# Utilization of the flow ratio measured by echocardiography (FRecho) compared to the flow ratio by right heart catheterization (FRrhc) for detecting Eisenmenger syndrome in uncorrected acyanotic adult congenital heart disease (ACHD)

## TL;DR

This study compares two methods for measuring blood flow ratios in adult congenital heart disease patients and finds that one method overestimates the flow ratio compared to the other.

## Contribution

The study evaluates the reliability of TTE-derived flow ratio as a substitute for RHC-derived flow ratio in ACHD patients.

## Key findings

- FRecho significantly correlates with FRrhc but tends to overestimate the flow ratio.
- Bland-Altman analysis shows a mean difference of 1 between FRecho and FRrhc.
- FRecho should not replace FRrhc for clinical decision-making in this population.

## Abstract

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 (FRecho) with that of the right heart catheterization (RHC)-derived flow ratio (FRrhc) to guide clinical decisions in resource-limited settings.

This cross-sectional study in Bandung, Indonesia, included 36 patients with uncorrected acyanotic ACHD who underwent both RHC and TTE on the same day. FRecho was calculated using stroke volumes of the respective ventricles derived from Doppler measurements, and FRrhc was measured using indirect Fick’s method.

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 FRecho was 2.8 ± 1.5 and the median FRrhc was 1.69 (0.46–3.89). FRecho showed a significant positive correlation with FRrhc (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).

TTE-derived FRecho tends to overestimate FR compared to FRrhc. FRecho should not be used as a surrogate for FRrhc in this population.