Right Ventricular Stroke Work Effective Biomarker in Pediatric PAH

Right ventricle stroke work indexed by ejection fraction and body surface area (RVSW_EF) demonstrated a relationship with clinical worsening in pediatric patients with pulmonary arterial hypertension (PAH) and may be a useful indicator of poorer clinical prognosis, according to the results of a retrospective study published in Pulmonary Circulation.

The 5-year survival rates can be poor in patients with severe PAH, but the course of the disease is variable and generally unpredictable. In some cases, lung or heart-lung transplantation may be the only viable option. However, because there are significant risks associated with transplantation, it is crucial to determine which patients are most likely to require a transplant. Development of biomarkers that can more accurately predict the course of the disease is of great importance.

Weiguang Yang, PhD, of the Department of Pediatrics (Cardiology) at Stanford University in California, and colleagues devised a novel way of assessing RVSW as a potential biomarker for clinical worsening in pediatric patients with PAH. The investigators quantified RVSW directly from pressure-volume (P-V) loops using computational modeling that included clinical data in conjunction with clinical outcomes.

The researchers included 17 patients (12 with idiopathic PAH and 5 with PAH associated with congenital heart disease; average age, 9.4 years) who had undergone right heart catheterization and magnetic resonance imaging at Lucile Packard Children’s Hospital Stanford from July 2006 to August 2015.

Of these patients, 9 remained clinically stable during the course of the study. However, the condition of the other 8 patients deteriorated: 2 died, 2 were recommended for a heart/lung transplant, and 3 received a transplant; 1 patient had a poor hemodynamic response to intravenous prostanoids. During the course of the study, RVSW_EF values of patients who were clinically stable moved downward or remained lower compared with those of patients whose condition worsened. In contrast, in patients whose conditions deteriorated, RVSW_EF values trended upward.

The investigators noted that RVSW_EF surpassed pulmonary vascular resistance index, the ratio of pulmonary to systemic resistance, and ejection fraction for predicting clinical worsening as determined by receiver operation characteristic analysis. Limitations included the small patient population and the retrospective nature of the study.

Reference

Yang W, Marsden AL, Ogawa MT, et al. Right ventricular stroke work correlates with outcomes in pediatric pulmonary arterial hypertension [published online May 16, 2018]. Pulm Circ. doi:10.1177/2045894018780534