Echocardiographic Right Ventricular Wall Tension Indicates Disease Severity in Children with Pulmonary Arterial Hypertension

Background: Recently, simplified echocardiographic RV wall tension (RVWTe), defined as the product of tricuspid regurgitation (TR) pressure gradient (TRPG) and end-diastolic base-to-apex length, was identified as an echocardiographic predictor of altered invasive RV hemodynamics in adults with PH. RVWTe was increased early in the disease process and associated with all-cause mortality at ∼5-year follow-up, while TAPSE, RV fractional area change, TRPG (calculated from TR velocity), and TAPSE/TR velocity ratio were not.

Method: In the current prospective study, 17 children (age range: 4.0–17.6 years) with pulmonary arterial hypertension (PAH) underwent transthoracic echocardiography, cardiac magnetic resonance (CMR), and combined right-left heart catheterization, to calculate noninvasive and combined noninvasive/invasive EPPVDN PH risk scores. We correlated RVWTe with outcome relevant imaging variables and with the EPPVDN PH risk scores.

Results: We found the echocardiographic RVWTe to be abnormally increased in pediatric PAH (median: 4,867 [IQR: 4,100–7,768], range: 2,265–11,985 mm Hg × mm; n = 17) versus the adult cutoff for increased mortality with secondary TR (3,300 mm Hg × mm) and to correlate with clinically relevant CMR-derived variables: RV/LV end-systolic volume ratio (rho = 0.71, p = 0.002), RV global longitudinal strain (r = 0.68, p = 0.003), RV/LV end-diastolic volume ratio (rho = 0.69, p = 0.003) and RV ejection fraction (r = −0.53, p = 0.034), and with echocardiographic measures of RV contractility, dilation and interventricular septal shift: RV global-longitudinal strain (rho = 0.87, p < 0.001), LV end-systolic eccentricity index (rho = 0.8, p < 0.001), RV/LV end-systolic diameter ratio (rho = 0.87, p < 0.001) and RV free wall longitudinal strain (r = 0.65, p = 0.005). Further, RVWTe correlated very strongly with the EPPVDN risk scores (rho > 0.8, p < 0.001).

Conclusion: This exploratory study is the first to demonstrate increased RVWTe in children with PAH and to validate the RVWTe by correlating RVWTe with CMR-derived variables known to prognosticate clinical outcomes. Most importantly, despite the small cohort, the simplified RVWTe correlates very strongly with the new EPPVDN PH risk score. Thus, RVWTe has the potential to become an easily applicable, prognostic echocardiographic marker of PH severity in pediatric PH patients with a reliable TRPG-Doppler measurement.

Publication History

Article published online:
28 January 2023