Cardiac Catheterization and Hemodynamics in a Multicenter Cohort of Children with Pulmonary Hypertension

Abstract

Rationale: Hemodynamic assessments direct care among children with pulmonary hypertension, yet the use of cardiac catheterization is highly variable, which could impact patient care and research. Objectives: We analyzed hemodynamic findings from right heart catheterization (RHC) and left heart catheterization and acute vasodilator testing (AVT) and the safety of catheterization in children with World Symposium on Pulmonary Hypertension (WSPH) group 1 and 3 subtypes in a large multicenter North American cohort. Methods: Of 1,475 children enrolled in the Pediatric Pulmonary Hypertension Network Registry (2014-2020), there were 1,383 group 1 and 3 patients, of whom 671 (48.5%) underwent RHC at diagnosis and were included for analysis. Results: Compared with those without diagnostic RHC, these children were older, less likely to be an infant or preterm, more often female, treated with targeted pulmonary hypertension medications at diagnosis, and had advanced World Health Organization functional class. Catheterization was performed without a difference in complication rates between WSPH groups. Pulmonary capillary wedge pressure was well correlated with left ventricular end-diastolic pressure and left atrial pressures. Results of AVT using three different methods were comparable; positive AVT results were observed in 8.0-11.8% of subjects, did not differ between WSPH groups 1 and 3, and were not associated with freedom from the composite endpoint of lung transplantation or death during follow-up. Conclusions: In a large pediatric pulmonary hypertension cohort, diagnostic RHC with or without left heart catheterization in WSPH group 1 and 3 patients was performed safely at experienced pediatric pulmonary hypertension centers. Hemodynamic differences were noted between group 1 and 3 subjects. Higher mean pulmonary arterial pressure and mean pulmonary arterial pressure/mean systemic arterial pressure ratio were associated with a higher risk of death/transplantation. Findings suggest overall safety and potential value of RHC as a standard diagnostic approach to guide pulmonary hypertension management in children.

Keywords: cardiac catheterization; hemodynamics; pediatrics; pulmonary hypertension; vasoreactivity testing.

Figure 1.

Enrollees in the Pediatric Pulmonary Hypertension Network Registry were included in this report as illustrated. AVT = acute vasodilator testing; LHC = left heart catheterization; PPHNet = Pediatric Pulmonary Hypertension Network; Qp:Qs = pulmonary-to-systemic flow ratio; RHC = right heart catheterization; WSPH = World Symposium on Pulmonary Hypertension.

Figure 2.

(A) Pulmonary capillary wedge pressure (PCWP) is positively correlated with left atrial pressure. Hemodynamic data are from the baseline catheterization performed at pulmonary hypertension diagnosis. (B) PCWP is positively correlated with left ventricular end-diastolic pressure (LVEDp) when LVEDp is more than 5 mm Hg. Hemodynamic data are from the baseline catheterization performed at pulmonary hypertension diagnosis. LAP = left atrial pressure; WSPH = World Symposium on Pulmonary Hypertension.

Figure 3.

(A) Transplantation-free survival estimates by baseline hemodynamics from the catheterization performed at the time of pulmonary hypertension diagnosis. Mean pulmonary artery pressure (PAPm) (n = 634) and PAPm/mean systemic arterial pressure (SAPm) ratio (n = 467) are associated with risk of the composite of death/lung transplantation (P ⩽ 0.001). Patients in the highest tertile have the highest hazard of death/lung transplantation, and patients in the middle tertile have significantly higher risk compared with those in the lowest tertile. The figures are truncated at 15 years; some follow-up extended past 20 years, but no events occurred after 15 years. (B) Survival estimates by baseline hemodynamics from the catheterization performed at the time of pulmonary hypertension diagnosis, according to competing-risks analysis. PAPm (n = 634, P = 0.029) and PAPm/SAPm ratio (n = 467, P = 0.001) are associated with mortality. Patients in the highest tertile for PAPm (>50 mm Hg) have a higher hazard of death than those with PAPm in the first tertile, but patients in the middle tertile cannot be shown to differ from either adjacent tertile. For PAPm/SAPm, patients in the highest tertile have the highest hazard of death/lung transplantation. The figures are truncated at 15 years; some follow-up extended past 20 years, but no events occurred after 15 years. Cath =  catheterization.