American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the most common cause of reduced left ventricular function in heart transplant patients after the first year?

1. Myocardial infarction

2. Cardiac allograft vasculopathy

3. Coronary artery disease

4. Heart failure

The correct answer is: Cardiac allograft vasculopathy

The most common cause of reduced left ventricular function in heart transplant patients after the first year is cardiac allograft vasculopathy. This condition is a specific form of coronary artery disease that affects transplanted hearts. Unlike typical coronary artery disease, which can result from traditional risk factors, cardiac allograft vasculopathy is characterized by transplant-specific factors, such as chronic rejection and immunological responses to the donor heart. The pathophysiology involves progressive intimal thickening of the coronary arteries, leading to ischemia and impaired function of the transplanted heart. This process typically unfolds silently and can significantly compromise cardiac output without the typical symptoms one might expect from coronary artery disease in non-transplant patients. Monitoring and early detection of this condition are crucial for managing transplant recipients effectively, especially as they enter the late post-transplant phase. While myocardial infarction, coronary artery disease, and heart failure can certainly contribute to reduced left ventricular function, they are not as specific or prevalent in the unique setting of heart transplantation after the initial year. Cardiac allograft vasculopathy stands out as a distinct and critical consequence of transplantation that specifically affects long-term outcomes in heart transplant patients.