Circulating Ectonucleotidases Signal Impaired Myocardial Perfusion at Rest and Stress

Area of Science:

• Cardiovascular Biology
• Biomarker Discovery
• Enzymology

Background:

• Ectonucleotidases (CD39, CD73) are crucial for vascular homeostasis, regulating inflammation and thrombosis.
• Their dysfunction is linked to human diseases, but plasma levels as biomarkers for coronary artery dysfunction are unstudied.

Purpose of the Study:

• To investigate the utility of plasma ectonucleotidase (CD39, CD73) levels as biomarkers for coronary artery dysfunction.
• To determine the association between circulating ectonucleotidase levels and myocardial blood flow or reserve.

Main Methods:

• Retrospective analysis of 529 individuals undergoing positron emission tomography stress testing.
• Assessed plasma CD39 and CD73 levels using ELISAs.
• Correlated enzyme levels with clinical data, stress test results, and coronary artery calcium scores.

Main Results:

• Plasma CD39 levels differed significantly between White and Black participants.
• Ectonucleotidase levels were associated with liver disease but not traditional coronary artery disease risk factors.
• Detectable CD39 levels inversely correlated with stress myocardial blood flow; CD73 inversely correlated with global myocardial flow reserve, independent of liver disease.

Conclusions:

• Plasma ectonucleotidase levels show an inverse relationship with stress myocardial blood flow (CD39) and myocardial flow reserve (CD73).
• Shed ectonucleotidases may contribute to reduced myocardial blood flow and reserve, suggesting potential as novel biomarkers.