New Virtual Tool May Allow Fast, Accurate PH Diagnosis During COVID-19, Study Says
A new virtual tool, called VEST, is aiding clinicians in remotely diagnosing people with Group 1 pulmonary hypertension (PH) per the World Health Organization (WHO) classification, a new study reports.
VEST, short for virtual echocardiography screening tool, uses images from routine echocardiography exams of a person’s heart to diagnose PH. Researchers say this represents an advance for virtual care during the current COVID-19 pandemic, since clinical resources may be more limited and PH patients are considered a high-risk group.
The study, “Virtual echocardiography screening tool to differentiate hemodynamic profiles in pulmonary hypertension,” was published in the journal Pulmonary Circulation.
Since the COVID-19 pandemic started, it became evident that people with PH are among those at risk for worse outcomes, if infected. Changes in clinical practice have been implemented to minimize patients’ exposure, with only urgent cases of hospitalization or clinical assessment being evaluated in person.
Right heart catheterization (RHC), which measures blood properties on the heart’s right chamber, is the gold standard method to diagnose people with different subtypes of PH. But it is an invasive exam that must be done in a medical center.
With PH patients being managed virtually and remotely during the pandemic, evaluations by RHC have been greatly reduced. However, this could have serious implications for those with PH, “where delays in accurate diagnosis and subsequent initiation of PH-specific therapies pose a significant risk on morbidity and mortality,” the investigators wrote.
Thus, a team led by researchers at the Lewis Katz School of Medicine at Temple University (LKSOM) developed a new tool that allows the remote diagnosis of different subtypes of PH.
The tool, called VEST, is based on echocardiography, a traditional and routine exam that captures images and important parameters — including the size and shape of the heart chambers — of blood circulation in the heart.
“VEST enables physicians to quickly evaluate patients for pulmonary hypertension by simply searching for routine key measures indicated in echocardiogram reports,” Anjali Vaidya, MD, the study’s lead author, said in a press release.
Vaidya is the co-director of the Pulmonary Hypertension, Right Heart Failure & CTEPH Program at Temple University Hospital, in Philadelphia, and an associate professor of Medicine at LKSOM.
VEST uses data from several parameters measured in echocardiograms to predict blood flow in PH and diagnose PH due to pulmonary vascular disease. The diagnostic tool gives a score ranging from -3 to +3, in which higher scores indicate a higher probability of PH due to pulmonary vascular disease.
First, the researchers tested VEST in a group of 96 patients (mean age 62.4 years, 68.7% women) diagnosed with PH with available echocardiography and RHC data. The median period between RHC and echocardiographic assessment was 27.5 days.
In total, 42 patients (43.8%) were diagnosed with WHO Group 1 pulmonary hypertension and 32 (33.3%) with WHO Group 2. An additional 12 patients (12.5%) were evaluated as belonging to WHO Group 3, while six (6.3%) were identified as WHO Group 4 and four (4.2%) as WHO Group 5.
Researchers found that a VEST score above zero had an 80.0% sensitivity and a 75.6% specificity for diagnosing PH due to pulmonary vascular disease (WHO Group 1). Of note, a test’s sensitivity is its ability to correctly identify those with a given disease, while specificity refers to correctly identifying those without it.
Meanwhile, a VEST score of +3 was 92.7% specific, with a predictive value of 88.0%. Negative vest scores were predictive of WHO Group 2 PH.
Overall, a positive VEST score was 83.7% sensitive and 66.0% specific for the diagnosis of WHO Group 1 PH.
“We demonstrated that this novel VEST using three routine parameters that can be easily extracted from standard echocardiographic reports can successfully capture PH patients with a high likelihood of PHPVD [PH due to pulmonary vascular disease],” the researchers wrote.
Then, the team tested a simpler echocardiography parameter, known as e-velocity, in replacement for one of the three initial parameters that was harder to assess. Results showed that this simplified VEST score had similar outcomes to the original VEST, with a 81.4% sensitivity and a 69.4% specificity.
Moreover, it also allowed the team to discriminate PH due to pulmonary vascular disease (WHO Group 1) from other WHO PH groups.
Next, the results were validated in a second group of 30 patients, including 10 with PH due to pulmonary vascular disease and 20 with PH not linked with vascular disease.
In this second group, a positive VEST score (greater than zero) was 100.0% sensitive and 75.0% specific for a diagnosis of PH due to pulmonary vascular disease. A VEST score of +3 was 90.0% specific for the same diagnosis.
“This is the first time that routine interpretation of echocardiogram reports, without direct advanced review of imaging, has proven to be effective,” Vaidya said. “By using parameters routinely reported in echocardiograms to assess hemodynamic profiles, VEST truly facilitates the diagnosis of pulmonary hypertension.”
Vaidya said this will be useful during the continuing pandemic as clinicians try to diagnose PH.
“VEST makes early recognition of the condition possible, allowing patients to receive more timely referral for appropriate evaluation. The fact that this can be done remotely during virtual telemedicine visits is especially relevant in the COVID-19 era,” Vaidya added.
In the future, the researchers aim to assess VEST’s long-term impact on PH patient outcomes.
“Now that we have a tool for assisting virtual diagnosis of pulmonary hypertension that any physician could use, we have a real opportunity to examine long-term outcomes in patients referred for treatment based on VEST findings,” Vaidya concluded.