Heart valve abnormality may signal risk in low-risk PAH patients
Tricuspid regurgitation, or TR, can be detected in echocardiography
The degree of tricuspid regurgitation (TR), a cardiac abnormality detected in a heart ultrasound, may help predict the outcomes in people with pulmonary arterial hypertension (PAH), a study suggests.
Those with more advanced TR were at a higher risk of death. This relationship was seen specifically in the subgroup who would’ve been considered low risk based on other measures.
“The present data may pave the way for future studies testing the added value of TR in prognostic tools,” the researchers wrote. The study, “Clinical and prognostic role of tricuspid regurgitation in incident patients with pulmonary arterial hypertension,” was published in ERJ Open Research.
In PAH, it’s harder for the heart to pump blood due to elevated pressure in the pulmonary arteries that carry blood through the lungs. This can lead eventually to right-sided heart failure.
Echocardiography, or a heart ultrasound, is a noninvasive imaging test that visualizes the heart’s structure and function. It’s often used to diagnose and monitor PAH, and to predict a person’s prognosis. A TR can be measured with an echocardiogram and has been linked to poor survival in PAH. In it, the valve that controls blood flow between the heart’s two right chambers doesn’t close properly, letting some blood flow backward during a heartbeat. This means the heart has to work harder to pump enough blood to the lungs.
Measuring TR, predicting prognosis
Here, scientists retrospectively reviewed echocardiography data in 147 newly diagnosed adults with PAH who were seen at their clinic in London between 2011 and 2021 to learn more about the utility of TR measurements for predicting prognosis in PAH. Those with at least moderate TR showed indicators of worse right-sided heart function than those with mild TR or who were without TR.
Specifically, these adults had a lower tricuspid annular plane systolic excursion (TAPSE), an indicator of how well the heart’s right ventricle is working. They also had a decreased TAPSE to systolic pulmonary artery pressure (sPAP) ratio, which indicates the right side of the heart isn’t coping well with elevated pressure in the lungs. Reduced TAPSE and TAPSE/sPAP are established prognostic markers in PAH, and are associated with worse outcomes.
Those with at least moderate TR also had higher pressure in the right side of the heart, as assessed with a right heart catheterization, along with increased pulmonary vascular resistance, a measure of how hard the right side of the heart has to work to pump blood to the lungs.
In exercise testing, people with more severe TR took up less oxygen during aerobic exercise than those with less severe TR.
Over a median follow-up of 38.8 months, or just over three years, 46 people died. Having moderate or worse TR was the only echocardiographic measure associated with worse survival in statistical analyses, after adjusting for age and sex.
When categorizing people based on whether they had a reduced or preserved TAPSE, TR was only a prognostic factor in people with a normal TAPSE value. Likewise, when categorizing people as low, intermediate, or high risk in terms of the TAPSE/sPAP ratio, it was only a prognostic factor in low-risk individuals.
“This is a relevant message for clinicians because a normal TAPSE/sPAP is per se considered, in the latest … guidelines, an indicator of low risk, which may not be true for all patients,” wrote the researchers, who said some people considered low risk by TAPSE or TAPSE/sPAP may actually be at a more intermediate risk of disease progression if they have a greater degree of TR. They called the presence of TR of moderate degree or more “the most important echocardiographic indicator of poor prognosis in treatment-naive PAH patients.”
Still, exploring this relationship further and establishing TR as a prognostic marker for clinical use requires more research, they said.
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