Acute pulmonary embolism (PE) occurs when blood clots block vessels carrying deoxygenated blood from the heart to the lungs, triggering a sudden rise in pressure against the right ventricle and risking rapid heart failure. Coronary artery stenosis (CAS), meanwhile, is a hallmark of coronary artery disease and is typically associated with worse cardiovascular outcomes. Although patients with CAS are known to have poorer long-term survival after PE, the combined impact of CAS and acute PE on right-ventricular (RV) function has remained unclear. Now, a new study has provided an unexpected finding that pre-existing vessel narrowing may actually reduce RV strain.

The study, led by Guangdong Provincial People's Hospital (Guangzhou, China), involved a case-control analysis of 89 patients with CAS and 176 matched controls treated for acute PE between 2016 and 2020 across participating centers. Clinical markers of cardiac strain, PE severity, and co-morbidities were compared to determine whether CAS influenced RV dysfunction risk.

Despite having higher rates of diabetes, hypertension, hyperlipidemia, and atherosclerosis, patients with CAS showed fewer signs of RV strain. They had lower heart rates, lower NT-proBNP levels, and a reduced prevalence of elevated systolic pulmonary artery pressure (≥40 mmHg) compared with controls. CAS emerged as an independent protective factor, decreasing the likelihood of RV dysfunction nearly threefold.

Narrowing of the left anterior descending artery showed the strongest negative association with RV impairment, and patients with multivessel stenosis demonstrated even fewer markers of cardiac stress. Possible explanations include collateral vessel formation, myocardial adaptation, or medication effects such as statin therapy.

These findings, published in Chinese Medical Journal, could refine risk assessment in acute PE by highlighting how pre-existing coronary disease may alter RV response to clot burden. As researchers note, careful attention to RV function remains essential in patients with concurrent CAS, particularly during long-term management.

“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,” said Professor Zhi-Cheng Jing, who led the research team.

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