Comparison of diagnostic tests used in the evaluation for CTEPH
| Diagnostic test . | Findings in CTEPH . | Advantages . | Disadvantages/limitations . |
|---|---|---|---|
| Imaging | |||
| Echocardiogram | • Evidence of PH or RH strain: RV dilation, RV systolic dysfunction, RA dilation, PASP elevation, flattening of interventricular septum | • Non-invasive • No exposure to radiation or contrast dye | • Not specific or sensitive to CTEPH • Misses CTED |
| VQ | • Mismatched defects in perfusion and ventilation defects • Heterogeneity of perfusion | • Highest sensitivity to rule out CTEPH • Less radiation exposure • No contrast dye exposure | • Limited access as performed in nuclear medicine • Unable to provide alternative diagnosis • Sensitive but not specific for CTEPH |
| CT PA | • Pulmonary arteries: PA dilation, webs/bands, eccentric filling defects, mural thrombi, luminal narrowing with poststenotic dilation, complete occlusion, pouch defects • Heart: RV dilation, septal flattening • Lungs: mosaic attenuation, large bronchial artery collaterals | • Defining vascular anatomy can aid in surgical assessment • Provides data on screening for concomitant lung disease/alternate diagnosis that can aid in surgical risk assessment | • CTEPH findings can sometimes be subtle and require expertise and attention to diagnose • Exposure to IV contrast • Exposure to radiation • Less sensitive than VQ (neg CT does not exclude CTEPH) |
| Invasive testing | |||
| Pulmonary angiogram | • Ring lesions/ring-like stenosis • Poststenotic dilation • Total occlusion • Vascular webs | • Provides complete hemodynamic assessment and aids in surgical planning | • Invasive |
| RH catheterization | • mPAP ≥25 mm Hg • Wedge ≤15 mm Hg | • Provides complete hemodynamic assessment and aids in surgical planning | • Invasive |
| Functional testing | |||
| Cardiopulmonary exercise testing | • Increased dead space ventilation with widening A-a gradient, flattened stroke volume in response to exercise | • Can detect limitations in function and cardiopulmonary response to exercise | • Requires specialized testing unit • Requires arterial blood gas measurement |
| 6-minute walk test | • Functional limitations and decreased oxygen saturation with exercise | • Simple to perform, low cost, minimal risk | • Not specific to CTEPH |
| Diagnostic test . | Findings in CTEPH . | Advantages . | Disadvantages/limitations . |
|---|---|---|---|
| Imaging | |||
| Echocardiogram | • Evidence of PH or RH strain: RV dilation, RV systolic dysfunction, RA dilation, PASP elevation, flattening of interventricular septum | • Non-invasive • No exposure to radiation or contrast dye | • Not specific or sensitive to CTEPH • Misses CTED |
| VQ | • Mismatched defects in perfusion and ventilation defects • Heterogeneity of perfusion | • Highest sensitivity to rule out CTEPH • Less radiation exposure • No contrast dye exposure | • Limited access as performed in nuclear medicine • Unable to provide alternative diagnosis • Sensitive but not specific for CTEPH |
| CT PA | • Pulmonary arteries: PA dilation, webs/bands, eccentric filling defects, mural thrombi, luminal narrowing with poststenotic dilation, complete occlusion, pouch defects • Heart: RV dilation, septal flattening • Lungs: mosaic attenuation, large bronchial artery collaterals | • Defining vascular anatomy can aid in surgical assessment • Provides data on screening for concomitant lung disease/alternate diagnosis that can aid in surgical risk assessment | • CTEPH findings can sometimes be subtle and require expertise and attention to diagnose • Exposure to IV contrast • Exposure to radiation • Less sensitive than VQ (neg CT does not exclude CTEPH) |
| Invasive testing | |||
| Pulmonary angiogram | • Ring lesions/ring-like stenosis • Poststenotic dilation • Total occlusion • Vascular webs | • Provides complete hemodynamic assessment and aids in surgical planning | • Invasive |
| RH catheterization | • mPAP ≥25 mm Hg • Wedge ≤15 mm Hg | • Provides complete hemodynamic assessment and aids in surgical planning | • Invasive |
| Functional testing | |||
| Cardiopulmonary exercise testing | • Increased dead space ventilation with widening A-a gradient, flattened stroke volume in response to exercise | • Can detect limitations in function and cardiopulmonary response to exercise | • Requires specialized testing unit • Requires arterial blood gas measurement |
| 6-minute walk test | • Functional limitations and decreased oxygen saturation with exercise | • Simple to perform, low cost, minimal risk | • Not specific to CTEPH |
IV, intravenous; PASP, pulmonary artery systolic pressure; RA, right atrium.