Thoracic Aortic Volume as a Predictor of Cardiovascular Events: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: It is unclear whether thoracic aortic volume (TAV) is useful for cardiovascular (CV) disease prognosis and risk assessment. PURPOSE: This study evaluated cross-sectional associations of TAV with CV risk factors, and longitudinal association with incident CV events in the multiethnic study of atherosclerosis. STUDY TYPE: Retrospective cohort analysis of prospective data. POPULATION: 1182 participants (69 ± 9 years, 54% female, 37% Caucasian, 18% Chinese, 31% African American, 14% Hispanic, 60% hypertensive, and 20% diabetic) without prior CV disease. FIELD STRENGTH AND SEQUENCES: Axial black-blood turbo spin echo or bright blood steady-state free precession images on 1.5T scanners. ASSESSMENT: TAV was calculated using Simpson's method from axial images, and included the ascending arch and descending segments. Traditional CV risk factors were assessed at the time of MRI. CV outcomes over a 9-year follow-up period were recorded and represented a composite of stroke, stroke death, coronary heart disease (CHD), CHD death, atherosclerotic death, and CVD death. STATISTICAL TESTS: Multivariable linear regression models adjusted for height and weight were used to determine the relationship (ß coefficient) between TAV and CV risk factors. Cox regression models assessed the association of TAV and incident CV events. A P-value of <0.05 was deemed statistically significant. RESULTS: Mean TAV was = 139 ± 41 mL. In multivariable regression, TAV was directly associated with age (ß = 1.6), male gender (ß = 23.9), systolic blood pressure (ß = 0.1), and hypertension medication use (ß = 7.9); and inversely associated with lipid medication use (ß = -5.3) and treated diabetes (ß = -8.9). Compared to Caucasians, Chinese Americans had higher TAV (ß = 11.4), while African Americans had lower TAV (ß = -7.0). Higher TAV was independently associated with incident CV events (HR: 1.057 per 10 mL). CONCLUSION: Greater TAV is associated with incident CV events, increased age, and hypertension in a large multiethnic population while treated diabetes and lipid medication use were associated with lower TAV. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.

Management of Biliary Stricture in Pediatric Liver Transplantation Patients: Long-Term Outcomes.

Postoperative biliary complications have been reported to occur in 10% to 33% of pediatric liver transplantation (LT) recipients. Percutaneous intervention has become the primary treatment method for these complications; however, the efficacy and outcomes of these patients have not been well studied. Institutional pediatric LT from 1998 to 2019 were retrospectively reviewed to determine the patients referred for percutaneous treatment of post-LT biliary strictures. Clinical parameters, percutaneous transhepatic cholangiograms (PTCs), biliary catheter placement, cholangioplasty, and long-term outcomes were analyzed. Of the 396 consecutive pediatric LT recipients during our study period, 50 (12.6%) were diagnosed with biliary strictures on PTC. LT biliary reconstructions were Roux-en-Y hepaticojejunostomy in 28 patients (56%), choledochojejunostomy in 11 patients (22%), and choledochocholedochostomy in 11 patients (22%). Median age at LT was 23.2 months (interquartile range [IQR], 10.9-90.6), and 14 patients (28%) developed hepatic artery thrombosis. A total of 44 patients (88%) were treated with internal/external biliary catheters, of whom 38 (76%) underwent balloon cholangioplasty. By 12 months, 84% of patients had complete stricture resolution and catheter removal. Median total duration of catheter drainage was 152 days (IQR, 76-308). A total of 8 patients required additional surgery (biliary reconstruction or repeat LT [re-LT]) or died with a drainage catheter in place from complications unrelated to PTC intervention. Among the 6 patients (12%) treated with unilateral external biliary drainage catheters, 2 had catheters removed for inadequate drainage but then had spontaneous biliary obstruction resolution, 1 underwent duct reconstruction, and 3 required long-term catheterization. Biliary strictures following pediatric LT can be successfully treated with internal/external biliary drainage catheters and cholangioplasty if the stricture can be crossed. However, patients with isolated strictured ducts may require long-term external catheter drainage until re-LT or percutaneous obliteration of isolated ducts.

Aortic enlargement in chronic obstructive pulmonary disease (COPD) and emphysema: The Multi-Ethnic Study of Atherosclerosis (MESA) COPD study.

BACKGROUND: The prevalence of abdominal aortic aneurysm is high in chronic obstructive pulmonary disease (COPD) population. Emphysema involves proteolytic destruction of elastic fibers. Therefore, emphysema may also contribute to thoracic aorta dilatation. This study assessed aorta dilation in smokers stratified by presence of COPD, emphysema and airway thickening. METHODS: Aorta diameters were measured on 3D magnetic resonance angiography in smokers recruited from the Multi-Ethnic Study of Atherosclerosis (MESA), the Emphysema and Cancer Action Project (EMCAP), and the local community. COPD was defined by standard spirometric criteria; emphysema was measured quantitatively on computed tomography and bronchitis was determined from medical history. RESULTS: Participants (n = 315, age 58-79) included 150 with COPD and 165 without COPD, of whom 56% and 19%, respectively, had emphysema. Subjects in the most severe quartile of emphysematous change showed the largest diameter at all four aorta locations compared to those in the least severe quartiles (all p < 0.001). Comparing subjects with and without COPD, aorta diameters were larger in participants with severe COPD in ascending and arch (both p < 0.001), and abdominal aorta (p = 0.001). Chronic bronchitis and bronchial wall thickness did not correlate with aorta diameter. In subjects with emphysema, subjects with coexistence of COPD showed larger aorta than those without COPD in ascending (p = 0.003), arch (p = 0.002), and abdominal aorta (p = 0.04). CONCLUSIONS: This study showed larger aorta diameter in subjects with COPD and severe emphysema compared to COPD related to chronic bronchitis or bronchial wall thickening.

Reproducibility and Changes in Vena Caval Blood Flow by Using 4D Flow MRI in Pulmonary Emphysema and Chronic Obstructive Pulmonary Disease (COPD): The Multi-Ethnic Study of Atherosclerosis (MESA) COPD Substudy.

BackgroundChronic obstructive pulmonary disease (COPD) is associated with hemodynamic changes in the pulmonary vasculature. However, cardiac effects are not fully understood and vary by phenotype of chronic lower respiratory disease.PurposeTo use four-dimensional (4D) flow MRI for comprehensive assessment of the right-sided cardiovascular system, assess its interrater and intraobserver reproducibility, and examine associations with venous return to the right heart in individuals with chronic COPD and emphysema.Materials and MethodsThe Multi-Ethnic Study of Atherosclerosis COPD substudy prospectively recruited participants who smoked and who had COPD and nested control participants from population-based samples. Electrocardiography and respiratory gated 4D flow 1.5-T MRI was performed at three sites with full volumetric coverage of the thoracic vessels in 2014-2017 with postbronchodilator spirometry and inspiratory chest CT to quantify percent emphysema. Net flow, peak velocity, retrograde flow, and retrograde fraction were measured on 14 analysis planes. Interrater reproducibility was assessed by two independent observers, and the principle of conservation of mass was employed to evaluate the internal consistency of flow measures. Partial correlation coefficients were adjusted for age, sex, race/ethnicity, height, weight, and smoking status.ResultsAmong 70 participants (29 participants with COPD [mean age, 73.5 years ± 8.1 {standard deviation}; 20 men] and 41 control participants [mean age, 71.0 years ± 6.1; 22 men]), the interrater reproducibility of the 4D flow MRI measures was good to excellent (intraclass correlation coefficient range, 0.73-0.98), as was the internal consistency. There were no statistically significant differences in venous flow parameters according to COPD severity (P > .05). Greater percent emphysema at CT was associated with greater regurgitant flow in the superior and inferior caval veins and tricuspid valve (adjusted r = 0.28-0.55; all P < .01), particularly in the superior vena cava.ConclusionFour-dimensional flow MRI had good-to-excellent observer variability and flow consistency. Percent emphysema at CT was associated with statistically significant differences in retrograde flow, greatest in the superior vena cava.© RSNA, 2019Online supplemental material is available for this article.See also the editorial by Choe in this issue.

Prevalence of Unexplained Left Ventricular Hypertrophy by Cardiac Magnetic Resonance Imaging in MESA.

Background Hypertrophic cardiomyopathy is defined as unexplained left ventricular ( LV ) hypertrophy (wall thickness ≥15 mm) and is prevalent in 0.2% of adults (1:500) in population-based studies using echocardiography. Cardiac magnetic resonance imaging ( MRI ) allows for more accurate wall thickness measurement across the entire ventricle than echocardiography. The prevalence of unexplained LV hypertrophy by cardiac MRI is unknown. MESA (Multi-Ethnic Study of Atherosclerosis) recruited individuals without overt cardiovascular disease 45 to 84 years of age. Methods and Results We studied 4972 individuals who underwent measurement of regional LV wall thickness by cardiac MRI as part of the MESA baseline exam. American Heart Association criteria were used to define LV segments. We excluded participants with hypertension, LV dilation (≥95% predicted end-diastolic volume) or dysfunction (ejection fraction ≤50%), moderate-to-severe left-sided valve lesions by cardiac MRI , severe aortic valve calcification by cardiac computed tomography (aortic valve Agatston calcium score >1200 in women or >2000 in men), obesity (body mass index >35 kg/m2), diabetes mellitus, and current smoking. Sixty-seven participants (aged 64±10 years, 9% female) had unexplained LV hypertrophy (wall thickness ≥15 mm in at least 2 adjacent LV segments), representing 1.4% (1 in 74) participants, 2.6% of men and 0.2% of women. Prevalence was similar across categories of race/ethnicity. Hypertrophy was focal in 17 (25.4%), intermediate in 44 (65.7%), and diffuse in 5 (7.5%) participants. Conclusions The prevalence of unexplained LV hypertrophy in a population-based cohort using cardiac MRI was 1.4%. This may have implications for the diagnosis of patients with hypertrophic cardiomyopathy and will require further study.

Carotid Artery Wall Thickness and Incident Cardiovascular Events: A Comparison between US and MRI in the Multi-Ethnic Study of Atherosclerosis (MESA).

Purpose To compare common carotid artery (CCA) wall thickness measured manually by using US and semiautomatically by using MRI, and to examine their associations with incident coronary heart disease and stroke. Materials and Methods This prospective study enrolled 698 participants without a history of clinical cardiovascular disease (CVD) from the Multi-Ethnic Study of Atherosclerosis (MESA) from July 2000 to December 2013 (mean age, 63 years; range, 45 to 84 years; same for men and women). All participants provided written informed consent. CCA wall thickness was measured with US as well as both noncontrast proton-density-weighted and intravenous gadolinium-enhanced MRI. Cox proportional hazards models were used to assess the associations between wall thickness measurements by using US and MRI with CVD outcomes. Results The adjusted hazard ratios for coronary heart disease, stroke, and CVD associated with per standard deviation increase in intima-media thickness were 1.10, 1.08, and 1.14, respectively. The corresponding associations for mean wall thickness measured with proton-density-weighted MRI were 1.32, 1.48, and 1.37, and for mean wall thickness measured with gadolinium-enhanced MRI were 1.27, 1.58, and 1.38. When included simultaneously in the same model, MRI wall thickness, but not intima-media thickness, remained associated with outcomes. Conclusion For individuals without known cardiovascular disease at baseline, wall thickness measurements by using MRI were more consistently associated with incident cardiovascular disease, particularly stroke, than were intima-media thickness by using US. © RSNA, 2018 Online supplemental material is available for this article.

Pulmonary artery stiffness in chronic obstructive pulmonary disease (COPD) and emphysema: The Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study.

PURPOSE: Chronic obstructive pulmonary disease (COPD) and particularly emphysema are characterized by stiffness of the aorta, due in part to accelerated elastin degradation in the lungs and aorta. Stiffness of the pulmonary arteries (PAs) may also be increased in COPD and emphysema, but data are lacking. We assessed PA stiffness using MRI in patients with COPD and related these measurements to COPD severity and percent emphysema. MATERIALS AND METHODS: The Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study recruited 290 participants, age 50-79 years with 10 or more packyears and free of clinical cardiovascular disease. COPD severity were defined on postbronchodilator spirometry by ATS/ERS criteria. Percent emphysema was defined as the percentage of regions of the lung < -950 Hounsfield units on full-lung computed tomography (CT). PA stain was defined by the percent change in cross-sectional PA area between systole and diastole on MRI. Blood flow across the tricuspid and mitral valves was assessed by phase-contrast MRI for determination of the ventricular diastolic dysfunction (E/A ratio). RESULTS: PA strain was reduced in COPD compared with controls (P = 0.002) and was inversely correlated with COPD severity (P = 0.004). PA strain was inversely associated to percent emphysema (P = 0.01). PA strain was also markedly correlated with right ventricular diastolic dysfunction measured by E/A ratios in the fully adjusted mix models (P = 0.02). CONCLUSION: PA strain is reduced in COPD, related in part to percent emphysema on CT scan, which may have implications for pulmonary small vessel flow and right ventricular function. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:262-271.

Cardiovascular Event Prediction by Machine Learning: The Multi-Ethnic Study of Atherosclerosis.

RATIONALE: Machine learning may be useful to characterize cardiovascular risk, predict outcomes, and identify biomarkers in population studies. OBJECTIVE: To test the ability of random survival forests, a machine learning technique, to predict 6 cardiovascular outcomes in comparison to standard cardiovascular risk scores. METHODS AND RESULTS: We included participants from the MESA (Multi-Ethnic Study of Atherosclerosis). Baseline measurements were used to predict cardiovascular outcomes over 12 years of follow-up. MESA was designed to study progression of subclinical disease to cardiovascular events where participants were initially free of cardiovascular disease. All 6814 participants from MESA, aged 45 to 84 years, from 4 ethnicities, and 6 centers across the United States were included. Seven-hundred thirty-five variables from imaging and noninvasive tests, questionnaires, and biomarker panels were obtained. We used the random survival forests technique to identify the top-20 predictors of each outcome. Imaging, electrocardiography, and serum biomarkers featured heavily on the top-20 lists as opposed to traditional cardiovascular risk factors. Age was the most important predictor for all-cause mortality. Fasting glucose levels and carotid ultrasonography measures were important predictors of stroke. Coronary Artery Calcium score was the most important predictor of coronary heart disease and all atherosclerotic cardiovascular disease combined outcomes. Left ventricular structure and function and cardiac troponin-T were among the top predictors for incident heart failure. Creatinine, age, and ankle-brachial index were among the top predictors of atrial fibrillation. TNF-α (tissue necrosis factor-α) and IL (interleukin)-2 soluble receptors and NT-proBNP (N-Terminal Pro-B-Type Natriuretic Peptide) levels were important across all outcomes. The random survival forests technique performed better than established risk scores with increased prediction accuracy (decreased Brier score by 10%-25%). CONCLUSIONS: Machine learning in conjunction with deep phenotyping improves prediction accuracy in cardiovascular event prediction in an initially asymptomatic population. These methods may lead to greater insights on subclinical disease markers without apriori assumptions of causality. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00005487.

Comparison of Triple-Drug Transcatheter Arterial Chemoembolization (TACE) With Single-Drug TACE Using Doxorubicin-Eluting Beads: Long-Term Survival in 313 Patients.

OBJECTIVE: We compared survival outcomes in 313 patients with unresectable hepatocellular carcinoma (HCC) treated with two different transcatheter arterial chemoembolization (TACE) regimens: triple-drug TACE or single-drug TACE using drug-eluting beads. MATERIALS AND METHODS: In this retrospective study, patient selection criteria were uniform. The triple-drug group (n = 166) underwent TACE using ethiodized oil with doxorubicin, cisplatin, and mitomycin-C with a microsphere embolic. The single-drug group (n = 147) underwent TACE using doxorubicin-eluting beads. Group characteristics were classified and analyzed, and survival was calculated using standard statistical methods. All patients were followed until death. Those undergoing orthotopic liver transplant (OLT) were also followed. RESULTS: There were no significant differences between the two groups in terms of demographics, Child-Pugh class, or Okuda stage. With patients undergoing OLT censored (n = 73), the mean (± standard error) survival in the triple-drug group was 23.49 ± 2.38 months, and the median survival was 16.00 ± 1.51 months. Mean survival in the single-drug bead group was 28.16 ± 2.75 months, and the median survival was 15.00 ± 1.50 months (p = 0.168). With patients undergoing OLT censored, the mean and median survival for the total cohort were 26.25 ± 1.97 and 15.00 ± 1.08 months, respectively. In the entire cohort that did not undergo OLT, patients with Child-Pugh class A disease survived significantly longer than did patients with Child-Pugh class B disease. Elevated α-fetoprotein levels were associated with shorter survival, and patients undergoing TACE with drug-eluting beads had shorter hospital stays. Although a greater percentage annual survival was observed in patients undergoing drug-eluting bead TACE who had Child-Pugh class A, Okuda stage I, and Barcelona Clinic Liver Cancer classes A and B disease starting at 36 months, this suggested survival advantage did not reach statistical significance. CONCLUSION: We found no significant survival difference in patients with unresectable HCC treated with triple-drug TACE compared with single-drug TACE using doxorubicin-eluting beads.

Left ventricular shape predicts different types of cardiovascular events in the general population.

OBJECTIVE: To investigate whether sphericity volume index (SVI), an indicator of left ventricular (LV) remodelling, predicts incident cardiovascular events (coronary heart disease, CHD; all cardiovascular disease, CVD; heart failure, HF; atrial fibrillation, AF) over 10 years of follow-up in a multiethnic population (Multi-Ethnic Study of Atherosclerosis). METHODS: 5004 participants free of known CVD had magnetic resonance imaging (MRI) in 2000-2002. Cine images were analysed to compute, [Formula: see text] equivalent to LV volume/volume of sphere with length of LV as the diameter. The highest (greatest sphericity) and lowest (lowest sphericity) quintiles of SVI were compared against the reference group (2-4 quintiles combined). Risk-factor adjusted hazard's ratio (HR) from Cox regression assessed the predictive performance of SVI at end-diastole (ED) and end-systole (ES) to predict incident outcomes over 10 years in retrospective interpretation of prospective data. RESULTS: At baseline, participants were aged 61±10 years; 52% men and 39%/13%/26%/22% Cauc/Chinese/Afr-Amer/Hispanic. Low sphericity was associated with higher Framingham CVD risk, greater coronary calcium score and higher N-terminal pro-brain natriuretic peptide (NT-proBNP); while increased sphericity was associated with higher NT-proBNP and lower ejection fraction. Low sphericity predicted incident CHD (HR: 1.48, 1.55-2.59 at ED) and CVD (HR: 1.82, 1.47-2.27 at ED). However, both low (HR: 1.81, 1.20-2.73 at ES) and high (HR: 2.21, 1.41-3.46 at ES) sphericity predicted incident HF. High sphericity also predicted AF. CONCLUSIONS: In a multiethnic population free of CVD at baseline, lowest sphericity was a predictor of incident CHD, CVD and HF over a 10-year follow-up period. Extreme sphericity was a strong predictor of incident HF and AF. SVI improved risk prediction models beyond established risk factors only for HF, but not for all CVD or CHD.

Natural History of Myocardial Function in an Adult Human Population: Serial Longitudinal Observations From MESA.

OBJECTIVES: The aim of this longitudinal study was to define the determinants of aging-related left ventricular (LV) remodeling and function in a large multiethnic population. BACKGROUND: The influence of risk factor exposure on myocardial remodeling and function in humans across adult life remains incompletely understood. MESA (Multi-Ethnic Study of Atherosclerosis) is a longitudinal population-based cohort of asymptomatic adults at baseline. METHODS: We examined 757 participants who were free of clinical cardiovascular disease and underwent tagged cardiac magnetic resonance both at baseline and at the 10-year follow-up as part of the MESA study. LV remodeling, circumferential shortening (CS), and torsion were assessed by tagged cardiac magnetic resonance. Multivariable linear regression was used to determine the association of changes in risk factors with changes in cardiac geometry and function. RESULTS: The mean age of participants was 63 ± 9 years at baseline; 50% were women. Overall, the LV mass-to-volume ratio increased by 10% over 10 years (p < 0.01). CS was unchanged (17.8% to 17.9%, p = 0.246), whereas torsion increased by 13% (3.8°/cm to 4.3°/cm, p < 0.001). Increased systolic blood pressure was associated with reduced CS (-0.02%/mm Hg, p < 0.01). Participants who remained on antihypertensive therapy during the whole study had a greater decrease in LV mass-to-volume ratio (-0.045 vs. no medication, p < 0.05) with a greater increase in CS (0.78% vs. no medication, p < 0.01). Moreover, greater LV mass at baseline was significantly associated with reduced CS (-0.02%/g, p < 0.01) and torsion (-0.02°/cm/g, p < 0.01) independently of risk factors. CONCLUSIONS: Longitudinal observation demonstrates that LV mass and worsening risk factors are fundamental determinants of reduced regional myocardial shortening over 10 years. Increased torsion of the myocardial wall is seen with progressive concentric remodeling and may explain why systolic function is maintained with aging.

Ten-year longitudinal change in aortic stiffness assessed by cardiac MRI in the second half of the human lifespan: the multi-ethnic study of atherosclerosis.

AIMS: Longitudinal determinants of aortic stiffness (AS) measured by magnetic resonance imaging (MRI) have not been assessed in a large community-based population. Our aim was to examine the determinants of change in thoracic AS over 10 years of follow-up in a multi-ethnic population of individuals 45 years of age and older measured by MRI. METHODS AND RESULTS: We studied 1160 participants (mean age = 60 ± 9 years at baseline, 45% male) with aortic MRI at both the MESA Year 0 and Year 10 examinations. Ascending and descending aorta distensibility (AAD/DAD) and aortic arch pulse-wave velocity (PWV) were measured using MRI. Determinants of the change in AS parameters over 10 years were assessed using linear regression adjusted for baseline values, demographic variables, baseline risk factors and change in risk factors, and chronic risk exposure. AAD and DAD decreased slightly (5% decrease in median for AAD: 1.33-1.26 mmHg(-1) · 10(-3), P = 0.008; 5% decrease in median for DAD: 1.73-1.64 mmHg(-1) · 10(-3), P < 0.001), and PWV increased over 10 years (18% increase in median: 6.8-8.0 m/s P < 0.001). Baseline age was related to a reduction in AAD and DAD and an increase in PWV throughout the follow-up period. Baseline and change in mean blood pressure and continued smoking were associated with a reduction in AAD and an increase in PWV. Furthermore, baseline heart rate was also related to a reduction in AAD and DAD. Blood pressure normalization was related to less aortic stiffening throughout the follow-up period. CONCLUSIONS: In our longitudinal, community-based cohort study of adult individuals aged 45 years or greater, greater mean blood pressure and a history of smoking history were associated with increased aortic stiffening over 10 years as assessed by MRI.

Reduced long axis strain is associated with heart failure and cardiovascular events in the multi-ethnic study of Atherosclerosis.

PURPOSE: To propose long axis strain (LAS), a novel index of global left ventricle (LV) function, as a sensitive and powerful predictor of hard cardiovascular events and heart failure in the Multi-Ethnic Study of Atherosclerosis (MESA). MATERIALS AND METHODS: Strain is an index of relative myocardial deformation, and enables normalization for differences in heart size. Measurement of strain conventionally requires dedicated software and protocols for image acquisition. LAS, however, can be analyzed using a caliper tool from conventional LV long axis magnetic resonance imaging (MRI) cine loops, reflecting the average myocardial contraction in the longitudinal direction. In all, 1651 participants (53% men) of the MESA study, without a history of myocardial infarction or heart failure, were assessed using conventional cine MR images. LV lengths were assessed at end-diastole (EDL ) and end-systole (ESL ), and LAS was calculated as 100*(EDL -ESL )/EDL . Participants were followed for 6.8 ± 1.8 years for a composite endpoint of congestive heart failure or hard cardiovascular events, and the predictive ability of LAS was tested, unadjusted and adjusted for established cardiovascular risk factors. RESULTS: A total of 114 events were observed. Mean LAS was 11.7 ± 2.5% and 10.0 ± 2.7% in participants without and with events, respectively (P < 0.001). Increased LAS reduced the hazard ratio to 0.75 for univariate, and 0.88 for multivariate assessments, respectively (both P < 0.001). CONCLUSION: Assessment of long axis LV deformation by LAS is feasible and reproducible. Moreover, LAS predicts hard cardiovascular events and congestive heart failure in a multi-ethnic population without overt cardiovascular disease at inclusion. J. Magn. Reson. Imaging 2016;44:178-185.

Adverse Left Ventricular Remodeling and Age Assessed with Cardiac MR Imaging: The Multi-Ethnic Study of Atherosclerosis.

PURPOSE: To evaluate age-related left ventricular (LV) remodeling during longitudinal observation of a large cohort of asymptomatic individuals who were free of clinical cardiovascular disease at baseline. MATERIALS AND METHODS: The applicable institutional review boards approved this study, and all participants gave informed consent. Cardiac magnetic resonance (MR) imaging was used to identify longitudinal changes in LV structure and function in 2935 participants who underwent baseline and follow-up cardiac MR imaging in the Multi-Ethnic Study of Atherosclerosis. Participants were free of clinical cardiovascular disease at baseline. Participants who experienced an incident coronary heart disease event were excluded. Data were analyzed with multivariable mixed-effects regression models in which the outcome was cardiac MR imaging measurement, and the covariates included follow-up time and cardiac risk factors. RESULTS: Participants were aged 54-94 years at follow-up, and 53% of the participants were women. Median time between baseline and follow-up cardiac MR imaging was 9.4 years. Over this period, LV mass increased in men and decreased slightly in women (8.0 and -1.6 g per decade, respectively; P < .001). In both men and women, LV end-diastolic volume decreased (-9.8 and -13.3 mL per decade, respectively; P < .001), stroke volume decreased (-8.8 and -8.6 mL per decade, respectively; P < .001), and mass-to-volume ratio increased (0.14 and 0.11 g/mL per decade, respectively; P < .001). Change in LV mass was positively associated with systolic blood pressure and body mass index and negatively associated with treated hypertension and high-density lipoprotein cholesterol level. In men, the longitudinal LV mass increase was in contrast to a cross-sectional pattern of LV mass decrease. CONCLUSION: As patients age, the LV responds differently in its mass and volume between men and women, although both men and women experience increased concentric LV remodeling with age. In men, the opposition of longitudinal and cross-sectional changes in LV mass highlights the importance of longitudinal study.

Pulmonary Microvascular Blood Flow in Mild Chronic Obstructive Pulmonary Disease and Emphysema. The MESA COPD Study.

RATIONALE: Smoking-related microvascular loss causes end-organ damage in the kidneys, heart, and brain. Basic research suggests a similar process in the lungs, but no large studies have assessed pulmonary microvascular blood flow (PMBF) in early chronic lung disease. OBJECTIVES: To investigate whether PMBF is reduced in mild as well as more severe chronic obstructive pulmonary disease (COPD) and emphysema. METHODS: PMBF was measured using gadolinium-enhanced magnetic resonance imaging (MRI) among smokers with COPD and control subjects age 50 to 79 years without clinical cardiovascular disease. COPD severity was defined by standard criteria. Emphysema on computed tomography (CT) was defined by the percentage of lung regions below -950 Hounsfield units (-950 HU) and by radiologists using a standard protocol. We adjusted for potential confounders, including smoking, oxygenation, and left ventricular cardiac output. MEASUREMENTS AND MAIN RESULTS: Among 144 participants, PMBF was reduced by 30% in mild COPD, by 29% in moderate COPD, and by 52% in severe COPD (all P < 0.01 vs. control subjects). PMBF was reduced with greater percentage emphysema-950HU and radiologist-defined emphysema, particularly panlobular and centrilobular emphysema (all P ≤ 0.01). Registration of MRI and CT images revealed that PMBF was reduced in mild COPD in both nonemphysematous and emphysematous lung regions. Associations for PMBF were independent of measures of small airways disease on CT and gas trapping largely because emphysema and small airways disease occurred in different smokers. CONCLUSIONS: PMBF was reduced in mild COPD, including in regions of lung without frank emphysema, and may represent a distinct pathological process from small airways disease. PMBF may provide an imaging biomarker for therapeutic strategies targeting the pulmonary microvasculature.

The association between cardiovascular risk and cardiovascular magnetic resonance measures of fibrosis: the Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND: Risk scores for cardiovascular disease (CVD) are in common use to integrate multiple cardiovascular risk factors in order to identify individuals at greatest risk for disease. The purpose of this study was to determine if individuals at greater cardiovascular risk have T1 mapping indices by cardiovascular magnetic resonance (CMR) indicative of greater myocardial fibrosis. METHODS: CVD risk scores for 1208 subjects (men, 50.8%) ages 55-94 years old were evaluated in the Multiethnic Study of Atherosclerosis (MESA) at six centers. T1 times were determined at 1.5Tesla before and after gadolinium administration (0.15 mmol/kg) using a modified Look-Locker pulse sequence. The relationship between CMR measures (native T1, 12 and 25 minute post-gadolinium T1, partition coefficient and extracellular volume fraction) and 14 established different cardiovascular risk scores were determined using regression analysis. Bootstrapping analysis with analysis of variance was used to compare different CMR measures. CVD risk scores were significantly different for men and women (p < 0.001). RESULTS: 25 minute post gadolinium T1 time showed more statistically significant associations with risk scores (10/14 scores, 71%) compared to other CMR indices (e.g. native T1 (7/14 scores, 50%) and partition coefficient (7/14, 50%) in men. Risk scores, particularly the new 2013 AHA/ASCVD risk score, did not correlate with any CMR fibrosis index. CONCLUSIONS: Men with greater CVD risk had greater CMR indices of myocardial fibrosis. T1 times at greater delay time (25 minutes) showed better agreement with commonly used risk score indices compared to ECV and native T1 time. CLINICAL TRIAL REGISTRATION: http://www.mesa-nhlbi.org/, NCT00005487.

Coil-Assisted Retrograde Transvenous Obliteration (CARTO) for the Treatment of Portal Hypertensive Variceal Bleeding: Preliminary Results.

OBJECTIVES: To describe the technical feasibility, safety, and clinical outcomes of coil-assisted retrograde transvenous obliteration (CARTO) in treating portal hypertensive non-esophageal variceal hemorrhage. METHODS: From October 2012 to December 2013, 20 patients who received CARTO for the treatment of portal hypertensive non-esophageal variceal bleeding were retrospectively evaluated. All 20 patients had at least 6-month follow-up. All patients had detachable coils placed to occlude the efferent shunt and retrograde gelfoam embolization to achieve complete thrombosis/obliteration of varices. Technical success, clinical success, rebleeding, and complications were evaluated at follow-up. RESULTS: A 100% technical success rate (defined as achieving complete occlusion of efferent shunt with complete thrombosis/obliteration of bleeding varices and/or stopping variceal bleeding) was demonstrated in all 20 patients. Clinical success rate (defined as no variceal rebleeding) was 100%. Follow-up computed tomography after CARTO demonstrated decrease in size with complete thrombosis and disappearance of the varices in all 20 patients. Thirteen out of the 20 had endoscopic confirmation of resolution of varices. Minor post-CARTO complications, including worsening of esophageal varices (not bleeding) and worsening of ascites/hydrothorax, were noted in 5 patients (25%). One patient passed away at 24 days after the CARTO due to systemic and portal venous thrombosis and multi-organ failure. Otherwise, no major complication was noted. No variceal rebleeding was noted in all 20 patients during mean follow-up of 384±154 days. CONCLUSIONS: CARTO appears to be a technically feasible and safe alternative to traditional balloon-occluded retrograde transvenous obliteration or transjugular intrahepatic portosystemic shunt, with excellent clinical outcomes in treating portal hypertensive non-esophageal variceal bleeding.