Impaired Myocardial Perfusion Reserve in Patients With Fatty Liver Disease Assessed by Quantitative Myocardial Perfusion Magnetic Resonance Imaging

Abstract

Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp onalcoholic fatty liver disease (NAFLD) is a highly prevalent condition characterized by fatty infiltration of liver cells resembling that of alcohol-induced liver injury but occurring in patients who do not abuse alcohol. 1-3 For a long time, the presence of NAFLD was considered a benign condition with little or no clinical significance. 4 However, recent results indicate that individuals with NAFLD, even without metabolic syndrome (MetS), are at high risk for coronary artery disease (CAD) 5 and the severity of the liver histology in NAFLD patients is closely associated with intima-media thickness. 2,3,6,7 Furthermore, Villanova et al showed that NAFLD is a risk factor for endothelial dysfunction, by evaluating the flowmediated vasodilatation of the brachial artery. 8 This result has stimulated interest in a possible common pathway of disease progression between fatty liver and atherosclerosis. In a recent study evaluating NAFLD patients in Europe, abnormal coronary flow reserve was found in 42% of patients without clinical signs of CAD, by using transthoracic Doppler harmonic echocardiography. 9 However, no data are currently available regarding the relationship between fatty liver and altered myocardial perfusion reserve (MPR) in the Japanese population. First-pass contrast-enhanced myocardial perfusion magnetic resonance imaging (MRI) has emerged as a method of detecting the presence and measuring the extent of hypoperfusion caused by flow-limiting CAD. 10-16 Stress-rest perfusion MRI may also provide a more objective evaluation of altered MPR in subjects with flow-limiting CAD and of microcirculation dysfunction in patients without flow-limiting epicardial coronary artery stenosis, through quantitative evaluation of myocardial blood flow (MBF), and by analysis of the myocardial and blood signal intensity time curves. 17,18 Accordingly, the purpose of our study was to determine whether the presence of a fatty liver on abdominal computed tomography (CT) is associated with alteration of MPR in subjects without flow-limiting CAD Motonori Nagata, MD; Tairo Kurita, MD; Tomomi Yamada, PhD; Kakuya Kitagawa, MD; Kaoru Dohi, MD; Mashio Nakamura, MD; Hajime Sakuma, MD; Masaaki Ito, MDBackground: The purpose of this study was to determine whether the presence of fatty liver is associated with an alteration in myocardial perfusion reserve (MPR).

Hepatic function and the cardiometabolic syndrome

“…Despite similar myocardial blood flow, it appears that myocardial blood reserve is diminished in subjects with fatty liver, whereby the coronary microcirculation becomes impaired 69. There exists a well known (bidirectional?)…”

Cardiac structure and function are altered in type 2 diabetes and Non-alcoholic fatty liver disease and associate with glycemic control

“…These cardiac changes have been associated with myocardial steatosis [ 16 ], michondondrial dysfunction [ 17 ], changes in calcium regulation, and myocardial fibrosis [ 18 ]. NAFLD is also characterized by a similar pattern of diastolic dysfunction [ 19 , 20 ], altered left ventricular geometry [ 19 ], reduced myocardial perfusion reserve [ 21 ] and changes in cardiac strain [ 22 ]. Although a growing body of epidemiological and clinical evidence links the disease processes of Type 2 diabetes and NAFLD, little is known about how these conditions may differentially affect the heart.…”

Coronary Flow Reserve Evaluated by Quantitative Perfusion Magnetic Resonance Imaging in Patients With Nonalcoholic Fatty Liver Disease

“…9 The high accuracy and reproducibility of perfusion MRI for the diagnosis of coronary stenosis and evaluation of the severity of illness has been established, and a recent randomized trial has also demonstrated that the diagnostic usefulness of perfusion MRI is superior to that of SPECT. 10 Moreover, perfusion MRI has been established by Sakuma's group as a methodologically satisfactory and accurate tool for quantitative evaluation of coronary blood flow.…”

“…Subjects with NAFLD also had a higher prevalence of MPR <2.5. 9 There are numerous mechanisms that may explain the impaired MPR in patients with NAFLD, including endothelial dysfunction, 13 type 2 diabetes, systemic inflammation, 14 insulin resistance, 15 hyperglycemia, hypertension, etc. Among these, the authors consider systemic inflammation and oxidant stress as significant mechanisms underlying the impaired MPR in patients with a fatty liver, because these 2 factors are common background factors for NAFLD and CAD, and further examination is needed.…”