PURPOSE: Chest computed tomography angiogram (CTA) is often performed as part of the diagnostic work-up for patients suspected of having pulmonary arterial hypertension (PAH). There is however conflicting data regarding its utility as a screening tool. The purpose of this study was to assess the predictive value of Pulmonary Artery Diameter (PAD), PAD/aorta diameter (AD) ratio and contrast medium reflux into the inferior vena cava (IVC) in diagnosing PAH (WHO group I).
METHODS: Patients referred for evaluation to our PAH center who received a chest CTA within 120 days of right heart catheterization (RHC) were retrospectively reviewed. CTA was independently reviewed by two physicians. PAD, AD and degree of contrast medium reflux into the IVC using a predetermined Likert scale (0-4) were measured. PAH was defined as mean pulmonary artery pressure (mPAP)>25mmHg and left ventricular end diastolic pressure (LVEDP) or pulmonary capillary wedge pressure (PCWP)< 15 mmHg by RHC. Data was analyzed using SAS(r) software.
RESULTS: Patients with PAH receiving a chest CTA within 120 days of RHC were considered for the study (n=49). The sensitivity and specificity of PAD>3.0 cm in predicting PAH was 81% and 67% respectively (OR:8.8, CI:1.4-56.4, p< 0.0225). The sensitivity and specificity of PAD/AD ratio>1 in predicting PAH was 74% and 67% respectively. The sensitivity and specificity of contrast medium reflux ≥3 was 44% and 50% respectively. Using a composite end point of PAD>3.0 cm, PAD/AD ratio>1 and contrast medium reflux ≥3 the sensitivity and specificity in predicting PAH was 33% and 83% respectively.
CONCLUSION: PAD>3 cm was associated with a greater likelihood of the presence of PAH. Additionally, predetermined composite endpoints based on CTA variables (PAD, PAD/AD ratio, contrast medium reflux into the IVC) may be used as a screening tool to predict the presence of PAH. Further studies are warranted to confirm our findings on a larger scale.
CLINICAL IMPLICATIONS: Chest CTA is an easily available non-invasive test which can be used as a valuable tool to predict PAH.
DISCLOSURE: Ali Sadoughi, No Financial Disclosure Information; No Product/Research Disclosure Information