[Chronic cardiac rejection. 20 anatomico-clinical cases]

Area of Science:

• Cardiology
• Transplantation Immunology
• Pathology

Background:

• Chronic cardiac rejection is a major long-term complication following heart transplantation.
• Accelerated coronary artery disease (cardiac allograft vasculopathy) significantly impacts graft survival and patient outcomes.
• Understanding the anatomical and pathological features of this condition is crucial for diagnosis and management.

Purpose of the Study:

• To investigate the detailed anatomical and histopathological features of coronary lesions in chronic cardiac rejection.
• To correlate these findings with coronary angiographic appearances.
• To explore potential aetiopathological factors contributing to accelerated coronary disease post-transplant.

Main Methods:

• Anatomico-clinical study of 20 consecutive cases of chronic cardiac rejection after heart transplantation.
• Detailed histopathological analysis of coronary lesions, including epicardial and intramyocardial branches.
• Correlation of pathological findings with coronary angiographic images.

Main Results:

• Observed diffuse, circumferential atherosclerotic alterations with less individualized plaques than typical atherosclerosis.
• Frequent and multifocal thrombosis occurred in 50% of cases, leading to massive or disseminated myocardial ischemia.
• Painless ischemic cardiomyopathy due to denervation resulted in cardiac failure, necessitating retransplantation or leading to autopsy.
• Coronary angiography tended to underestimate the severity of coronary damage.

Conclusions:

• Chronic cardiac rejection manifests as a unique, diffuse coronary vasculopathy with frequent thrombosis.
• This condition leads to a restrictive ischemic cardiomyopathy and heart failure in heart transplant recipients.
• Immune-mediated arterial inflammation, viral infections, and platelet hyperactivity are suspected, but not definitively quantified, contributors.