Lima, Bruno Bezerra; Doan, Tam T.; Feher, Atila; Wilkinson, James C.; Kronenberg, Marvin W.; Carr, Chloe; Nayfeh, Malek; Ruiz, Tania; Laws, Luke L.; Silva, Melissa Lou; Wells, John A.; Slipczuk, Leandro; Lippincott, Emily T.; Carr, John J.; Amonchare, Mili Kashish; Henry, Cameron; Parra, David; Schlendorf, Kelly; Wells, Quinn S.; Hughes, Sean G.; Soslow, Jonathan (2025).听.听Journal of the American Heart Association, 15(6), 1鈥�18.听
Heart transplantation can greatly improve survival and quality of life for people with severe heart failure, but long-term success is still limited by immune-related complications. Two major problems are聽acute rejection聽(when the body鈥檚 immune system attacks the new heart, usually early after surgery) and聽cardiac allograft vasculopathy (CAV)聽(a form of blood vessel disease that develops over time in the transplanted heart). Traditionally, doctors diagnose these conditions using聽endomyocardial biopsy聽(taking small tissue samples from the heart) and聽coronary angiography聽(imaging the heart鈥檚 blood vessels), but both are invasive procedures and not always perfectly reliable.
Because of this, there is growing interest in聽noninvasive imaging techniques聽that can assess the heart without surgery. For example,聽echocardiography聽(ultrasound imaging of the heart) can detect early signs of dysfunction using a method called聽strain, which measures how heart muscle deforms during contraction, even when standard measures like ejection fraction still appear normal. When combined with stress testing, it can also help predict the presence of CAV. More advanced methods, such as聽positron emission tomography (PET)听补苍诲听cardiac magnetic resonance (CMR)聽imaging, can measure blood flow in the heart more precisely and detect subtle, widespread changes associated with different stages of CAV. CMR can also identify tissue changes like聽edema聽(swelling) and聽fibrosis聽(scarring), which are important for monitoring rejection. Another emerging technique,聽FDG-PET, aims to detect inflammation but is still mostly used in research settings.
Cardiac computed tomography angiography (CCTA)聽provides detailed images of the heart鈥檚 blood vessels and can assess both structure and function, making it useful for evaluating CAV, though it is best used selectively rather than as a routine yearly test. Overall, this review highlights how combining multiple imaging approaches can improve detection and monitoring of transplant-related complications. By reducing the need for repeated invasive procedures, these methods can lower risk and help doctors make better treatment decisions鈥攁n especially important benefit for children and other patients who may be more vulnerable to the downsides of invasive testing.
Figure 1. Quantitative cardiac magnetic resonance perfusion analysis in a patient with orthotopic heart transplantation and cardiac allograft vasculopathy.
Left, rest and stress first鈥恜ass perfusion images show myocardial segmentation for blood pool (yellow), endocardium (red), and epicardium (green) regions of interest.听Middle, corresponding time鈥搒ignal intensity curves for blood pool and myocardium are plotted at rest (top) and stress (bottom), with slopes derived for quantitative myocardial blood flow estimation.听Right, the bull鈥檚鈥恊ye plot demonstrates globally reduced myocardial perfusion reserve index, with values ranging from 1.3 to 1.7, consistent with diffuse impairment of coronary flow reserve in advanced CAV. CAV indicates cardiac allograft vasculopathy; and MPRi, myocardial perfusion reserve index.