scholarly journals Impact of obesity on myocardial microvasculature assessed using fully-automated inline myocardial perfusion mapping CMR

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
G Joy ◽  
JD Crane ◽  
C Lau ◽  
J Augusto ◽  
LAE Brown ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Guy"s and St Thomas" Charity University College London Hospitals Biomedical Research Centre Background Obesity and cardiovascular disease are associated, but the relationship is poorly understood. Myocardial perfusion, metabolic derangement and lipotoxicity appear adversely associated in many scenarios (myocardial injury, diastolic dysfunction, diabetes). Altered perfusion (by PET) predicts outcome, and it is hypothesised that perfusion derangement is part of causality for cardiac disease and adverse outcomes. Purpose To assess the presence and pattern of myocardial microvascular dysfunction in patients with obesity (scheduled for bariatric surgery) using stress quantitative perfusion mapping. Methods 38 subjects with obesity planned to undergo bariatric surgery and 38 age and sex matched healthy volunteers (no diabetes, no hypertension) underwent anthropometry, biochemistry and CMR at 1.5T (Siemens) with cine imaging, stress (adenosine 140-210 mcg/kg/min) and rest fully-automated quantitative perfusion mapping.  Results Bariatric patients had a higher BMI (44 ± 6.4 vs 26.5 ± 4kg/m2 p = 0.001); 58%(22) were diabetic and 58%(22) had hypertension. Bariatric patients had higher absolute but lower indexed end-diastolic volumes, and overall higher ejection fractions (+5%) (see Table). Rest myocardial blood flow (MBF) in bariatric patients was the same (1.00 ± 0.3 vs 0.88 ± 0.24 p = 0.052), but stress perfusion results were significantly lower both for stress MBF (2.35 ± 0.69 vs 2.93 ± 0.76ml/g/min p = 0.001) and myocardial perfusion reserve (MPR 2.48 ± 0.82 vs 3.4 ± 0.81ml/g/min p = 0.0001).  Although this was transmural, the endocardial stress MBF was particularly negatively affected in the bariatric cohort compared to controls (endocardial MBF 2.16 ± 0.65 vs 2.82 ± 0.73ml/g/min, p = 0.0001 vs epicardial MBF: 2.52 ± 0.76 vs 3.06 ± 0.79 p = 0.003), meaning there was an increased endo-epicardial stress MBF gradient in bariatric patients (0.87 ± 0.12 vs 0.92 ± 0.07 p = 0.03). Conclusion Compared to healthy controls, patients with obesity have abnormal myocardial stress perfusion with reduced global perfusion, perfusion reserve and an increased transmyocardial perfusion gradient. Table - myocardial perfusion parameters Category Bariatric patients n = 38 Controls n = 38 p value Age (years) 48 ± 11 45 ± 13 0.25 n male (%) 12 (32%) 10 (36%) 0.32 LVEDV (ml) 168 ± 37 149 ± 31 0.017 LVEDVi (ml/m2) 70.4 ± 12.3 78.8 ± 12.1 0.004 LV Mass (g) 116 ± 31 99 ± 28 0.019 EF (%) 70 ± 8 65 ± 5 0.002 LVEDV - left ventricular end-diastolic volume, EF - ejection fraction

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
G Joy ◽  
JD Crane ◽  
JB Augusto ◽  
C Lau ◽  
A Seraphim ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Guy"s and St Thomas" Charity University College London Hospital Biomedical Research Centre Background   In people with obesity, bariatric surgery reduces mortality, heart failure and coronary disease, improving metabolic (blood sugar, lipid profile, inflammation) and cardiovascular (diastolic/systolic function, filling pressure, cardiac remodelling) parameters. Myocardial microvascular function is a candidate causal link of metabolic to structural cardiac abnormalities. Purpose We hypothesised that bariatric surgery could improve myocardial microvascular and mechanical function in both those with and without diabetes.  Methods Before and six months after bariatric surgery, 24 subjects with obesity were assessed with haematology, biochemistry and advanced CMR (cines, vasodilator adenosine stress and rest fully-automated quantitative perfusion mapping, tissue-tracking (CVI42, post processing).  Results. Mean age was 49± 12 years, 35%(8) were male, 63%(15), had hypertension, 17 (71%) had diabetes. Surgery resulted in decreases in BMI (44 ± 7 to 34 ± 6 kg/m2 p = 0.0001) and HbA1c (57 ± 16 to 42 ± 9mmol/mol p = 0.0001). EF% and absolute LV end-diastolic volumes remained unchanged, but mass regressed and myocardial contraction fraction (ratio of stroke volume and LV volume) increased (see Table).  There were also strain improvements (radial 35 ± 8.8 to 37.3 ± 8.7 %p = 0.029) (circumferential -19.8 ± 2.3 vs -20.7 ± 3% p = 0.017), although longitudinal did not improve (-16.3 ± 3.2 to -15.9 ± 3% p = 0.25). Myocardial perfusion significantly improved (stress myocardial blood flow, MBF 2.35 ± 0.71 to 2.80 ± 0.98 ml/g/min p = 0.008; myocardial perfusion reserve MPR 2.47 ± 0.78 to 2.97 ± 0.95 p = 0.005).  Improvement in stress MBF and MPR from pre-operative to post-operative was higher in the non-diabetics (n = 7 (29%)) than the diabetics (n = 17 (71%)) (stress MBF: 1.15 ± 1.00 vs 0.16 ± 0.39ml/g/min p = 0.002) MPR: (1.09 ± 0.73 vs 0.25 ± 0.66 p = 0.011). Conclusion At 6 months, bariatric surgery results in beneficial myocardial remodelling and substantial improvements in myocardial microvascular function. These improvements occur most in those without diabetes suggesting that there may be reversible and irreversible components to microvascular dysfunction. Perfusion and strain variables Variable Pre-op (n = 24) Post-op (n = 24) p-value LVEDV (ml) 163 ± 28 161 ± 29 0.64 EF (%) 70 ± 8 70 ± 7 0.78 Stroke volume (ml) 113 ± 19 111 ± 21 0.6 LV Mass (g) 117 ± 25 103 ± 21 0.001 Myocardial contraction fraction 94 ± 14 105 ± 14 0.001 LVEDV - left ventricular end-diastolic volume, EF - ejection fraction Abstract Figure.


2021 ◽  
Author(s):  
Benjamin Stillhard ◽  
B. T. Truc Ngo ◽  
Ralph Peterli ◽  
Thomas Peters ◽  
Romano Schneider ◽  
...  

Abstract Purpose The combination of obesity and diabetes mellitus are well-known risk factors for cardiovascular complications and perioperative morbidity in metabolic surgery. The aim of this study was to evaluate effectivity and reliability of the cardiac assessment in patients with diabetes prior to bariatric surgery. Setting Private, university-affiliated teaching hospital, Switzerland Material and Methods Retrospective analysis of prospectively collected data on results and consequences of cardiac assessments in 258 patients with obesity and diabetes scheduled for primary bariatric surgery at our institution between January 2010 and December 2018. Results Out of 258 patients, 246 (95.3%) received cardiac diagnostics: 173 (67.1%) underwent stress-rest myocardial perfusion scintigraphy (MPS), 15 (5.8%) patients had other cardiac imaging including cardiac catheterization, 58 (22.5%) patients had echocardiography and/or stress electrocardiography, and 12 (4.7%) patients received no cardiac evaluation. Subsequently, cardiac catheterization was performed in 28 patients (10.9%), and coronary heart disease was detected and treated in 15 subjects (5.8%). Of these 15 individuals, 5 (33.3%) patients had diffuse vascular sclerosis, 8 (53.3%) patients underwent coronary angioplasty and stenting, and 2 (13.3%) patients coronary artery bypass surgery. Bariatric surgery was performed without perioperative cardiovascular events in all 258 patients. Conclusion Our data suggest that a detailed cardiac assessment is mandatory in bariatric patients with diabetes to identify those with yet unknown cardiovascular disease before performing bariatric surgery. We recommend carrying out myocardial perfusion scintigraphy as a reliable diagnostic tool in this vulnerable population. If not viable, stress echocardiography should be performed as a minimum.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Eduard I Dedkov ◽  
Yevgen Bogatyryov ◽  
Daniela McCooey ◽  
Lance P Christensen ◽  
Robert J Tomanek

Background: We have previously shown that 1-month treatment with ivabradine (IVA), the selective cardiac pacemaker I f current inhibitor, preserved myocardial perfusion and coronary perfusion reserve in post-MI middle-aged rats. However, the persistence of this cardioprotective effect after a prolonged period of IVA treatment remains to be determined. Methods: Acute MI was induced in 12-month-old male Sprague-Dawley rats by left coronary artery ligation. Twenty four hours later, the rats with a confirmed large transmural MI (>50% of the left ventricular (LV) free wall) were randomly assigned in two experimental groups. In a first group, rats were treated with IVA i.p. via osmotic pumps in a dose of 10.5 mg/kg/day for 3 months (MI+IVA). In a second group, rats received placebo treatment (5% dextrose) during the same time period (MI). Sham-operated rats served as an age-matched control. At the end of experimental period, myocardial perfusion (baseline and maximal coronary conductance per 100g of tissue) and coronary perfusion reserve (fold increase between baseline and maximal coronary conductance) were determined in non-infarcted LV free wall and interventricular septum by using the neutron-activated stable isotope-labeled microsphere technique. Results: During 3 months of IVA treatment, heart rate in MI+IVA rats was consistently reduced compared to untreated MI rats by mean of 30.6%. Nevertheless, we found that the infarct size and the extent of LV remodeling were relatively comparable between MI and MI+IVA rats three months after surgery. Moreover, the levels of baseline and maximal coronary conductance were similar in LV free wall and septum between two experimental groups. Consequently, IVA-treated rats revealed no difference in coronary perfusion reserve as compared to untreated post-MI animals (2.22±0.46 vs. 2.59±0.41 in LV free wall and 2.30±0.59 vs. 2.68±0.44 in septum, respectively). However, the rats of both post-MI groups had markedly reduced levels of maximal coronary blood flow as compared to non-infarcted controls (p≤0.01). Conclusion: Our data demonstrate that long-term IVA treatment does not provide sustainable improvement in LV myocardial perfusion and coronary perfusion reserve in middle-aged rats following large MI.


2021 ◽  
Vol 8 ◽  
Author(s):  
George D. Thornton ◽  
Abhishek Shetye ◽  
Dan S. Knight ◽  
Kris Knott ◽  
Jessica Artico ◽  
...  

Background: Acute myocardial damage is common in severe COVID-19. Post-mortem studies have implicated microvascular thrombosis, with cardiovascular magnetic resonance (CMR) demonstrating a high prevalence of myocardial infarction and myocarditis-like scar. The microcirculatory sequelae are incompletely characterized. Perfusion CMR can quantify the stress myocardial blood flow (MBF) and identify its association with infarction and myocarditis.Objectives: To determine the impact of the severe hospitalized COVID-19 on global and regional myocardial perfusion in recovered patients.Methods: A case-control study of previously hospitalized, troponin-positive COVID-19 patients was undertaken. The results were compared with a propensity-matched, pre-COVID chest pain cohort (referred for clinical CMR; angiography subsequently demonstrating unobstructed coronary arteries) and 27 healthy volunteers (HV). The analysis used visual assessment for the regional perfusion defects and AI-based segmentation to derive the global and regional stress and rest MBF.Results: Ninety recovered post-COVID patients {median age 64 [interquartile range (IQR) 54–71] years, 83% male, 44% requiring the intensive care unit (ICU)} underwent adenosine-stress perfusion CMR at a median of 61 (IQR 29–146) days post-discharge. The mean left ventricular ejection fraction (LVEF) was 67 ± 10%; 10 (11%) with impaired LVEF. Fifty patients (56%) had late gadolinium enhancement (LGE); 15 (17%) had infarct-pattern, 31 (34%) had non-ischemic, and 4 (4.4%) had mixed pattern LGE. Thirty-two patients (36%) had adenosine-induced regional perfusion defects, 26 out of 32 with at least one segment without prior infarction. The global stress MBF in post-COVID patients was similar to the age-, sex- and co-morbidities of the matched controls (2.53 ± 0.77 vs. 2.52 ± 0.79 ml/g/min, p = 0.10), though lower than HV (3.00 ± 0.76 ml/g/min, p< 0.01).Conclusions: After severe hospitalized COVID-19 infection, patients who attended clinical ischemia testing had little evidence of significant microvascular disease at 2 months post-discharge. The high prevalence of regional inducible ischemia and/or infarction (nearly 40%) may suggest that occult coronary disease is an important putative mechanism for troponin elevation in this cohort. This should be considered hypothesis-generating for future studies which combine ischemia and anatomical assessment.


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