Widespread coronary inflammation in unstable angina

Area of Science:

• Cardiology
• Immunology
• Vascular Biology

Background:

• Inflammation in coronary plaques can lead to unstable angina through rupture or erosion.
• Leukocyte activation is observed in unstable angina, but selective activation within the culprit stenosis vascular bed remains unclear.

Purpose of the Study:

• To investigate whether neutrophils are selectively activated in the coronary vascular bed of patients with unstable angina.
• To measure neutrophil myeloperoxidase (MPO) content in cardiac and femoral circulations across different patient groups.

Main Methods:

• Neutrophil myeloperoxidase (MPO) content was measured in aortic, femoral vein, and great cardiac vein blood samples.
• Five groups were studied: unstable angina (left or right coronary artery stenosis), chronic stable angina, variant angina, and controls.
• The great cardiac vein selectively drains blood from the left coronary artery.

Main Results:

• Neutrophil MPO content was significantly lower in the aortic blood of unstable angina patients compared to other groups.
• A significant transcoronary reduction in MPO content was observed in unstable angina patients, irrespective of stenosis location.
• No significant MPO reduction was found in stable angina, variant angina, or control groups.

Conclusions:

• Neutrophil activation is widespread throughout the coronary vascular bed in unstable angina.
• Findings challenge the traditional concept of a single vulnerable plaque as the sole driver of unstable coronary syndromes.