Quantitative Perfusion

1356990 - Quantitative Perfusion in Heart Transplant Patients with Cardiac Allograft Vasculopathy

Wednesday, January 25, 2023

Location: E-POSTER

Presenting Author(s)

JB

Jay B. Bisen, BSc

Medical Student
Northwestern University, United States

Primary Author(s)

JB

Jay B. Bisen, BSc

Medical Student
Northwestern University, United States

Co-Author(s)

SQ

Sandra Quinn, BSc, MB BCh BAO, PhD

Clinical Research Associate
Northwestern University
Chciago, Illinois, United States
OK

Ozden Kilinc, MD

Clinical Research Associate
Northwestern University
Chicago, Illinois, United States
KC

Kelvin Chow, PhD

Staff Scientist
Siemens Healthineers
Chicago, Illinois, United States
RD

Rachel Davids

Clinical Applications Scientist
Siemens Medical Solutions USA, Inc., Illinois, United States
Daniel C. Lee, MD

Associate Professor of Medicine (Cardiology) and Radiology
Northwestern University
Chicago, Illinois, United States
DK

Dan Kim, MD, MS

Cardiology Fellow
Loyola University Medical Center
Streamwood, Illinois, United States
RW

Richard Weinberg, MD, PhD

Assistant Professor of Medicine (Cardiology)
Northwestern University, United States
James Carr, MD

Professor
Northwestern University
Chicago, Illinois, United States
Bradley D. Allen, MD, MSc, FSCMR

Assistant Professor, Cardiovascular and Thoracic Imaging
Northwestern University
Chicago, Illinois, United States
RA

Ryan Avery, MD, MD

Assistant Professor of Radiology (Nuclear Medicine), Chief of Nuclear Medicine
Northwestern University
Chicago, Illinois, United States

Disclosure(s):

Daniel C. Lee, MD: No relevant disclosure to display

James Carr, MD: No relevant disclosure to display

Bradley D. Allen, MD, MSc, FSCMR: No relevant disclosure to display

Background: Heart transplantation is the primary treatment for end-stage heart failure. Cardiac Allograft Vasculopathy (CAV) is a form of accelerated intimal hyperplasia that limits long-term survival. Improved noninvasive techniques are needed for early-stage CAV surveillance to guide treatment. Quantitative perfusion imaging (QP) is an emerging CMR technique to characterize obstructive coronary disease and microvascular dysfunction. QP provides voxel-wise quantification of myocardial blood flow (MBF), and the myocardial perfusion reserve (MPR) can be calculated with stress and rest imaging. We hypothesize that QP-determined differences in MBF and MPR could assess CAV severity in heart transplant patients.

Methods: Ten patients who underwent the same QP CMR pulse sequence were retrospectively analyzed (46 ± 17 years; 60% male) to assess differences between CAV-positive (CAV+) and CAV-negative (CAV-) patients. For comparison of global values with CAV status, CAV+ was defined as moderate or severe CAV whereas CAV- was defined as no or mild CAV. Grading of CAV was as per ISHLT criteria. For individual epicardial artery and associated myocardial territory analysis, vessels were grouped into those with angiographic evidence of flow-limiting disease ( >70% stenosis) in major vessels or associated branches, and without (< 50% stenosis).
Five CAV+ subjects were matched to CAV- subjects based on age, gender, time between transplant and scan, and age at transplant. QP imaging was performed using a prototype dual-sequence acquisition with inline quantification on a 1.5T system (MAGNETOM Avanto, Siemens Healthcare, Germany) at rest and with 140 μg/kg/min of adenosine stress.
Data was analyzed by the same observer (cvi42, Calgary) to attain global, LAD, LCx, and RCA MBF at rest and stress as well as MPR values. Comparisons were made between CAV+/- patients and between regions corresponding to vessels with stenosis >70% (n=8) and < 50% stenosis vessels (n=22). Statistical comparisons were performed using independent t-tests.

Results: CAV+ patients presented with lower global MPR values than CAV- patients (2.12 vs 3.61 respectively, p=0.03), consistent with lower MPR values in CAV+ vessels (2.01 vs 3.19, p=0.02) (Figure). Territories with epicardial artery stenosis > 70% had both higher rest MBF (2.04 vs 1.02 mL/g/min, p=0.00) and stress MBF (3.72 vs 3.05 mL/g/min, p=0.05) compared with those without significant stenosis.

Conclusion: QP is a promising approach to characterize myocardial perfusion in transplant patients at risk of CAV. Significant reductions in myocardial flow related to CAV were observed, with greater changes in global and regional MPR than rest or stress MBF alone.
Further study on a larger cohort to assess the clinical role of QP for cardiac transplant patients is needed to explore correlations between abnormal MPR and CAV severity and to correlate with other imaging modalities.