PURPOSE: Idiopathic Pulmonary Fibrosis (IPF) is frequently complicated by the development of Pulmonary Hypertension (PH) which adversely impacts patients’ functional status and survival. The best method for screening and detection of PH in IPF patients remains to be determined. We sought to investigate if measurement of the PA on CAT scan of the chest might correlate with the presence or severity of underlying PH.
METHODS: Retrospective review of patients with IPF who had CAT scans of the chest and right heart catheterizations (RHC) within a one year timeframe of one another. Measurements were made of the diameters of the main PA, the main PA to ascending aorta ratio, the proximal left and right PA diameters. The Investigators doing the measurements were blinded to the RHC data. Comparison was made between each of these measurements and the mean Pulmonary Artery Pressure (mPAP) measurement, as well as the PA systolic and the PA diastolic pressures.
RESULTS: There were 38 patients who qualified for the analysis. The mean time between CT scan and right heart catheterization was 3.24 months. Out of a total of 12 relationships evaluated, there was no significant correlation between any of the radiographic measurements and pressures. However, subgroup analysis of patients who had a CAT scan and RHC within one month (n=16, 42%) and female patients (n=8, 35%) showed linear correlations between Left PA diameter and mPAP (pearson r correlation coefficients of 0.60 and 0.88 respectively). Inter-observer concordance with measurements of the PA and segments was strong with a Cronbach's alpha >0.79 for all measures.
CONCLUSION: Although there was a linear correlation between LPA diameter and mPAP the correlation was not sufficiently robust to suffice as a screening tool for PH in patients with IPF.
CLINICAL IMPLICATIONS: CAT scans of the chest are useful for following the course of disease in patients with IPF, but other methods are required to assess for PH.
DISCLOSURE: Sean McKay, No Financial Disclosure Information; No Product/Research Disclosure Information