Global Longitudinal Strain: A Novel Predictor of Postoperative Outcomes in Children Undergoing Rheumatic Valve Surgery

Background: Valve surgery in patients with paediatric rheumatic heart disease is challenging, owing to the complexities involved in the anatomy and hemodynamics. Relying on left ventricular dimensions and ejection fraction (EF) is misleading as the ventricle continues to have a normal EF till the late stages. Early intervention in these patients might reduce long term morbidity, the need for re operation, and mortality. Strain imaging using speckle tracking and peak global longitudinal strain (GLS) have been studied in adult valve repairs and found to predict long term outcomes. Aim and Objectives: To study the utility of peak GLS measured in the preoperative period to study the immediate and short term postoperative outcomes. Materials and Methods: The study included all 19 children who underwent valve surgery for rheumatic heart disease over a 2 year study period. Peak GLS was recorded in the preoperative period, at discharge and at periodical intervals till one year. The immediate outcomes studied were the duration of intensive care unit (ICU) and hospital stay, average vasoactive inotrope score (VIS), duration of inotropes and medium term outcomes were LV function and GLS at one year. Results: A peak GLS value of ≤−15% was associated with longer post operative ventilation and inotrope requirement. Even though all these children had a normal EF of >60% in the preop assessment, post operative LV EF was low in all the patients. At baseline, the entire population had an average GLS of −13.96%, with the ≤−15 group at −12.91% and the >−15 group at −16.23%. Both groups showed improvement, but group B experienced the most significant change, from −16.23% to −22.16% (a 5.93 unit improvement), compared to Group A, where change was from −12.91% to −16% (a 3.09 unit improvement), and the entire population’s change from −13.96% to −17.96% (a 4 unit improvement). Thus, while all groups benefited, patients with initially higher GLS values demonstrated the greatest positive change, indicating a greater potential for recovery or benefit from the surgery. This translates to an approximate 36.5% improvement in the > −15% group, a 23.9% improvement in the ≤−15% group, and a 28.7% improvement in the entire population, indicating a greater relative benefit for patients with preoperative GLS >−15%. Conclusions: The current study draws attention to the importance of identifying early deterioration of LV function in pediatric rheumatic heart disease to reduce the longterm morbidity and mortality. A value of GLS <−15% has a positive correlation in predicting prolonged and multiple inotrope requirements, duration of ventilation and post operative LV dysfunction.