Parameter Trio Can Help Predict Prognosis in Children With PAH

A trio of parameters with potential to help risk stratify pediatric patients with pulmonary arterial hypertension (PAH) have been identified by the researchers of a new study published in Journal of the American Heart Association. PAH, the investigators wrote, is associated with high morbidity and mortality in children.

The simple risk stratification score can be determined bedside without the need for a computer, explained the researchers. Although they note that their risk combination model needs validation, the group argues that these insights should guide recommendations for risk stratification and management of these patients.

“A major challenge to treating physicians is the lack of robust risk stratification tools, allowing clinicians to guide therapy and direct high-risk patients to parenteral prostanoid therapy and consideration of lung transplantation,” wrote the researchers. “While noninvasive assessment tools exist, transthoracic echocardiography remains the most important modality in the routine regular assessment of patients, including 6-minute walk test distance and natriuretic peptide levels.”

The researchers included 63 patients in their study, all of whom had PAH and a biventricular cardiac anatomy without relevant shunt lesions. All patients underwent a standardized transthoracic echocardiography and came from a single center in London between 2005 and 2013. Over a median of 4.1 years of follow-up, 17 patients died and 4 underwent lung transplantation.

Results show that a combination of right atrial (RA) area, left ventricular (LV) eccentricity index, and tricuspid annual plane excursion—a group of widely available parameters—could serve as a simple score to determine prognosis. Analysis showed the 3 parameters were all independent predictors of mortality.

The researchers highlighted that the combination offers information on different physiological consequences of PAH. For example, RA distention may be a result of various processes, making it a composite biomarker, and LV eccentricity index is a quantitative description of interventricular septal deviation.

“Perhaps surprisingly, however, we found RA area and LV eccentricity index to have superior discriminative ability and to be more robust compared with tricuspid annular plane excursion [TAPSE], especially for the combined end point, even when TAPSE was adjusted for children’s age in our cohort,” detailed the researchers. “When mortality alone was considered as an end point, however, TAPSE emerged as an independent predictor of outcome and should thus be considered as an adjunct in the risk stratification process.”

Using a combination of the parameters, the researchers created a risk prediction model following a flow chart design, which differentiated patients by prognosis. They note that the prediction model needs external validation.

The researchers also noted that strain measurements were not included in their analysis, with future research needed to determine their potential prognostic value.

Reference

Lammers AE, Marek J, Diller G-P, Haworth SG, Moledina S. Prognostic value of transthoracic echocardiography in children with pulmonary arterial hypertension. J Am Heart Assoc. Published online March 21, 2023. doi:10.1161/JAHA.121.023118