Right ventricle energy failure raises mortality risk in PH patients
RV failure may be important in predicting long-term outcomes: Researchers
About 1 in 4 people with pulmonary hypertension (PH) have right ventricle (RV) energy failure — when one of the heart’s lower chambers fails to provide enough energy to push blood to the lungs — a Turkish study found.
Researchers also observed that people with RV energy failure were more likely to die within five years than those without it, with a mortality risk about twofold on top of other factors already used to predict risk in this population.
“The presence of RV energy failure nearly doubles the mortality of PH even after correction for many established prognostic parameters,” the researchers wrote in “Right Ventricular Energy Failure Predicts Mortality in Patients With Pulmonary Hypertension,” which was published in The American Journal of Cardiology.
PH occurs when there’s high blood pressure in the pulmonary arteries, the vessels that supply the lungs. When this happens, the right side of the heart has to work harder to pump blood through them.
The right ventricle (the heart’s lower right chamber) generates potential energy as it contracts. Potential energy in the right ventricle is used in the passage of blood through the network of blood vessels in the lungs.
In healthy people, blood arriving to the left side of the heart — the one responsible for pumping blood out to the rest of the body’s tissues — has a higher pressure per volume than the blood in the RV at the beginning of the RV contraction. But in RV energy failure, blood arrives at the top left heart chamber with less pressure than the pressure during right ventricle filling.
RV energy failure and mortality risk
Researchers in Turkey wanted to know if RV energy failure could predict if people with PH are more likely to die over the long term, on top of the other factors that are already used to predict mortality.
They looked at data from 549 patients who’d had right heart catheterization between 2015 and 2022. Right heart catheterization is an invasive test that allows doctors to know how well a person’s heart is pumping. It’s used in the diagnosis of PH.
Their mean age was 56 and 343 (62.5%) were women. As for PH types, 147 (26.8%) were in group 1, 53 (9.7%) were in group 2, and six (1.1%) were in group 3. Almost two-thirds (62.5%) were in group 4. “As a tertiary center specialized on chronic thromboembolic PH, our PH cohort had a different distribution in terms of PH subgroups, which showed dominance of group IV patients,” the researchers said.
RV energy failure was present in 146 (26.6%). Over a five-year follow-up period, 77 (14%) patients died. When the researchers looked for differences in mortality, they found that those with RV energy failure were 4.25 times more likely to die within five years than those without it.
They also found that RV energy failure was a significant predictor of mortality when they looked at it in combination with other factors. The mortality risk was raised by 2.59 times on top of clinical parameters, and 2.05 times on top of hemodynamic (blood) parameters.
RV energy failure remained a significant predictor of mortality even after accounting for age, WHO classification group, distance walked on a six-minute walk test (a standard assessment of exercise capacity), and NT-proBNP level, an indicator of heart failure.
The presence of RV energy failure was significantly linked to worse survival, suggesting it may be an important factor to consider when predicting long-term outcomes with PH. The researchers said future trials should test whether the “addition of this hemodynamic parameter to the current risk scores would increase their predictive power.”