B79-12 Congestive Heart Failure Is an Interstitial Lung Disease Mimic for Restrictive Pulmonary Function Tests

Previous research has shown correlations between increased lung congestion from heart failure and restrictive ventilation and reduced diffusing capacity of the lungs for carbon monoxide (DLCO). We hypothesized that Congestive Heart Failure (CHF) is an underrecognized cause of restrictive physiology. The goal of this study is to evaluate the frequency of CHF as a cause of restrictive physiology on pulmonary function tests (PFTs). This study is a retrospective observational study within the veteran population of a tertiary care center. PFTs of patients were first screened for a restrictive patten based on total lung capacity. All patients with restriction who had both a computerized tomography (CT) of the chest and an echocardiogram obtained within one year of the PFTs were included in the study. CT was reviewed for evidence of ILD. Echocardiograms were reviewed for systolic dysfunction, diastolic dysfunction, hypokinesis, and left atrial enlargement. This abstract covers the first cohort with available data. 38 cases were available for review. 13 (34%) had ILD. 19 (50%) had HFrEF and/or diastolic dysfunction. There was overlap: 8/13 of the ILD patients (61.5%) had concomitant HFrEF and/or diastolic dysfunction. When evidence for cardiac dysfunction was broadened to include left atrial enlargement or hypokinesis (without definitive LV dysfunction), a total of 25 patients (65.7%) had a possible cardiac contribution to restriction. Restrictive physiology often leads to a search for ILD. In our study, there was evidence for concomitant CHF in 61.5% of our ILD patients and of CHF alone in 57.8% of the patients without ILD. The limitation of this study is that it was performed at a VA hospital. Most patients were older men; the numbers would change with a more balanced population. The clinical messages are nevertheless clear: 1) CHF is a common cause of restrictive physiology and should be actively considered in the differential diagnosis. 2) CHF is common even when ILD is present. Whereas CHF is usually more amenable to treatment than ILD, these conclusions have clinical relevance. The finding of restriction on PFTs should prompt consideration both of intrinsic parenchymal disease and of cardiomyopathy.