Abstract
BACKGROUND: The increasing number of adult congenital heart disease (ACHD) patients, especially in low- and middle-income countries (LMICs), necessitates effective management methods. The Qp/Qs or flow ratio (FR) is crucial for this purpose because one of the indications for closure is a significant shunt. This study compares the utility of the transthoracic echocardiography (TTE)-derived flow ratio (FR(echo)) with that of the right heart catheterization (RHC)-derived flow ratio (FR(rhc)) to guide clinical decisions in resource-limited settings. MATERIALS AND METHODS: This cross-sectional study in Bandung, Indonesia, included 36 patients with uncorrected acyanotic ACHD who underwent both RHC and TTE on the same day. FR(echo) was calculated using stroke volumes of the respective ventricles derived from Doppler measurements, and FR(rhc) was measured using indirect Fick's method. RESULTS: Of the 36 patients, 80.6% were female, with a median age of 31 (18-65) years. The majority had secundum atrial septal defects (61.1%). The mean FR(echo) was 2.8 ± 1.5 and the median FR(rhc) was 1.69 (0.46-3.89). FR(echo) showed a significant positive correlation with FR(rhc) (ρ = 0.656, p < 0.001). Bland‒Altman analysis revealed a mean difference of 1 (-1.4-3.3). Subgroup analysis of patients with a FRrhc shunt < 1 showed a mean difference of 0.7 (-1-2.3). CONCLUSION: TTE-derived FR(echo) tends to overestimate FR compared to FR(rhc). FR(echo) should not be used as a surrogate for FR(rhc) in this population.