The association of right ventricular-pulmonary arterial coupling and pulmonary vascular resistance in adult patients with uncorrected atrial septal defect.

BACKGROUND

Atrial septal defects (ASD) are the most common type of adult congenital heart disease (ACHD) associated with a high risk developing of pulmonary arterial hypertension (PAH). ASD closure is not recommended in patients with PAH and Pulmonary Vascular Resistance (PVR) ≥ 5 Wood Unit (WU). Noninvasive methods have been proposed to measure PVR; however, their accuracy remains low. Right Ventricle (RV) - Pulmonary Artery (PA) coupling is defined as the ability of the RV to adapt to high-resistance conditions. Tricuspid Annular Plane Systolic Excursion (TAPSE)/estimated pulmonary artery systolic pressure (ePASP) calculation using echocardiography is a noninvasive technique that has been proposed as a surrogate equation to evaluate RV-PA coupling. Currently, no research has demonstrated a relationship between RV-PA coupling and PVR in patients with ASD.

METHODS

The study participants were consecutive eligible patients with ASD who underwent right heart catheterization (RHC) and echocardiography at Hasan Sadikin General Hospital, Bandung. Both the procedures were performed on the same day. RV-PA Coupling, defined as TAPSE/ePASP > 0.31, was assessed using echocardiography. The PVR was calculated during RHC using the indirect Fick method.

RESULTS

There were 58 patients with ASD underwent RHC and echocardiography. Among them, 18 had RV/PA Coupling and 40 had RV/PA Uncoupling. The PVR values were significantly different between the two groups (p = 0.000). Correlation test between TAPSE/ePASP with PVR showed moderate negative correlation (r= -0.502, p = 0.001). TAPSE/ePASP ≤ 0.34 is the cutoff point to predict PVR > 5 WU with sensitivity of 91.7% and specificity 63.6%.

CONCLUSION

This study showed a moderate negative correlation between TAPSE/ePASP and PVR. TAPSE/ePASP ≤ 0.34 could predict PVR > 5 WU with good sensitivity.