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Hueper K, Vogel-Claussen J, Parikh MA, Austin JHM, Bluemke DA, Carr J, Choi J, Goldstein TA, Gomes AS, Hoffman EA, Kawut SM, Lima J, Michos ED, Post WS, Po MJ, Prince MR, Liu K, Rabinowitz D, Skrok J, Smith BM, Watson K, Yin Y, Zambeli-Ljepovic AM, Barr RG. Pulmonary Microvascular Blood Flow in Mild Chronic Obstructive Pulmonary Disease and Emphysema. The MESA COPD Study. Am J Respir Crit Care Med 2015; 192:570-80. [PMID: 26067761 DOI: 10.1164/rccm.201411-2120oc] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Smoking-related microvascular loss causes end-organ damage in the kidneys, heart, and brain. Basic research suggests a similar process in the lungs, but no large studies have assessed pulmonary microvascular blood flow (PMBF) in early chronic lung disease. OBJECTIVES To investigate whether PMBF is reduced in mild as well as more severe chronic obstructive pulmonary disease (COPD) and emphysema. METHODS PMBF was measured using gadolinium-enhanced magnetic resonance imaging (MRI) among smokers with COPD and control subjects age 50 to 79 years without clinical cardiovascular disease. COPD severity was defined by standard criteria. Emphysema on computed tomography (CT) was defined by the percentage of lung regions below -950 Hounsfield units (-950 HU) and by radiologists using a standard protocol. We adjusted for potential confounders, including smoking, oxygenation, and left ventricular cardiac output. MEASUREMENTS AND MAIN RESULTS Among 144 participants, PMBF was reduced by 30% in mild COPD, by 29% in moderate COPD, and by 52% in severe COPD (all P < 0.01 vs. control subjects). PMBF was reduced with greater percentage emphysema-950HU and radiologist-defined emphysema, particularly panlobular and centrilobular emphysema (all P ≤ 0.01). Registration of MRI and CT images revealed that PMBF was reduced in mild COPD in both nonemphysematous and emphysematous lung regions. Associations for PMBF were independent of measures of small airways disease on CT and gas trapping largely because emphysema and small airways disease occurred in different smokers. CONCLUSIONS PMBF was reduced in mild COPD, including in regions of lung without frank emphysema, and may represent a distinct pathological process from small airways disease. PMBF may provide an imaging biomarker for therapeutic strategies targeting the pulmonary microvasculature.
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Affiliation(s)
- Katja Hueper
- 1 Department of Radiology and.,2 Department of Radiology and Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Jens Vogel-Claussen
- 1 Department of Radiology and.,2 Department of Radiology and Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | | | | | - David A Bluemke
- 5 Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, Maryland
| | | | - Jiwoong Choi
- 7 Department of Radiology.,8 IIHR-Hydroscience & Engineering
| | - Thomas A Goldstein
- 9 Department of Biomedical Engineering, Stanford University, Stanford, California
| | | | - Eric A Hoffman
- 7 Department of Radiology.,11 Department of Medicine, and.,12 Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa
| | - Steven M Kawut
- 13 Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Joao Lima
- 1 Department of Radiology and.,14 Department of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Erin D Michos
- 14 Department of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Wendy S Post
- 14 Department of Medicine, Johns Hopkins University, Baltimore, Maryland
| | | | | | - Kiang Liu
- 16 Department of Biostatistics, Northwestern University, Chicago, Illinois
| | - Dan Rabinowitz
- 17 Department of Statistics, Columbia University, New York, New York; and
| | | | | | - Karol Watson
- 18 Department of Medicine, University of California at Los Angeles, Los Angeles, California
| | | | | | - R Graham Barr
- 3 Department of Medicine.,20 Department of Epidemiology, Columbia University Medical Center, New York, New York
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