0.069) unlike the LV ejection fraction (LVEF) (p = 0.600). Mean pulmonary annulus diameter were significantly associated with positive EPS (31 ± 8 vs. 26 ± 7, OR 1.10 [1.02–1.18], p = 0.012) and also with a cut-off > 28 mm (60.9% vs 34.4%, OR 2.92 [1.10–8.11] p = 0.047). Others non-CMR factors associated with inducible VA are presented in Table 1. In patients with TOF prior to PVR, RV/LV end-diastolic volume index ratio and pulmonary annulus diameter are associated with ventricular arrhythmia inducibility during EPS. CMR parameters, in combination with other clinical factors, may be useful to improve pre-operative risk stratification. [ABSTRACT FROM AUTHOR]