Association between Left Atrial Late Gadolinium Enhancement and Atrial Fibrillation: The Multi-Ethnic Study of Atherosclerosis (MESA).

Purpose: To determine the prevalence and correlates of left atrial (LA) late gadolinium enhancement (LGE) at cardiac MRI and its association with atrial fibrillation (AF) in a population-based sample from the Multi-Ethnic Study of Atherosclerosis (MESA). Materials and Methods: In this secondary post hoc analysis of the MESA cohort (ClinicalTrials.gov no. NCT00005487), participants without AF underwent LGE cardiac MRI at the fifth examination (2010-2012). LA LGE burden was quantified using the image intensity ratio technique on biplane long-axis two-dimensional (2D) LGE images without fat saturation. Survival analysis was performed with log-rank testing and Cox regression. Results: Of 1697 participants (mean age, 67 years ± 9 [SD]; 872 men), 1035 (61%) had LA LGE, and 75 (4.4%) developed AF during follow-up (median, 3.95 years). At univariable analysis, LA LGE was associated with age (ß = .010 [95% CI: .005, .015], P < .001), diastolic blood pressure (ß = .005 [95% CI: .001, .009], P = .02), HbA1c level (ß = .06 [95% CI: .02, .11], P = .009), heart failure (ß = .60 [95% CI: .11, 1.08], P = .02), LA volume (ß = .008 [95% CI: .004, .012], P < .001), and LA function (emptying fraction, LA global longitudinal strain, LA early diastolic peak longitudinal strain rate, and LA late diastolic peak strain rate; all P < .05). After adjusting for the variables in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) AF score, LA LGE independently helped predict incident AF (hazard ratio = 1.46 [95% CI: 1.13, 1.88], P = .003). The highest tertile (LGE > 2%) was twice as likely to develop AF. Conclusion: Although limited by the 2D LGE technique employed, LA LGE was associated with adverse atrial remodeling and helped predict AF in a multiethnic population-based sample.Clinical trial registration no. NCT00005487Keywords: MR Imaging, Cardiac, Epidemiology Supplemental material is available for this article. © RSNA, 2023.

Adipose tissue biomarkers and type 2 diabetes incidence in normoglycemic participants in the MESArthritis Ancillary Study: A cohort study.

BACKGROUND: Given the central role of skeletal muscles in glucose homeostasis, deposition of adipose depots beneath the fascia of muscles (versus subcutaneous adipose tissue [SAT]) may precede insulin resistance and type 2 diabetes (T2D) incidence. This study was aimed to investigate the associations between computed tomography (CT)-derived biomarkers for adipose tissue and T2D incidence in normoglycemic adults. METHODS AND FINDINGS: This study was a population-based multiethnic retrospective cohort of 1,744 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) with normoglycemia (baseline fasting plasma glucose [FPG] less than 100 mg/dL) from 6 United States of America communities. Participants were followed from April 2010 and January 2012 to December 2017, for a median of 7 years. The intermuscular adipose tissue (IMAT) and SAT areas were measured in baseline chest CT exams and were corrected by height squared (SAT and IMAT indices) using a predefined measurement protocol. T2D incidence, as the main outcome, was based on follow-up FPG, review of hospital records, or self-reported physician diagnoses. Participants' mean age was 69 ± 9 years at baseline, and 977 (56.0%) were women. Over a median of 7 years, 103 (5.9%) participants were diagnosed with T2D, and 147 (8.4%) participants died. The IMAT index (hazard ratio [HR]: 1.27 [95% confidence interval [CI]: 1.15-1.41] per 1-standard deviation [SD] increment) and the SAT index (HR: 1.43 [95% CI: 1.16-1.77] per 1-SD increment) at baseline were associated with T2D incidence over the follow-up. The associations of the IMAT and SAT indices with T2D incidence were attenuated after adjustment for body mass index (BMI) and waist circumference, with HRs of 1.23 (95% CI: 1.09-1.38) and 1.29 (95% CI: 0.96-1.74) per 1-SD increment, respectively. The limitations of this study include unmeasured residual confounders and one-time measurement of adipose tissue biomarkers. CONCLUSIONS: In this study, we observed an association between IMAT at baseline and T2D incidence over the follow-up. This study suggests the potential role of intermuscular adipose depots in the pathophysiology of T2D. TRIAL REGISTRATION: ClinicalTrials.gov NCT00005487.

Quantitative Analysis of Adipose Depots by Using Chest CT and Associations with All-Cause Mortality in Chronic Obstructive Pulmonary Disease: Longitudinal Analysis from MESArthritis Ancillary Study.

Background Obesity and sarcopenia are associated with mortality in chronic obstructive pulmonary disease (COPD). Routine chest CT examinations may allow assessment of obesity and sarcopenia by soft-tissue markers for predicting risks of mortality. Purpose To investigate associations between soft-tissue markers subcutaneous adipose tissue (SAT), intermuscular adipose tissue (IMAT), and pectoralis muscle (PM) index from chest CT with mortality in participants with COPD. Materials and Methods In this secondary analysis of a prospectively enrolled cohort from the Multi-Ethnic Study of Atherosclerosis, participants with available chest CT in 2010-2012 were included. CT examinations were analyzed to determine SAT, IMAT (within PM), and PM areas. The spirometry evaluations were used to establish COPD diagnosis. Mortality data were extracted from the National Death Index (April 2010 to December 2017). The correlations of the soft-tissue markers with fat mass index were studied. The associations of these markers and risks of mortality in participants with COPD were assessed by using Cox proportional-hazard models adjusted for confounders. Results Among 2994 participants who were included (mean age, 69 years ± 9 [standard deviation]; 1551 women), 265 had COPD (9%; mean age, 72 years ± 9; 162 men) and 49 participants with COPD (18%) died during follow-up. The SAT, IMAT, and PM areas had moderate-to-excellent reliabilities (intraclass correlation coefficient, 0.88-0.99). In the 2994 participants, the SAT (ρ = 0.80; 95% CI: 0.78, 0.81; P < .001) and IMAT indexes (ρ = 0.37; 95% CI: 0.34, 0.41; P < .001) were correlated with fat mass index. Those with COPD and higher SAT index had lower risks of mortality (hazard ratio, 0.2; 95% CI: 0.1, 0.4; P < .001, per doubling), whereas a higher IMAT index was associated with a higher risk of mortality (hazard ratio, 1.4; 95% CI: 1.0, 1.9; P = .04, per doubling). Conclusion Soft-tissue markers were reliably obtained by using chest CT performed for lung assessment. In participants with chronic obstructive pulmonary disease, a high intermuscular adipose tissue index was associated with a higher risk of mortality than was a high subcutaneous adipose tissue index. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Sverzellati and Cademartiri in this issue.

Anthracycline Therapy Is Associated With Cardiomyocyte Atrophy and Preclinical Manifestations of Heart Disease.

OBJECTIVES: The goal of this study was to demonstrate that cardiac magnetic resonance could reveal anthracycline-induced early tissue remodeling and its relation to cardiac dysfunction and left ventricular (LV) atrophy. BACKGROUND: Serum biomarkers of cardiac dysfunction, although elevated after chemotherapy, lack specificity for the mechanism of myocardial tissue alterations. METHODS: A total of 27 women with breast cancer (mean age 51.8 ± 8.9 years, mean body mass index 26.9 ± 3.6 kg/m2), underwent cardiac magnetic resonance before and up to 3 times after anthracycline therapy. Cardiac magnetic resonance variables were LV ejection fraction, normalized T2-weighted signal intensity for myocardial edema, extracellular volume (ECV), LV cardiomyocyte mass, intracellular water lifetime (τic; a marker of cardiomyocyte size), and late gadolinium enhancement. RESULTS: At baseline, patients had a relatively low (10-year) Framingham cardiovascular event risk (median 5%), normal LV ejection fractions (mean 69.4 ± 3.6%), and normal LV mass index (51.4 ± 8.0 g/m2), a mean ECV of 0.32 ± 0.038, mean τic of 169 ± 69 ms, and no late gadolinium enhancement. At 351 to 700 days after anthracycline therapy (240 mg/m2), mean LV ejection fraction had declined by 12% to 58 ± 6% (p < 0.001) and mean LV mass index by 19 g/m2 to 36 ± 6 g/m2 (p < 0.001), and mean ECV had increased by 0.037 to 0.36 ± 0.04 (p = 0.004), while mean τic had decreased by 62 ms to 119 ± 54 ms (p = 0.004). Myocardial edema peaked at about 146 to 231 days (p < 0.001). LV mass index was associated with τic (ß = 4.1 ± 1.5 g/m2 per 100-ms increase in τic, p = 0.007) but not with ECV. Cardiac troponin T (mean 4.6 ± 1.4 pg/ml at baseline) increased significantly after anthracycline treatment (p < 0.001). Total LV cardiomyocyte mass, estimated as: (1 - ECV) × LV mass, declined more rapidly after anthracycline therapy, with peak cardiac troponin T >10 pg/ml. There was no evidence for any significant interaction between 10-year cardiovascular event risk and the effect of anthracycline therapy. CONCLUSIONS: A decrease in LV mass after anthracycline therapy may result from cardiomyocyte atrophy, demonstrating that mechanisms other than interstitial fibrosis and edema can raise ECV. The loss of LV cardiomyocyte mass increased with the degree of cardiomyocyte injury, assessed by peak cardiac troponin T after anthracycline treatment. (Doxorubicin-Associated Cardiac Remodeling Followed by CMR in Breast Cancer Patients; NCT03000036).