PH risk grows over time with COA, or narrowing of aorta: Study
Findings 'underscore' need for strategies to treat heart conditions tied to risk
People with coarctation of aorta, or COA — a condition marked by narrowing where the body’s largest blood vessel connects to the heart — are at high risk of developing pulmonary hypertension (PH), and this risk increases as time goes on, a study showed.
The data also showed that PH progression is associated with heightened mortality risk among people with COA, emphasizing a need for better treatment strategies in this patient population, according to the researchers.
“These findings underscore the clinical importance of [PH] in COA and [support] the need for new strategies for prevention and treatment of [heart conditions that increase PH risk],” the researchers wrote, noting that new therapies “should, in turn, slow the pace of [PH] progression in this [patient] population.”
The study, “Temporal changes in prevalence and severity of pulmonary hypertension, and relationship to outcomes in coarctation of aorta,” was published in the journal IJC Heart & Vasculature.
COA, marked by narrowing of aorta, already tied to higher PH risk
COA, a type of birth defect, occurs when the aorta — the large blood vessel that carries oxygen-rich blood from the heart out toward the rest of the body — is abnormally pinched or narrowed.
Previous studies have shown that people with COA are at increased risk of developing PH, which is marked by abnormally high pressure in pulmonary arteries, or the vessels that carry blood through the lungs. PH makes the heart’s right ventricle work harder to pump blood into the lungs.
However, whether PH risk in COA patients changes over time remained unclear.
To learn more, a team of researchers in the U.S. retrospectively analyzed data from 392 people with COA who were treated at Mayo Clinic from January 2003 to December 2017. Each of the patients underwent two or more echocardiograms — a technique used to image the heart and that can be used to assess PH — five or more years apart. The patients’ median age at the first echocardiogram was 35 years. Among them, 61% were men.
At the initial assessment, nearly 1 in 5 patients (19%) met criteria for PH, meaning they had right ventricular systolic pressure — known as RVSP, this measure estimates the pressure in pulmonary arteries — higher than 40 mmHg.
At the second assessment years later, more than 1 in 4 patients (27%) met PH criteria, implying that the risk of PH increases with time in COA patients.
RVSP values, which are commonly used as a proxy of PH severity, also increased significantly over time (by a mean of 5.6 mmHg), implying that PH may get more severe as time goes on in people with COA.
Statistical analyses showed that older age was significantly associated with an increased risk of PH in people with COA. Other heart conditions, such as atrial fibrillation, or an irregular heartbeat that begins in the heart’s upper chambers, as well as signs of left heart problems, also were significantly tied to a higher PH risk.
During a median follow-up of nearly 5.5 years, 50 patients (13%) died.
PH progression is clinically relevant because of its association with mortality in patients with COA.
Statistical analyses adjusted for potential influencing factors showed that for every 5 mmHg increase in RVSP between the first and second echocardiogram — reflecting increased pressure in pulmonary arteries — there was a 19% increase in the risk of death.
Also, a significantly lower proportion of patients experiencing greater PH progression, or highest RVSP increase, were estimated to be alive after 10 years relative to those with less PH progression, or lowest RVSP increase (82% vs. 95%).
These findings highlighted that “PH progression was associated with all-cause mortality, independent of [PH] severity at [first] echocardiogram,” the researchers wrote.
This “demonstrates that PH progression is clinically relevant because of its association with mortality in patients with COA,” and underscores the importance of strategies to prevent PH in people with COA, the team concluded.
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