Role of myocardial strain parameters in assessing indications for pulmonary valve replacement in children after tetralogy of Fallot repair: a cross-sectional study

BACKGROUND: Radical repair of tetralogy of Fallot significantly improves patients’ survival and quality of life. However, in the long-term postoperative period, most patients develop progressive pulmonary valve insufficiency. Pulmonary regurgitation gradually increases the volume load on the right ventricle, causing dilation, impaired systolic and diastolic function, and higher risk of arrhythmias and sudden cardiac death. In turn, pulmonary valve replacement decreases afterload and improves myocardial function. Nevertheless, the optimal timing of valve replacement in asymptomatic patients after tetralogy of Fallot repair remains unclear. AIM: This study aimed to evaluate myocardial strain parameters as potential criteria for determining the need for pulmonary valve replacement. METHODS: This single-center retrospective (medical record-based) cross-sectional study included data from patients treated at the departments of Cardiothoracic Surgery and Cardiology within the National Research Cardiac Surgery Center (Astana, Kazakhstan). Cardiac magnetic resonance imaging was performed between December 2011 and June 2020 in patients who had undergone radical tetralogy of Fallot repair. Because a threshold value of right ventricular end-diastolic volume (RVEDV) between 150 and 170 mL/m2 indicates a need for pulmonary valve replacement in asymptomatic patients, the sample was divided into two groups based on RVEDV: group 1, RVEDV 150 mL/m2, and group 2, RVEDV ≥150 mL/m2. The prognostic value of myocardial strain parameters in decision-making for timely pulmonary valve replacement was assessed. RESULTS: The study included 69 patients aged 3–18 years (11 ± 4 years) who had undergone radical tetralogy of Fallot repair. Circumferential strain in the basal anteroseptal segment of the left ventricle significantly differed between groups 1 (n = 52) and 2 (n = 17): −23.2 ± 5.8% vs −16.7 ± 8.4% (p = 0.003). Moreover, in the basal inferior segment of the left ventricle, significant differences were observed: −10.8 ± 5.2% in group 1 and −7.8 ± 6.8% in group 2 (p = 0.014). The right ventricular end-systolic volume in group 1 was approximately twice as low as in group 2: 56.9 ± 19.1 vs 103.9 ± 111.9 mL/m2 (p 0.001). CONCLUSION: The findings indicate the diagnostic value of myocardial strain parameters and their potential as additional criteria for evaluating indications for pulmonary valve replacement.