Abstract 9677: Therapeutic Improvements in Pulmonary Arterial Hypertension Are Related to Cardiopulmonary Function but Not Skeletal Muscle Oxygen Extraction

Autor: Steven Stroud, Michael Insel, Tushar Acharya, Franz Rischard
Rok vydání: 2021
Předmět:
Zdroj: Circulation. 144
ISSN: 1524-4539
0009-7322
Popis: Introduction: World Symposium Group 1 pulmonary arterial hypertension (PAH) patients have impaired function from both central oxygen delivery and skeletal muscle oxygen extraction. The effect of PH-directed therapy on skeletal muscle oxygen extraction is unknown. The aim of this study is to determine if therapy associated changes in muscle extraction parallel changes in cardiopulmonary function. Methods: Retrospective analysis was performed on twenty-nine PAH patients (24 female, mean age 54±11.4 years) receiving prostacyclin therapy (18 on monotherapy). Subjects underwent invasive cardiopulmonary exercise testing (iCPET) for treatment response evaluation followed by repeat surveillance iCPET with mean follow-up of 10.4±5.2 months. Skeletal muscle oxygen extraction was quantified by arterio-venous difference indexed to hemoglobin (Ca-vO 2 /Hgb) and systemic oxygen extraction ratio (SER) (Ca-vO 2 /CaO 2 ). Central oxygen delivery (DO 2 ) was calculated as peak cardiac output X CaO2 at peak exercise. Functional capacity was semi-quantified by six-minute walk test (6MWT) distances between assessments (n=20). Subjects were stratified into two groups: those with improvement (n=10) vs unimproved (n=19) in currently accepted ERS/COMPERA score ( Figure ). Results: Improvements in ERS/COMPERA score were related to DO 2 (318.3±273.1 vs -38.3±684.9 mL/min, P=.016 ) and PVR (-4.8±3.0 vs -0.6±3.2 WU, P=.002 ) (Figure A & B). However, there was not a detectible difference between assessments in Ca-vO 2 /hgb (-0.01±0.14 vs 0.00±0.27 mL/g, P=.573 ), SER (-0.01±0.10 vs 0.00±0.20, P=.573 ), or 6MWT (7 improved, 13 unimproved) (77±115 vs 25±104 meters, P=.877 ) ( Figure C & D ). Conclusions: Although PH-directed therapy improves both PVR and oxygen delivery, its effects on skeletal muscle extraction are questionable. Clinicians should consider that oxygen extraction may influence functional capacity when evaluating therapeutic improvement.
Databáze: OpenAIRE