MiscellaneousUsefulness of Right-to-Left Shunting and Poor Exercise Gas Exchange for Predicting Prognosis in Patients With Pulmonary Arterial Hypertension
Section snippets
Methods
We prospectively enrolled 103 patients with idiopathic PAH (IPAH), familial PAH, and associated PAH (APAH), as defined by currently accepted diagnostic World Health Organization group I criteria9 into a long-term, noninvasive outcome study evaluating serial CPET measurements. All patients underwent diagnostic right heart catheterization with measurements of the right atrial, right ventricular, pulmonary arterial, and pulmonary capillary wedge pressure and cardiac output. Patients with disorders
Results
All patients survived at least to their second CPET. The patients were followed up for a mean of 4.7 years after their first CPET. The baseline patient demographics, CPET findings, and invasive hemodynamics are listed in Table 1. Our population was mostly women, consistent with previously reported cohorts from our institution.2 The baseline peak oxygen uptake and ratio of ventilation to carbon dioxide output at the anaerobic threshold was 0.79 ± 0.26 L/min and 49 ± 13 (normal <34),
Discussion
Although previous studies have demonstrated the prognostic utility of CPET in patients with PAH,5 our study is the first to evaluate the prognostic value of repeated CPET measurements. In addition, our study is the first to show that an exercise-induced right-to-left shunt predicts a poorer outcome in patients with PAH. Moreover, we have shown that, beyond the traditional measurements of exercise capacity and ventilatory efficiency, assessing shunt status is useful for predicting the outcome in
Acknowledgment
We are grateful to Joy Beckmann, RN, and Daisy Camanga, RN, for their tireless efforts in treating patients and to Chase Kissling, BS, Kevin Chang, BS, and Daniel Dumitrescu, MD, for their help in database organization.
References (19)
- et al.
Diagnosis of pulmonary vascular limit to exercise by cardiopulmonary exercise testing
J Heart Lung Transplant
(2004) - et al.
Atrial septostomy as palliative therapy for refractory primary pulmonary hypertension
Am J Cardiol
(1983) - et al.
Updated clinical classification of pulmonary hypertension
J Am Coll Cardiol
(2009) - et al.
ACCF/AHA 2009 expert consensus document on pulmonary hypertension a report of the American College of Cardiology Foundation Task Force on Expert Consensus Documents and the American Heart Association developed in collaboration with the American College of Chest Physicians; American Thoracic Society, Inc.; and the Pulmonary Hypertension Association
J Am Coll Cardiol
(2009) - et al.
Reproducibility of cardiopulmonary exercise measurements in patients with pulmonary arterial hypertension
Chest
(2004) - et al.
Validity of ear oximetry in clinical exercise testing
Chest
(1987) - et al.
Cardiopulmonary exercise testing and six-minute walk correlations in pulmonary arterial hypertension
Am J Cardiol
(2006) - et al.
Exercise pathophysiology in patients with primary pulmonary hypertension
Circulation
(2001) - et al.
Clinical efficacy and survival with first-line inhaled iloprost therapy in patients with idiopathic pulmonary arterial hypertension
Eur Heart J
(2005)
Cited by (57)
Gas Exchange and Ventilatory Efficiency During Exercise in Pulmonary Vascular Diseases
2020, Archivos de BronconeumologiaPulmonary Hypertension and Exercise
2019, Clinics in Chest MedicineRelating exercise-induced desaturation and gas-exchange in pulmonary artery hypertension
2019, Respiratory Physiology and NeurobiologyChallenges in pulmonary hypertension
2017, Revista Colombiana de CardiologiaClinical usefulness of end-tidal CO<inf>2</inf> profiles during incremental exercise in patients with chronic thromboembolic pulmonary hypertension
2016, Respiratory MedicineCitation Excerpt :Very interestingly, decreased PetCO2 during exercise is associated with the blunted cardiac output response to exercise in patients with heart failure [12]. In addition, a sudden and abrupt decrease of PetCO2 may indicate exercise-induced shunt (EIS) [13], which is a finding that has prognostic implications in PAH [14]. Despite sharing some pathophysiological mechanisms [15], patients with chronic thromboembolic pulmonary hypertension (CTEPH) are more likely to have proximal vascular obstructive lesions, which may lead to poorer right ventricle–pulmonary vascular coupling [16–18] and worse gas exchange abnormalities compared to idiopathic PAH (IPAH).
Predictive value of NT-proBNP combined with exercise capacity variables in pulmonary artery disease: Insights from a Spanish cohort
2015, International Journal of Cardiology
This research was supported by grant 1 K23 RR17596-01 from the National Institutes of Health, Bethesda, Maryland, grant M01-RR00425 from the National Institutes of Health/Harbor-UCLA General Clinical Research Center, Torrence, California, and Beginning Grant-in-Aid 0160126Y from the American Heart Association, Dallas, Texas.