Measuring blood vessel function in arm may help predict PH: Study
Noninvasive flow-mediated dilation test 'useful tool' to screen for suspected PH
![Blood cells are shown flowing through a blood vessel.](https://pulmonaryhypertensionnews.com/wp-content/uploads/2024/03/blood-vessel.png)
Measuring blood vessel function in the arm in a noninvasive way can help predict pulmonary hypertension (PH) when combined with certain heart measurements, a study has found.
The study, “Endothelial Function Correlates With Pulmonary Pressures in Subjects With Clinically Suspected Pulmonary Hypertension,” was published in The American Journal of Cardiology.
PH occurs when blood pressure in the pulmonary arteries that carry blood from the heart to the lungs is too high. This increased pressure can lead to serious problems, such as heart failure. To understand PH better, it’s important to study how blood flows through these arteries.
In PH, blood flow is impaired, which means higher pressure in the pulmonary arteries (PAP) and increased pulmonary vascular resistance (PVR). Researchers in Italy wanted to see if there was a link between the health of the endothelial cells that make up the blood vessel linings and these measurements.
To test this, they used a test called flow-mediated dilation (FMD), which checks how well the artery in the arm expands when blood flow increases.
The study included 95 patients suspected of having PH, who were a mean age of 63 years and 58% of them were male. Each patient underwent FMD and right-sided heart catheterization to measure blood pressure in the heart and lungs, including PAP and PVR. The catheterization is an invasive procedure that provides precise measurements.
As blood vessel health worsens, pressure in pulmonary arteries increases
Results showed that lower FMD values, indicating poorer blood vessel health, were linked to higher systolic PAP. This means that as blood vessel health worsens, the pressure in the pulmonary arteries increases. The link with PVR was less clear.
Further analysis, taking into account factors such as age, sex, and other heart function measurements, confirmed that FMD is a significant predictor of systolic PAP. This means that even when considering these other factors, FMD remains an important indicator.
The study also grouped patients based on their FMD and another measurement called peak tricuspid regurgitation velocity (TRV). Patients with both impaired FMD and peak TRV had the highest systolic PAP, mean PAP, and PVR levels. This trend suggests that combining these two measurements can better predict PH.
The study found poorer blood vessel health, as measured by FMD, is linked to higher pulmonary artery pressure in patients with suspected PH. Combining FMD with peak TRV provides a useful, noninvasive way to predict the severity of PH, which can help in its diagnosis and treatment.
“The assessment of endothelial function by FMD is relatively simple, feasible, cheap, and noninvasive, thus possibly representing an innovative tool for the clinical screening of patients with suspected PH,” the scientists wrote.
“Future studies are needed to ascertain whether FMD may represent a possible useful tool for risk stratification, treatment, and outcome modification in [pulmonary arterial hypertension],” they added.