Cardiac Morphometry on Computed Tomography and Exacerbation Reduction with b-Blocker Therapy in Chronic Obstructive Pulmonary Disease

To adjust for the lower propensity to prescribe ß-blockers in COPD, and higher propensity in coronary artery disease and congestive heart failure, we created a logistic regression model with ß-blocker use as the dependent variable, and age, sex, race, body mass index, coronary artery disease and congestive heart failure, and COPD severity by Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage (2-4) as independent variables. Because we did not have controls, we are unable to distinguish whether the lower LV size is relative or absolute, with the latter implying there might be additional mechanisms involved such as cachexia and apoptosis, with differential response to ß-blockers. A limitation is that CT scans were nonelectrocardiogram-gated noncontrast scans, and hence we were unable to estimate ventricular mass and end-diastolic or end-systolic volumes separately; however, by providing a global measure of cardiac chamber size that can be easily obtained on clinically available scans, high RV/LV ratio on CT is a potentially useful and easily measurable biomarker for patient selection before administration of ß-blockers in patients with COPD. ? University of Colorado Anschutz Medical Campus Aurora, Colorado Matthew J. Budoff, M.D. Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center Los Angeles, California Michael J. Cuttica, M.D. Northwestern University Feinberg School of Medicine Chicago, Illinois J. Michael Wells, M.D. University of Alabama at Birmingham Birmingham, Alabama RaUl San Jose Estepar, Ph.Dd George R. Washko, M.D., M.M.Scd Harvard Medical School Boston, Massachusetts *Co-first authors.