Chest computed tomography (CT) imaging is often performed in evaluation of patients with pulmonary hypertension (PH). An enlarged pulmonary artery on CT has been considered suggestive of PH however this association has never been quantified. The purpose of this study was to compare three different decision rules which could be used in screening for PH.
Patients referred for evaluation to our PH center who received a chest CT within 120 days of right heart catheterization (RHC) were retrospectively reviewed. Pulmonary artery diameter (PAD) and PAD/aorta diameter (AD) ratio were measured from a single defined CT section. Sensitivity and specificity were calculated for PAD > 3cm, PAD/AD ratio > 1, and combined PAD > 3cm and PAD/AD ratio > 1. Logistic regression was used to examine the relationship between each decision rule and PH (mean pulmonary artery pressure (MPAP) > 25mmHg). The study evaluated all patients referred for suspected PH regardless of etiology as this radiological screening test should not be affected by etiology of PH.
90 patients had a chest CT within 120days of RHC. 73 patients had PH (MPAP > 25mmHg). Sensitivity and specificity of PAD > 3cm for predicting PH, was 86.3% and 82.4% respectively. The odds ratio of predicting PH was 29.4 (95% CI: 7.1 –120.9).Sensitivity and specificity of PAD/AD ratio > 1 for predicting PH, was 75.3% and 76.5% respectively. The odds ratio of predicting PH was 9.9 (95% CI: 2.9 –34.3). Sensitivity and specificity of PAD > 3cm and PAD/AD ratio > 1 for predicting PH was 72.6% and 88.2% respectively. The odds ratio of predicting PH was 19.9 (95% CI: 4.2 –94.8).
This study demonstrates that parameters from chest CT may have use in the screening of PH. PAD > 3cm had the highest sensitivity and odds ratio. Combining PAD > 3cm and PAD/AD ratio > 1 increased the specificity but decreased the sensitivity.
Clinicians should consider main PA diameter in conjunction with PAD/AD ratio to help predict PH while reviewing CT angiograms.Physicians should be aware of the utility of combined data on chest CT in the screening of patients for PH.
Pralay Sarkar, No Financial Disclosure Information; No Product/Research Disclosure Information