RT Journal Article
SR Electronic
T1 Characterization of Myocardial Blood Flow in End Stage Liver Disease Patients Undergoing Liver Transplant Evaluation
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 162
OP 162
VO 60
IS supplement 1
A1 Kelly Shum
A1 Joseph Englert
A1 Merrill Stewart
A1 Nichole Polin
A1 Daniel Morin
A1 Robert Bober
YR 2019
UL http://jnm.snmjournals.org/content/60/supplement_1/162.abstract
AB 162Objectives: Stress myocardial blood flow (sMBF) and coronary flow reserve (CFR) by cardiac positron emission tomography (cPET) have been shown to provide prognostic information supplemental to relative perfusion images. However, myocardial blood flow (MBF) has not been characterized in patients with end stage liver disease (ESLD). Characterization of MBF may provide additional physiologic information to further assist with management and risk stratification for patients undergoing liver transplantation. Methods: A total of 126 patients with ESLD undergoing liver transplant evaluation that underwent rubidium-82 cPET with dipyridamole stress were retrospectively identified. The ESLD patients were compared to 120 age and gender matched controls that underwent cPET stress testing with dipyridamole for clinically indicated purposes. In both groups, studies with significant perfusion abnormalities were excluded. A significant perfusion abnormality was defined as a >10% and >5% contiguous area of LV myocardial perfusion defect on rest and stress imaging, respectively, with activity ≤60% of maximum. By this method, all patients in both groups demonstrated normal relative rest and stress perfusion images. Results: The median age for ESLD and control patients was 60 years old (IQR: 55-65) and 61 years old (IQR: 54-67), (p=0.894), respectively. There were 64% and 70% males in the ESLD and control group, respectively (p=0.344). The ESLD cohort had lower rates of hypertension (37.3% vs 68.3%, p=<0.001) and hyperlipidemia (11.9% vs 60.0%, p<0.001), while having similar rates of diabetes mellitus type 2 (39.7% vs 39.2%, p=1.000) and tobacco use (7.1% vs 8.3%, p=0.813). The ESLD cohort also had a median lower BMI compared to the control group (28.9 (IQR: 25.1-33.6) vs. 33.5 (IQR: 29.3-39.2), p<0.001). The ESLD patients had higher median resting MBF (rMBF) (1.01 cc/min/g; IQR (0.83-1.33) vs. 0.85 cc/min/g; IQR (0.85-1.10), p<0.001], lower median sMBF [1.46 cc/min/g; IQR (1.21-1.88) vs. 1.71 cc/min/g; IQR (1.42-2.25), p<0.001], and lower median CFR [1.39 (IQR: 1.14-1.74) vs. 2.08 (IQR=1.76-2.44), p<0.001]. This pattern of elevated rMBF, lower sMBF, and lower CFR in ESLD patients remained statistically significant when adjusted for their resting rate pressure products. Conclusions: Despite having fewer cardiac risk factors, patients with ESLD have higher rMBF, lower sMBF and lower CFR when compared to age and gender matched control patients. The physiologic mechanisms for these findings are unclear, but the elevated rMBF could stem from physiologic shunting such as in hepatopulmonary syndrome. Reduced sMBF and CFR may be related to either a resistance to dipyridamole or due to an unexplained mechanism preventing increase in sMBF and CFR. Further investigation into this population is warranted.