@article {1433576,
	title = {Pruning of the Pulmonary Vasculature in Asthma. The Severe Asthma Research Program (SARP) Cohort},
	journal = {Am J Respir Crit Care Med},
	volume = {198},
	number = {1},
	year = {2018},
	month = {2018 Jul 01},
	pages = {39-50},
	abstract = {RATIONALE: Loss of the peripheral pulmonary vasculature, termed vascular pruning, is associated with disease severity in patients with chronic obstructive pulmonary disease.

OBJECTIVES: To determine if pulmonary vascular pruning is associated with asthma severity and exacerbations.

METHODS: We measured the total pulmonary blood vessel volume (TBV) and the blood vessel volume of vessels less than 5 mm2 in cross-sectional area (BV5) and of vessels less than 10 mm2 (BV10) in cross-sectional area on noncontrast computed tomographic scans of participants from the Severe Asthma Research Program. Lower values of the BV5 to TBV ratio (BV5/TBV) and the BV10 to TBV ratio (BV10/TBV) represented vascular pruning (loss of the peripheral pulmonary vasculature).

MEASUREMENTS AND MAIN RESULTS: Compared with healthy control subjects, patients with severe asthma had more pulmonary vascular pruning. Among those with asthma, those with poor asthma control had more pruning than those with well-controlled disease. Pruning of the pulmonary vasculature was also associated with lower percent predicted FEV1 and FVC, greater peripheral and sputum eosinophilia, and higher BAL serum amyloid A/lipoxin A4 ratio but not with low-attenuation area or with sputum neutrophilia. Compared with individuals with less pruning, individuals with the most vascular pruning had 150\% greater odds of reporting an asthma exacerbation (odds ratio, 2.50; confidence interval, 1.05-5.98; P = 0.039 for BV10/TBV) and reported 45\% more asthma exacerbations during follow-up (incidence rate ratio, 1.45; confidence interval, 1.02-2.06; P = 0.036 for BV10/TBV).

CONCLUSIONS: Pruning of the peripheral pulmonary vasculature is associated with asthma severity, control, and exacerbations, and with lung function and eosinophilia.},
	keywords = {Adult, Aged, Aged, 80 and over, Asthma, Blood Vessels, Cohort Studies, Cross-Sectional Studies, Disease Progression, Female, Forced Expiratory Volume, Humans, Lung, Male, Middle Aged, Severity of Illness Index},
	issn = {1535-4970},
	doi = {10.1164/rccm.201712-2426OC},
	author = {Ash, Samuel Y and Rahaghi, Farbod N and Come, Carolyn E and Ross, James C and Colon, Alysha G and Cardet-Guisasola, Juan Carlos and Dunican, Eleanor M and Bleecker, Eugene R and Castro, Mario and Fahy, John V and Fain, Sean B and Gaston, Benjamin M and Hoffman, Eric A and Jarjour, Nizar N and Mauger, David T and Wenzel, Sally E and Levy, Bruce D and Estepar, Raul San Jose and Israel, Elliot and Washko, George R}
}