1. Lower DLco% identifies exercise pulmonary hypertension in patients with parenchymal lung disease referred for dyspnea
- Author
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Richard H. Zou, Stephen Y. Chan, S. Mehdi Nouraie, Michael G. Risbano, and William D Wallace
- Subjects
Pulmonary and Respiratory Medicine ,Parenchymal lung disease ,lcsh:Diseases of the circulatory (Cardiovascular) system ,medicine.medical_specialty ,Hemodynamics ,030204 cardiovascular system & hematology ,hemodynamics ,03 medical and health sciences ,0302 clinical medicine ,DLCO ,pulmonary arterial hypertension ,Internal medicine ,Diffusing capacity ,medicine ,In patient ,interstitial lung disease ,lcsh:RC705-779 ,business.industry ,Vascular disease ,Interstitial lung disease ,food and beverages ,lcsh:Diseases of the respiratory system ,respiratory system ,medicine.disease ,Pulmonary hypertension ,3. Good health ,chronic obstructive lung disease (COPD) ,030228 respiratory system ,lcsh:RC666-701 ,Cardiology ,exercise pulmonary hypertension ,business ,Research Article - Abstract
Exercise pulmonary hypertension is an underappreciated form of physical limitation related to early pulmonary vascular disease. A low diffusing capacity of lungs for carbon monoxide (DLco) can be seen in patients with resting pulmonary hypertension as well as parenchymal lung disease. It remains unclear whether low DLco% identifies early pulmonary vascular disease. We hypothesize that a reduced DLco% differentiates the presence of exercise pulmonary hypertension in patients with parenchymal lung disease. Fifty-six patients referred for unexplained exertional dyspnea with pulmonary function tests within six months of hemodynamic testing underwent exercise right heart catheterization. Exclusion criteria included resting pulmonary arterial or venous hypertension. Receiver operator characteristic curve determined the optimal DLco% cutoffs based on the presence or absence of parenchymal lung disease. Twenty-one (37%) patients had parenchymal lung disease, most common manifesting as chronic obstructive lung disease or interstitial lung disease. In patients with parenchymal lung disease, a DLco of 46% demonstrated 100% sensitivity and 73% specificity for detecting exercise pulmonary hypertension. In patients without parenchymal lung disease, a DLco of 73% demonstrated 58% sensitivity and 94% specificity for detecting exercise pulmonary hypertension. In both cohorts, DLco% below the optimum cutoffs were associated with higher peak mean pulmonary arterial pressure and peak total pulmonary resistance consistent with the hemodynamic definition of exercise pulmonary hypertension. Patients with a DLco
- Published
- 2020