Correlation between cardiopulmonary exercise test variables and health-related quality of life among children with idiopathic or heritable pulmonary hypertension

Introduction

Pulmonary hypertension (PH) is a progressive disease characterized by elevation of pulmonary vascular resistance, ultimately leading to right ventricular failure and premature death. Traditionally, physical activity has been restricted for these patients, but there's a current trend to customize exercise programs based on CPET results.

Quality of life (QoL) now stands as a determinant “patient-related outcome” and is frequently used as a secondary endpoint in cardiovascular clinical trials. Little is known about the relation between CPET data and QoL in patients with idiopathic or heritable pulmonary hypertension in children.

Objective

The primary objective was to correlate self and parent-reported QoL with CPET variables, while the secondary objective was to correlate QoL and CPET variables with other clinical, biological, echocardiographic or hemodynamic parameters.

Methods

The study was conducted retrospectively at Marseille University Hospital, involving nine children (7 heritable PH, 2 idiopathic PH) who underwent CPET and completed QoL questionnaires.

Following data were extracted from clinical files for analysis: peak of VO2, ventilatory anaerobic threshold (AT), VE/VCO2 slope and ST-wave changes on CPET; pediatric quality of life (PedsQL 4.0TM) on QoL questionnaires; age and years since diagnosis, last available RV to LV pressure ratio, mPA pressure and indexed pulmonary resistance, RV ejection fraction, NT-proBNP level.

Expected results

Characteristics at time of diagnosis are summarized in Table 1. Results are summarized in Table 2.

CPET parameters are very abnormal in this population and might correlate with QoL, but also with other clinical and hemodynamic severity indexes.

It is important to mention that all CPET were performed in stable conditions (once optimal treatment was achieved) and were all uneventful.

Perspectives

To our opinion, CPET is an important and useful tool to assess QoL but also to guide clinical management, and elaborate appropriate rehabilitation programs. This small study might serve as a pilot study before a large multicentric study.