Coronary artery stenosis may protect patients from the effects of pulmonary embolism

Acute pulmonary embolism (PE) is a life-threatening condition in which blood clots block vessels carrying deoxygenated blood from the heart to the lungs. This causes a sudden increase in blood pressure against the right ventricle (RV). As the heart struggles to pump blood past the clots, the strain can lead to RV failure and death. Acute PE also disrupts other cardiac and respiratory functions, which increases the risk of mortality.

Coronary artery disease (CAD) is a leading cause of cardiovascular death worldwide. The most common sign of CAD is the stiffening and narrowing of blood vessels that supply the heart, a condition called coronary artery stenosis (CAS). Studies have shown that patients with CAD are more likely to suffer from acute PE and have reduced life expectancy after PE is discovered. However, the effect of a “double hit” of CAS and PE on RV function has not been well studied

To understand possible associations between CAS, acute PE, and RV function, a team of Chinese researchers conducted a multicenter study of patients who were treated for acute PE. The team was led by Professor Zhi-Cheng Jing from Guangdong Provincial People's Hospital, and featured Dr. Yue-Jiao Ma and Ms. Jie-Ling Ma from Peking Union Medical College, Dr. Dan Lu from Peking University Aerospace Center Hospital, as well as other collaborators from Peking Union Medical College and Hebei Medical University. Their findings have been published in Volume 138, Issue 16 of the Chinese Medical Journal on August 20, 2025.

Describing the need for this research, Prof. Jing said, “The potential role of pre-existing CAS in acute PE remains poorly understood. Therefore, we conducted a case-control study to investigate the association between pre-existing CAS and RV dysfunction in patients with acute PE.”

The team looked through the records of patients who had been treated for acute PE between 2016 and 2020 across all participating centers. They identified 89 patients (cases) who had pre-existing CAS, and matched them by age and other characteristics to 176 patients without CAS (controls) at a 1:2 ratio. They then compared cardiac dysfunction markers, PE severity metrics, and prevalence of co-morbidities in case and control patients.

To their surprise, the team found that patients with CAS had fewer signs of RV strain than those without. On average, case patients had lower heart rates, lower NT-proBNP levels (a biomarker of cardiac strain), and a lower prevalence of elevated systolic pulmonary artery pressure (≥40 mmHg). What made this result surprising is that case patients also had a much higher prevalence rate of co-morbidities linked to PE, such as diabetes, hypertension, hyperlipidemia, and atherosclerosis.

“CAS was independently and negatively associated with RV dysfunction,” said Prof. Jing when discussing the findings. He added, “There was a stronger negative association between stenosis of the left anterior descending artery and RV dysfunction,” to point out that some coronary arteries had a greater effect than others. In their analysis, the team found that CAS was an independent protective factor, reducing the risk of RV dysfunction among case patients by nearly threefold.

Moreover, case patients with narrowing in two or more coronary arteries had even lower rates of RV dysfunction and other markers of cardiac stress than those with stenosis in only one artery. While the mechanisms remain uncertain, the researchers suggest that compensatory changes to the heart, such as collateral vessel growth and myocardial adaptation, or medication use (e.g. statins) could contribute to these paradoxical findings.

These findings hold crucial implications for the diagnosis and treatment of acute PE, especially concerning accurately identifying patients at risk of RV dysfunction. “This study alerts physicians to pay closer attention to changes in RV function in patients with pre-existing CAS during the long-term management of acute PE,” concludes Prof. Jing

One hopes that future research will help all patients with acute pulmonary embolism receive timely care appropriate to their risk status.