RA Conduit Phase Emptying May Predict Adverse Event Risk in Pediatric PAH

pulmonary hypertension PAH PH
pulmonary hypertension PAH PH
Right atrial conduit phase emptying may predict the risk for adverse clinical events in pediatric patients with pulmonary arterial hypertension.

Right atrial (RA) conduit phase emptying may predict the risk for adverse clinical events in pediatric patients with pulmonary arterial hypertension (PAH), according to study results published in the Journal of the American Society of Echocardiography.

Researchers conducted a single center prospective cohort analysis of 41 patients (median age, 11.9 years) with idiopathic or heritable PAH to examine the usefulness of RA fractional emptying indices in the prognosis of pediatric PAH. Patients were age- and sex-matched with control individuals in a 1:1 ratio and were all evaluated using echo- and electrocardiography. An adverse clinical event was defined as initiation of parenteral prostanoid therapy, PAH-related hospitalization, atrial septostomy, Potts shunt, lung transplant, or death.

Patients with PAH had decreased RA conduit fraction percent compared with control individuals (P <.0001). In patients with PAH, those with lower RA conduit fraction percent had higher right ventricular systolic and end diastolic pressure (r= -0.49; P =.019 and r= -0.52; P =.012, respectively) compared with patients with higher RA conduit fraction percent. RA conduit fraction percent (hazard ratio, 0.09; P <.001) and right ventricular systolic pressure percent of left ventricular systolic pressure (hazard ratio, 10.33; P =.001) were found to have high prognostic value to estimate the risk for adverse clinical events.

A total of 16 patients with PAH experienced an adverse clinical event during the follow-up period (median, 3.2 years). Patients with vs without a clinical event had greater RA area (P =.049), smaller RA fractional area change (P =.004), and smaller RA conduit fraction percent (P <.001) on echocardiogram.

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Study limitations included a modest size patient group, the inability to evaluate the effect of tricuspid regurgitation on RA emptying fraction, and the fact that most patients were not treatment-naive at time of enrollment. Researchers noted that the study results should be validated in larger and different patient populations.

Compared with controls, patients with PAH with a benign clinical course had a mild decrease in conduit emptying and patients with severe clinical course had worse conduit emptying.

“The combination of accuracy and ease of measurement could make RA [conduit fraction percent] a clinically useful, noninvasive biomarker of early right heart failure and risk of disease progression in pediatric PAH,” the researchers concluded.


Frank BS, Schafer M, Thomas TM, Haxel C, Ivy D, Jone P-N. Right atrial conduit phase emptying predicts risk of adverse events in pediatric pulmonary arterial hypertension [published online April 24, 2020]. J Am Soc Echocardiogr. doi:10.1016/j.echo.2020.02.015