[Sportschosun Reporter Jang Jong-ho] A research team led by Hwang In-chang and Jiesuck Park, professors of cardiology at Seoul National University Bundang Hospital, and co-corresponding author Kim Hyung-kwan, a professor of cardiology at Seoul National University Hospital, has found that the risk of death is 3.5 times higher when left atrial function fails to recover even after left ventricular function improves with heart failure treatment.
Heart failure is a condition in which damaged heart muscle cannot pump enough blood to meet the body's needs. When the heart's pumping function gradually declines due to conditions such as myocardial infarction or high blood pressure, patients may become short of breath and tire easily even with minimal activity. Blood that cannot be pumped out properly can also become congested, causing fluid to build up in the lungs or swelling in the legs.
A type of heart failure in which the heart's ability to eject blood is weakened is called heart failure with reduced ejection fraction. As angiotensin receptor-neprilysin inhibitor (ARNI) therapy, which suppresses hormones that place strain on the heart, has become a standard treatment, the goal has expanded beyond relieving symptoms to restoring the weakened heart as close as possible to its original condition.
Until now, treatment response has been assessed mainly by focusing on the left ventricle. Because the left ventricle is the heart's main pump for sending blood throughout the body, clinicians have evaluated treatment response by measuring how much the ejection fraction—the proportion of blood pumped out with each contraction—has increased. For the left atrium, assessment has generally been limited to checking how much its size has changed.
The left atrium receives blood returning from the lungs and passes it to the left ventricle. If the weakened left ventricle cannot pump out enough blood, pressure inside it rises. That burden is then transmitted to the left atrium, which passes blood into the ventricle, and its function gradually declines over time. It had remained unclear whether a damaged left atrium also recovers during treatment and, if it does not, what impact this has on patients.
The research team therefore used strain echocardiography, which precisely measures the movement and deformation of heart muscle, to examine functional recovery in the left ventricle and left atrium. The researchers analyzed 1,182 heart failure patients who began ARNI treatment at Seoul National University Bundang Hospital or Seoul National University Hospital between 2017 and 2022 and had test results available both before treatment and one year later.
Based on changes over the first year, the patients were divided into four groups: recovery of both the left ventricle and left atrium; recovery of the left ventricle only; recovery of the left atrium only; and recovery of neither. Long-term outcomes were then tracked for approximately 26 months.
The results showed that even when left ventricular function recovered, the risk of death remained high if left atrial function did not recover as well. Patients whose left ventricular function alone recovered accounted for 11.2% of the total. Compared with patients whose two functions both recovered, they had a 3.53-fold higher risk of death from any cause and a 5.68-fold higher risk of cardiovascular death. These figures were similar to the risks among patients whose left ventricular and left atrial functions both failed to recover—3.35-fold and 6.00-fold, respectively.
In patients whose left ventricular function alone recovered, the left atrium remained enlarged and pressure inside the heart did not fall sufficiently, indicating that strain persisted. The research team explained that the left atrium may have already sustained damage that was difficult to reverse, preventing it from recovering along with the left ventricle.
The team then conducted an additional analysis to determine whether these patients could be identified using the conventional measures of left ventricular ejection fraction and left atrial size. Although this approach detected the risk among patients whose two functions failed to recover, it did not clearly reveal the mortality risk among those whose left ventricular function alone recovered. This suggests that conventional tests alone may make it difficult to identify this high-risk group.
The study is significant because it provides evidence that both the left ventricle and left atrium should be assessed when evaluating the success of heart failure treatment. It also demonstrated the clinical value of strain echocardiography for detecting these changes. The technique is expected to enable more precise identification of high-risk patients who may not be detected through conventional testing.
Co-corresponding author Hwang In-chang said, "The left atrium is where the burden the heart has endured over time accumulates, so its recovery should be monitored as well." He added, "For patients whose left atrial function fails to keep pace, more proactive management could be considered, such as adjusting medication or taking a closer look at whether fluid is accumulating in the body."
First author Jiesuck Park said, "Our next task is to determine why left atrial function fails to recover and which patients show this pattern." He added, "We will investigate the actual changes occurring in the left atrium through cardiac MRI and other methods and pursue research aimed at identifying the possibility of recovery."
The findings were published in the European Journal of Heart Failure (EJHF), a leading international journal in the field of heart failure, which has an impact factor of 10.3.
Jang Jong-ho, bellho@sportschosun.com
This article has been translated by GripLabs Mingo AI.
