Intraplaque hemorrhage in cardiac allograft vasculopathy

Area of Science:

• Cardiovascular Pathology
• Transplant Medicine
• Atherosclerosis Research

Background:

• Plaque vulnerability in native coronary atherosclerosis is influenced by hemorrhage, inflammation, and microvessel density.
• Cardiac allograft vasculopathy (CAV) is a significant concern in heart transplant recipients.
• Understanding CAV plaque characteristics is crucial for managing transplant outcomes.

Purpose of the Study:

• To investigate the presence and significance of intraplaque hemorrhage (IPH) in CAV lesions.
• To examine the relationship between IPH, inflammation, and microvessel density in CAV.
• To compare IPH prevalence in CAV versus native coronary artery disease.

Main Methods:

• Analysis of 70 coronary plaques from 12 heart transplant recipients who died from CAV.
• Semi-quantitative assessment of intralesional inflammation, microvessels, and IPH.
• Comparison of CAV plaques with native coronary artery disease (ATS) plaques from the same patients.

Main Results:

• IPH was found in 60% of CAV lesions versus 22.9% of native ATS plaques.
• A strong association was observed between fibrocellular lesions and IPH in CAV (p = 0.0142).
• Microvessels were detected in 74.3% of CAV lesions, with endothelial damage signs in 69.2%.
• IPH was strongly associated with microvessels (p < 0.0001) and inflammation (present in 88.6% of CAV lesions).
• CAV lesions with IPH often contained both fresh and old hemorrhage (57.1%).

Conclusions:

• IPH is a significant feature of CAV, frequently associated with microvessel damage and inflammation.
• The presence of fresh and old hemorrhage suggests ongoing plaque remodeling and progression in CAV.
• IPH contributes to the vulnerability of cardiac allografts, impacting long-term transplant survival.