Impact of acute pulmonary rejection on cardiac function

Area of Science:

• Cardiovascular Physiology
• Transplantation Immunology
• Surgical Research

Background:

• Investigating cardiac function during acute lung allograft rejection is crucial for understanding post-transplant complications.
• Defining the impact of allograft rejection on recipient cardiac performance is essential.

Purpose of the Study:

• To assess cardiac function in dogs experiencing acute rejection of a single lung allograft.
• To evaluate changes in coronary artery dimensions during lung allograft rejection.

Main Methods:

• Adult mongrel dogs underwent lung autotransplantation or allotransplantation with triple-drug immunosuppression.
• Rejection was induced by discontinuing immunosuppression in a subset of allotransplanted animals.
• Cardiac function was assessed using computed tomography, ventricular pressure measurements, and hemodynamic calculations.

Main Results:

• Acutely rejecting lung allografts significantly depressed left ventricular contractility (systolic elastance) and ejection fraction by approximately 50%.
• Coronary artery cross-sectional area was reduced in autotransplanted and immunosuppressed allotransplanted groups compared to controls.
• Further significant reduction in coronary artery size was observed in the rejecting group.

Conclusions:

• Acute lung allograft rejection adversely affects cardiac performance, specifically contractility and ejection fraction.
• Lung allograft rejection is associated with a reduction in coronary artery diameter.
• Humoral factors and activated leukocytes likely contribute to the observed cardiac and vascular changes.