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An observational study of the association among interatrial adiposity by computed tomography measure, insulin resistance, and left atrial electromechanical disturbances in heart failure

View Article: PubMed Central - PubMed

ABSTRACT

Excessive visceral adiposity, hypothesized to be a key mediator in metabolic derangements, has recently been shown to exert toxic effects on cardiac structure and function. Data regarding the mechanistic link between regional adiposity, left atrial (LA) electromechanical remodeling, and heart failure with preserved ejection fraction (HFpEF) have been lacking.

Various visceral adiposity measures, including pericardial fat (PCF), thoracic periaortic (TAT) fat, regional inter-atrial fat (IAF), and atrioventricular groove fat (AV Groove Fat), were assessed by multidetector computed tomography in 2 study cohorts (an annual health survey cohort and an outpatient cohort). We related such measures to cardiometabolic profiles in health survey cohort and LA electromechanical indices in our outpatient cohort, with Cox proportional hazards performed to examine the temporal trends of heart failure (HF).

In our annual health survey cohort (n = 362), all 4 adiposity measures were positively related to unfavorable anthropometrics and systemic inflammation (high-sensitivity C-reactive protein) (all P < 0.05). In addition, both greater IAF and AV Groove Fat were positively associated with higher fasting glucose, HbA1c levels, and insulin resistance (all P < 0.05). In the outpatient cohort, the HFpEF group demonstrated the greatest adiposity measures, with greater IAF (≥8.2 mm, hazard ratio: 4.11, 95% confidence interval: 1.50–11.32) associated with reduced LA strain (ß-coef: –0.28), higher LA stiffness (ß-coef: 0.23), and longer P wave duration (ß-coef: 0.23) in multivariate models (all P < 0.05), and further related to higher HF hospitalization during follow-up.

We therefore propose a possible pathophysiologic link among greater visceral adiposity, systemic inflammation, cardiometabolic risks, and HFpEF. Regional adiposity, especially IAF, was tightly linked to altered LA electromechanical properties and likely plays a key role in HF prognosis.

No MeSH data available.


Related in: MedlinePlus

(A, B) Measurements of total volume of peri-cardial fat tissue (PCF) and thoracic periaortic fat tissue (TAT). Orange color indicated PCF and TAT in axial, sagital, coronal views, and 3-dimensional reconstructions. (C) Thickness of PCF in interatrial septum (solid line) and left atrioventricular groove (dotted line) was measured in the horizontal long-axis view. (D) Left atrial (LA) deformation (LA strain, %) analysis by using 2-dimensional speckle-tracking technique and corresponding curves were displayed.
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Figure 1: (A, B) Measurements of total volume of peri-cardial fat tissue (PCF) and thoracic periaortic fat tissue (TAT). Orange color indicated PCF and TAT in axial, sagital, coronal views, and 3-dimensional reconstructions. (C) Thickness of PCF in interatrial septum (solid line) and left atrioventricular groove (dotted line) was measured in the horizontal long-axis view. (D) Left atrial (LA) deformation (LA strain, %) analysis by using 2-dimensional speckle-tracking technique and corresponding curves were displayed.

Mentions: Contrast injection (iopamiro 370 mg/mL, Bracco, Italy) was administered (60–85 mL) at an injection rate of 5 mL/s with a delay calculated during the timing bolus scan. Overlapping transaxial images were reconstructed using a medium sharp convolution kernel (B25f) with an image matrix of 512 × 512 pixels, slice thickness and increment of 0.75/0.4 mm using an ECG-gated half-scan algorithm. Image reconstruction was retrospectively gated to ECG. Reconstructed image data were transferred to a dedicated workstation (Aquarius 3D Workstation, TeraRecon, San Mateo, CA) for subsequent visceral adipose tissue, pericardial fat (PCF), and thoracic periaortic (TAT) analyses. The semiautomatic segmentation technique was developed for quantification of fat volumes. We traced the region of interest manually and defined fat tissue by using Hounsfield units (HU) as pixels with the attenuation of −190 to −30 HU, which corresponded to adipose tissue in contrast-enhanced cardiac CT scans.[17] PCF was defined as any adipose tissue volume (unit: mL) located within the pericardial sac (Fig. 1A). TAT tissue was defined as volume (unit: mL) of the adipose tissue surrounding the thoracic aorta, which extended 67.5 mm from the level of the bifurcation of pulmonary arteries as start point, with cranial-caudal coverage of the thoracic aorta to the diaphragm as its lower anatomical limit (Fig. 1B). For acquiring the thickness of regional epicardial adipose tissue (unit: mm), we further adjusted the imaging plane into horizontal long-axis plane for the measurements of inter-atrial fat (IAF) and atrioventricular (AV) groove fat (Fig. 1C). This approach has been validated previously.[18]


An observational study of the association among interatrial adiposity by computed tomography measure, insulin resistance, and left atrial electromechanical disturbances in heart failure
(A, B) Measurements of total volume of peri-cardial fat tissue (PCF) and thoracic periaortic fat tissue (TAT). Orange color indicated PCF and TAT in axial, sagital, coronal views, and 3-dimensional reconstructions. (C) Thickness of PCF in interatrial septum (solid line) and left atrioventricular groove (dotted line) was measured in the horizontal long-axis view. (D) Left atrial (LA) deformation (LA strain, %) analysis by using 2-dimensional speckle-tracking technique and corresponding curves were displayed.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4998482&req=5

Figure 1: (A, B) Measurements of total volume of peri-cardial fat tissue (PCF) and thoracic periaortic fat tissue (TAT). Orange color indicated PCF and TAT in axial, sagital, coronal views, and 3-dimensional reconstructions. (C) Thickness of PCF in interatrial septum (solid line) and left atrioventricular groove (dotted line) was measured in the horizontal long-axis view. (D) Left atrial (LA) deformation (LA strain, %) analysis by using 2-dimensional speckle-tracking technique and corresponding curves were displayed.
Mentions: Contrast injection (iopamiro 370 mg/mL, Bracco, Italy) was administered (60–85 mL) at an injection rate of 5 mL/s with a delay calculated during the timing bolus scan. Overlapping transaxial images were reconstructed using a medium sharp convolution kernel (B25f) with an image matrix of 512 × 512 pixels, slice thickness and increment of 0.75/0.4 mm using an ECG-gated half-scan algorithm. Image reconstruction was retrospectively gated to ECG. Reconstructed image data were transferred to a dedicated workstation (Aquarius 3D Workstation, TeraRecon, San Mateo, CA) for subsequent visceral adipose tissue, pericardial fat (PCF), and thoracic periaortic (TAT) analyses. The semiautomatic segmentation technique was developed for quantification of fat volumes. We traced the region of interest manually and defined fat tissue by using Hounsfield units (HU) as pixels with the attenuation of −190 to −30 HU, which corresponded to adipose tissue in contrast-enhanced cardiac CT scans.[17] PCF was defined as any adipose tissue volume (unit: mL) located within the pericardial sac (Fig. 1A). TAT tissue was defined as volume (unit: mL) of the adipose tissue surrounding the thoracic aorta, which extended 67.5 mm from the level of the bifurcation of pulmonary arteries as start point, with cranial-caudal coverage of the thoracic aorta to the diaphragm as its lower anatomical limit (Fig. 1B). For acquiring the thickness of regional epicardial adipose tissue (unit: mm), we further adjusted the imaging plane into horizontal long-axis plane for the measurements of inter-atrial fat (IAF) and atrioventricular (AV) groove fat (Fig. 1C). This approach has been validated previously.[18]

View Article: PubMed Central - PubMed

ABSTRACT

Excessive visceral adiposity, hypothesized to be a key mediator in metabolic derangements, has recently been shown to exert toxic effects on cardiac structure and function. Data regarding the mechanistic link between regional adiposity, left atrial (LA) electromechanical remodeling, and heart failure with preserved ejection fraction (HFpEF) have been lacking.

Various visceral adiposity measures, including pericardial fat (PCF), thoracic periaortic (TAT) fat, regional inter-atrial fat (IAF), and atrioventricular groove fat (AV Groove Fat), were assessed by multidetector computed tomography in 2 study cohorts (an annual health survey cohort and an outpatient cohort). We related such measures to cardiometabolic profiles in health survey cohort and LA electromechanical indices in our outpatient cohort, with Cox proportional hazards performed to examine the temporal trends of heart failure (HF).

In our annual health survey cohort (n = 362), all 4 adiposity measures were positively related to unfavorable anthropometrics and systemic inflammation (high-sensitivity C-reactive protein) (all P < 0.05). In addition, both greater IAF and AV Groove Fat were positively associated with higher fasting glucose, HbA1c levels, and insulin resistance (all P < 0.05). In the outpatient cohort, the HFpEF group demonstrated the greatest adiposity measures, with greater IAF (≥8.2 mm, hazard ratio: 4.11, 95% confidence interval: 1.50–11.32) associated with reduced LA strain (ß-coef: –0.28), higher LA stiffness (ß-coef: 0.23), and longer P wave duration (ß-coef: 0.23) in multivariate models (all P < 0.05), and further related to higher HF hospitalization during follow-up.

We therefore propose a possible pathophysiologic link among greater visceral adiposity, systemic inflammation, cardiometabolic risks, and HFpEF. Regional adiposity, especially IAF, was tightly linked to altered LA electromechanical properties and likely plays a key role in HF prognosis.

No MeSH data available.


Related in: MedlinePlus