PURPOSE: Right-heart catheterization is currently the gold standard used to detect pulmonary hypertension (PH) and to grade its severity. However, cardiac catheterization, like any invasive procedure, is associated with important risks and complications. CT scanning of the chest is a non-invasive investigative modality commonly used in the diagnosis and management of patients with pulmonary pathology. The purpose of our study is to determine the utility of CT scans for detecting PH in patients, thereby avoiding the use of invasive right-heart catheterization.
METHODS: A retrospective review was conducted on 40 patients with left-sided cardiac pathology who had undergone both right-heart catheterization and CT scanning of the chest. Patients with catheterized-measured pulmonary artery pressures (PAP) between 25-40mmHg and >40mmHg were identified as having mild-moderate and severe pulmonary hypertension respectively. Mean pulmonary artery diameters (MPAD) were then measured on CT scans at the widest portion of the main pulmonary artery within 3mm of the bifurcation. Values are presented as means± 1S.E.M.
RESULTS: Statistical analysis using one-way ANOVA followed by Tukey’s test for multiple comparisons showed that patients with mild-moderate PH have significantly greater CT-measured MPAD (34.89± 1.01) than controls (27.36± 0.83, p< 0.001). Furthermore, patients with severe PH were found to have significantly greater MPAD (38.31± 0.88) than both mild-moderate PH patients (p< 0.01) and controls (p< 0.001). Receiver-operating characteristic (ROC) curve analysis showed that CT scanning was able to predict PH with an area under the curve of 0.95(p< 0.0001). Fisher’s exact testing reveals a cut-off MPAD measurement of >34mm has a specificity of 100% and a positive predictive value of 100% (N=40, p< 0.0001) and a cut-off MPAD measurement of < 27mm has a sensitivity of 100% with a negative predictive value of 100% (N=40, p< 0.001).
CONCLUSION: Our analysis reveals that CT scanning is able to correctly identify all patients with PH when using a cut-off MPAD measurement of >34mm as well as correctly rule out PH in patients with MPADs < 27mm.
CLINICAL IMPLICATIONS: Our study demonstrates that CT scanning may provide clinicians with an excellent diagnostic tool for detecting PH.
DISCLOSURE: Jennifer Kam, No Financial Disclosure Information; No Product/Research Disclosure Information