Related Experiment Video
Updated: Jun 8, 2026
Retrograde Perfusion and Filling of Mouse Coronary Vasculature as Preparation for Micro Computed Tomography Imaging
Published on: February 10, 2012
Coronary microvascular dysfunction by positron emission tomography and outcomes in patients after cardiac
Bryan Abadie1, Yasmine Elghoul1, Sakthi Surya Prakash1
1Department of Cardiovascular Medicine, Heart, Vascular, and Thoracic Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, J1-5 Main Campus, Cleveland, OH 44195, USA.
Insights
In cardiac transplant recipients without cardiac allograft vasculopathy (CAV), endogen/functional coronary microvascular dysfunction (CMD) identified by PET/CT is linked to increased mortality and adverse events. Classical/structural CMD did not show this association, suggesting PET/CT can refine risk stratification.
Area of Science:
- Cardiology
- Transplant Medicine
- Medical Imaging
Background:
- Cardiac allograft vasculopathy (CAV) impacts epicardial and microvascular coronary arteries.
- Microvascular dysfunction in CAV is understudied.
- PET/CT can screen for epicardial CAV, but implications of microvascular dysfunction without epicardial CAV are unclear.
Purpose of the Study:
- To assess the prognostic significance of microvascular dysfunction subtypes using PET/CT.
- To evaluate endogen/functional and classical/structural CMD in cardiac transplant patients without epicardial CAV.
Main Methods:
- 356 transplant patients without prior CAV and normal perfusion imaging were analyzed.
- Coronary microvascular dysfunction (CMD) defined as myocardial flow reserve < 2.0.
- CMD subcategorized into endogen/functional (stress MBF ≥ 1.7) and classical/structural (stress MBF < 1.7).
Main Results:
- 141 patients (39.6%) had CMD: 112 (31.4%) endogen/functional, 29 (8.1%) classical/structural.
- Endogen/functional CMD associated with higher composite outcome (HR 2.39) and mortality (HR 2.98).
- Classical/structural CMD showed no significant association with outcomes.
Conclusions:
- Endogen/functional CMD in transplant patients without epicardial CAV predicts adverse events and mortality.
- Classical/structural CMD pattern did not correlate with poor prognosis.
- Integrating endogen/microvascular dysfunction assessment into PET/CT reporting can identify higher-risk patients.
Aims:
Cardiac allograft vasculopathy (CAV) affects both epicardial and microvascular coronary arteries, however, few studies have characterized microvascular dysfunction in this population. Several prior studies have shown that positron emission tomography/computed tomography (PET/CT) can be used to screen for epicardial CAV, however, the clinical implications of abnormal blood flow in the absence of epicardial CAV are unknown. Our study sought to assess the prognostic implications of microvascular dysfunction and its subtypes, endogen/functional and classical/structural, using PET/CT in cardiac transplant patients without epicardial CAV.
Methods And Results:
Transplant patients with no prior history of CAV and normal myocardial perfusion imaging were included. Patients were then classified by the presence of coronary microvascular dysfunction (CMD) (myocardial flow reserve < 2.0); patients with CMD were further subcategorized into endogen/functional (stress myocardial blood flow ≥ 1.7 mL/min/g) and classical/structural (stress myocardial blood flow < 1.7 mL/min/g). The primary outcomes were all-cause mortality and a composite of all-cause mortality, heart failure hospitalization, acute coronary syndrome, revascularization, and re-transplantation. Three hundred fifty-six patients met the inclusion criteria. CMD was present in 141 (39.6%) patients, of which 112 (31.4%) had endogen/functional CMD and 29 (8.1%) had classical/structural CMD. After multivariable adjustment, endogen/functional CMD was associated with a higher rate of the composite outcome (HR 2.39, 95% CI 1.32-4.29, P = 0.004) and all-cause mortality (HR 2.98, 95% CI 1.34-6.64, P = 0.008). Classical/structural CMD was not associated with the primary composite outcome (HR 0.92, 95% CI 0.27-3.17, P = 0.893) or all-cause mortality (HR 1.22, 95% CI 0.263-5.69, P = 0.797).
Conclusion:
In cardiac transplant patients with no history of CAV and normal myocardial perfusion, an endogen/functional pattern of CMD is associated with higher rate of adverse events and death. This association was not present in patients with a classical/structural CMD pattern. Incorporating endogen/microvascular dysfunction assessment in PET/CT reporting may identify a higher-risk group hereto now considered low risk.
More Related Videos
08:13In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography
Published on: February 16, 2016
08:35Oxygenation-sensitive Cardiac MRI with Vasoactive Breathing Maneuvers for the Non-invasive Assessment of Coronary Microvascular Dysfunction
Published on: August 17, 2022
