Radiologic signs may aid early chronic thromboembolic pulmonary hypertension detection

Key takeaways:

• CT pulmonary angiography is an important tool for finding signs of chronic thromboembolic pulmonary hypertension.
• This disease cannot be predicted by one specific finding on a CT scan.

Early detection of chronic thromboembolic pulmonary hypertension may be achieved with use of predefined signs on a CT scan following acute pulmonary embolism diagnosis, according to results published in CHEST.

“Although no single radiologic finding indicating chronicity seems to be robust and reproducible enough to predict chronic thromboembolic pulmonary hypertension (CTEPH) diagnosis, fulfilment of an increasing number of criteria from a list of predefined radiologic parameters increases the level of agreement between radiologists and the specificity of predictive models,” Stefano Barco, MD, PhD, research group leader at the Center for Thrombosis and Hemostasis at the University Medical Center Mainz, Germany, and staff physician in the Clinic of Angiology at the University Hospital Zurich, and colleagues wrote.

In a large prospective multicenter cohort study, Barco and colleagues evaluated 303 patients (median age, 63 years; 44.6% female) with acute PE and at least 2 years of follow-up data to see if CT pulmonary angiography findings could signal whether a patient has CTEPH.

Using baseline CT pulmonary angiograms, two radiologists determined whether a patient had preexisting CTEPH, with a third radiologist utilized in the case of disagreement, and they assessed for chronic PE and pulmonary hypertension, according to researchers.

Of the total cohort, 46 patients (15.2%; median age, 64 years; 45.7% female) presented with indicators for chronic PE or CTEPH on their CT pulmonary angiograms. Researchers noted four main radiographic findings in these patients: intravascular webs, arterial narrowing/retraction, dilated bronchial arteries and right ventricular hypertrophy.

When assessing 2-year outcomes based on the presence of signs for chronic PE or CTEPH, those with indicators for these diagnoses vs. those without indicators demonstrated poorer European Quality of Life index scores (0.84 vs. 0.94), poorer PE quality-of-life global scores (20 vs. 10) and more post-PE impairment (24.2% vs. 13.9%).

In the follow-up assessment of the entire study population, clinicians diagnosed CTEPH in five patients (1.7%), four of whom were categorized at baseline in the group with chronic PE or CTEPH by the radiologists. Based on this finding, the probability for receiving a CTEPH diagnosis in a follow-up evaluation was 8.7%.

Further, the four patients outlined above also received their diagnosis of CTEPH within 83 to 108 days after their diagnosis of acute PE, whereas the fifth patient was diagnosed 485 days after follow-up.

“This observation supports the notion that this particular patient was the only one who developed CTEPH de novo, following the index acute PE event,” Barco and colleagues wrote.

When assessing if radiologic factors observed on CT were related to the outcome of CTEPH, researchers found the two radiologist’s judgments differed; however, the four patients still fit into enriched subgroups that met a minimum number of radiologic signs.

According to researchers, when more required criteria were given in the evaluation of patients’ CT pulmonary angiograms, agreement increased among the radiologists and the specificity of preexisting CTEPH diagnosis improved.

“These findings will help to optimize algorithms for post-PE patient care,” Barco and colleagues wrote. “In particular, they may contribute to identifying, in the acute phase and prior to discharge from the hospital, a group of patients in whom intensified follow-up and, possibly, early CTEPH screening may be indicated.”