Comprehensive MRI analysis of early cardiac and vascular remodeling in middle-aged patients with abdominal obesity

Relationship Between Left Ventricular Ejection Fraction Variation and Systemic Vascular Resistance: A Prospective Cardiovascular Magnetic Resonance Study

Introduction: This cardiovascular magnetic resonance (CMR) study aims to determine whether changes in systemic vascular resistance (SVR), obtained from CMR flow sequences, might explain the significant long-term changes in left ventricular (LV) ejection fraction (EF) observed in subjects with no cardiac disease history. Methods: Cohort subjects without any known cardiac disease but with high rates of hypertension and obesity, underwent CMR with phase-contrast sequences both at baseline and at a median follow-up of 5.2 years. Longitudinal changes in EF were analyzed for any concomitant changes in blood pressure and vascular function, notably the indexed SVR given by the formula: mean brachial blood pressure / cardiac output x body surface area. Results: A total of 118 subjects (53 ± 12 years, 52% women) were included, 26% had hypertension, and 52% were obese. Eighteen (15%) had significant EF variations between baseline and follow-up (7 increased EF and 11 decreased EF). Longitudinal changes in EF were inversely related to concomitant changes in mean and diastolic blood pressures (p = 0.030 and p = 0.027, respectively) and much more significantly to SVR (p < 0.001). On average, these SVR changes were -8.08 ± 9.21 and +8.14 ± 8.28 mmHg.min.m².L^-1, respectively, in subjects with significant increases and decreases in EF, and 3.32 ± 7.53 mmHg.min.m².L^-1 in subjects with a stable EF (overall p < 0.001). Conclusions: Significant EF variations are not uncommon during the long-term CMR follow-up of populations with no evident health issues except for uncomplicated hypertension and obesity. However, most of these variations are linked to SVR changes and may therefore be unrelated to any intrinsic change in LV contractility. This underscores the benefits of specifically assessing LV afterload when EF is monitored in populations at risk of vascular dysfunction. Clinical Trial Registration: ClinicalTrials.gov, identifier: NCT01716819 and NCT02430805.

Arterial and Cardiac Remodeling Associated With Extra Weight Gain in an Isolated Abdominal Obesity Cohort

Introduction: This study aims to assess the changes in cardiovascular remodeling attributable to bodyweight gain in a middle-aged abdominal obesity cohort. A remodeling worsening might explain the increase in cardiovascular risk associated with a dynamic of weight gain. Methods: Seventy-five middle-aged subjects (56 ± 5 years, 38 women) with abdominal obesity and no known cardiovascular disease underwent MRI-based examinations at baseline and at a 6.1 ± 1.2-year follow-up to monitor cardiovascular remodeling and hemodynamic variables, most notably the effective arterial elastance (Ea). Ea is a proxy of the arterial load that must be overcome during left ventricular (LV) ejection, with increased EA resulting in concentric LV remodeling. Results: Sixteen obese subjects had significant weight gain (>7%) during follow-up (WG+), whereas the 59 other individuals did not (WG-). WG+ and WG- exhibited significant differences in the baseline to follow-up evolutions of several hemodynamic parameters, notably diastolic and mean blood pressures (for mean blood pressure, WG+: +9.3 ± 10.9 mmHg vs. WG-: +1.7 ± 11.8 mmHg, p = 0.022), heart rate (WG+: +0.6 ± 9.4 min^-1 vs. -8.9 ± 11.5 min^-1, p = 0.003), LV concentric remodeling index (WG: +0.08 ± 0.16 g.mL^-1 vs. WG-: -0.02 ± 0.13 g.mL^-1, p = 0.018) and Ea (WG+: +0.20 ± 0.28 mL mmHg^-1 vs. WG-: +0.01 ± 0.30 mL mmHg^-1, p = 0.021). The evolution of the LV concentric remodeling index and Ea were also strongly correlated in the overall obese population (p < 0.001, R² = 0.31). Conclusions: A weight gain dynamic is accompanied by increases in arterial load and load-related concentric LV remodeling in an isolated abdominal obesity cohort. This remodeling could have a significant impact on cardiovascular risk.

Effects of Exercise and Weight Loss on Proximal Aortic Stiffness in Older Adults With Obesity

BACKGROUND

Obesity may accelerate age-related increases in aortic stiffness. Although aerobic exercise training generally has favorable effects on aortic structure and function, exercise alone may not be sufficient to improve aortic stiffness in older adults with obesity. We determined the effects of aerobic exercise training with and without moderate- to high-caloric restriction (CR) on the structure and function of the proximal aorta in 160 older (65-79 years) men and women with obesity (body mass index=30-45 kg/m²).

METHODS

Participants were randomly assigned to 1 of 3 groups: aerobic exercise training only (treadmill 4 days/week for 30 minutes at 65% to 70% of heart rate reserve; n=56), aerobic exercise training plus moderate CR (n=55), or aerobic exercise training plus more intensive CR (n=49) for 20 weeks. Aortic pulse wave velocity, aortic distensibility, and other measures of aortic structure and function were assessed by cardiovascular magnetic resonance imaging. Pearson correlation coefficients were examined to assess associations between changes in proximal aortic stiffness and changes in fitness, fatness, and other potential confounders.

RESULTS

Weight loss in the aerobic exercise training plus moderate CR (-8.0 kg [95% CI, -9.17 to -6.87]) and aerobic exercise training plus more intensive CR (-8.98 kg [95% CI, -10.23 to -7.73) groups was significantly greater compared with the aerobic exercise training-only group (-1.66 kg [95% CI, -2.94 to -0.38]; P<0.017 for both). There were significant treatment effects for descending aorta distensibility (P=0.008) and strain (P=0.004) and aortic arch pulse wave velocity (P=0.01) with the aerobic exercise training plus moderate CR group having a 21% increase in distensibility (P=0.016) and an 8% decrease in pulse wave velocity (P=0.058). None of the aortic stiffness measures changed significantly in the aerobic exercise training-only or aerobic exercise training plus more intensive CR groups, and there were no significant changes in any other measure of aortic structure or function in these groups. Overall, increases in aortic distensibility were correlated with improvements in body weight and body fat distribution, but these associations were not statistically significant after adjustment for multiple comparisons.

CONCLUSIONS

In older adults with obesity, combining aerobic exercise with moderate CR leads to greater improvements in proximal aortic stiffness than exercise alone. Registration: URL: https://clinicaltrials.gov; Unique identifier: NCT01048736.

Metabolic syndrome and myocardium steatosis in subclinical type 2 diabetes mellitus: a 1H-magnetic resonance spectroscopy study

BACKGROUND

Metabolic syndrome (MetS) is a cluster of metabolic abnormalities that collectively cause an increased risk of type 2 diabetes mellitus (T2DM) and nonatherosclerotic cardiovascular disease. This study aimed to evaluate the role of myocardial steatosis in T2DM patients with or without MetS, as well as the relationship between subclinical left ventricular (LV) myocardial dysfunction and myocardial steatosis.

METHODS AND MATERIALS

We recruited 53 T2DM patients and 20 healthy controls underwent cardiac magnetic resonance examination. All T2DM patients were subdivide into two group: MetS group and non-MetS. LV deformation, perfusion parameters and myocardial triglyceride (TG) content were measured and compared among these three groups. Pearson's and Spearman analysis were performed to investigate the correlation between LV cardiac parameters and myocardial steatosis. The receiver operating characteristic curve (ROC) was performed to illustrate the relationship between myocardial steatosis and LV subclinical myocardial dysfunction.

RESULTS

An increase in myocardial TG content was found in the MetS group compared with that in the other groups (MetS vs. non-MetS: 1.54 ± 0.63% vs. 1.16 ± 0.45%; MetS vs. normal: 1.54 ± 0.63% vs. 0.61 ± 0.22%; all p < 0.001). Furthermore, reduced LV deformation [reduced longitudinal and radial peak strain (PS); all p < 0.017] and microvascular dysfunction [increased time to maximum signal intensity (TTM) and reduced Upslope; all p < 0.017)] was found in the MetS group. Myocardial TG content was positively associated with MetS (r = 0.314, p < 0.001), and it was independently associated with TTM (β = 0.441, p < 0.001) and LV longitudinal PS (β = 0.323, p = 0.021). ROC analysis exhibited that myocardial TG content might predict the risk of decreased LV longitudinal myocardial deformation (AUC = 0.74) and perfusion function (AUC = 0.71).

CONCLUSION

Myocardial TG content increased in T2DM patients with concurrent MetS. Myocardial steatosis was positively associated with decreased myocardial deformation and perfusion dysfunction, which may be an indicator for predicting diabetic cardiomyopathy.

Plasma Galectin-3 predicts deleterious vascular dysfunction affecting post-myocardial infarction patients: An explanatory study

OBJECTIVES

In a previous analysis of a post-myocardial infarction (MI) cohort, abnormally high systemic vascular resistances (SVR) were shown to be frequently revealed by MRI during the healing period, independently of MI severity, giving evidence of vascular dysfunction and limiting further recovery of cardiac function. The present ancillary and exploratory analysis of the same cohort was aimed at characterizing those patients suffering from high SVR remotely from MI with a large a panel of cardiovascular MRI parameters and blood biomarkers.

METHODS

MRI and blood sampling were performed 2-4 days after a reperfused MI and 6 months thereafter in 121 patients. SVR were monitored with a phase-contrast MRI sequence and patients with abnormally high SVR at 6-months were characterized through MRI parameters and blood biomarkers, including Galectin-3, an indicator of cardiovascular inflammation and fibrosis after MI. SVR were normal at 6-months in 90 patients (SVR-) and abnormally high in 31 among whom 21 already had high SVR at the acute phase (SVR++) while 10 did not (SVR+).

RESULTS

When compared with SVR-, both SVR+ and SVR++ exhibited lower recovery in cardiac function from baseline to 6-months, while baseline levels of Galectin-3 were significantly different in both SVR+ (median: 14.4 (interquartile range: 12.3-16.7) ng.mL-1) and SVR++ (13.0 (11.7-19.4) ng.mL-1) compared to SVR- (11.7 (9.8-13.5) ng.mL-1, both p < 0.05). Plasma Galectin-3 was an independent baseline predictor of high SVR at 6-months (p = 0.002), together with the baseline levels of SVR and left ventricular end-diastolic volume, whereas indices of MI severity and left ventricular function were not. In conclusion, plasma Galectin-3 predicts a deleterious vascular dysfunction affecting post-MI patients, an observation that could lead to consider new therapeutic targets if confirmed through dedicated prospective studies.

Correlation between left ventricular myocardial strain and left ventricular geometry in healthy adults: a cardiovascular magnetic resonance-feature tracking study

This study was aimed to investigate the correlation between left ventricular (LV) myocardial strain and LV geometry in healthy adults using cardiovascular magnetic resonance-feature tracking (CMR-FT). 124 gender-matched healthy adults who underwent healthy checkup using CMR cine imaging were retrospectively analyzed. Peak global radial, circumferential, longitudinal strain (GRS, GCS and GLS) for left ventricle were measured. LV geometry was assessed by the ratio of LV mass (LVM) and end-diastolic volume (EDV). GRS, GCS and GLS were 34.18 ± 6.71%, - 22.17 ± 2.28%, - 14.76 ± 2.39% for men, and 33.40 ± 6.95%, - 22.49 ± 2.27%, - 15.72 ± 2.36% for women. Multiple linear regression showed that LVM/EDV was associated with decreased GLS (β = - 0.297, p = 0.005), but was not significantly associated with GRS and GCS (both p > 0.05). There was an increase in the magnitude of GRS, GCS and GLS with advancing age (β = 0.254, β = 0.466 and β = 0.313, all p < 0.05). Greater BMI was associated with decreased GRS, GCS and GLS (β = - 0.232, β = - 0. 249 and β = - 0.279, all p < 0.05). In conclusion, compared with GRS and GCS, GLS is more sensitive to assess LV concentric remodeling in healthy adults. GRS, GCS and GLS are all independently positively associated with age and negatively associated with BMI. Sex-based LV strain reference values for healthy Chinese adults are established.

Cardiac remodeling following reperfused acute myocardial infarction is linked to the concomitant evolution of vascular function as assessed by cardiovascular magnetic resonance

BACKGROUND

Left ventricular (LV) remodeling following acute myocardial infarction (MI) is difficult to predict at an individual level although a possible interfering role of vascular function has yet to be considered to date. This study aimed to determine the extent to which this LV remodeling is influenced by the concomitant evolution of vascular function and LV loading conditions, as assessed by phase-contrast Cardiovascular Magnetic Resonance (CMR) of the ascending aorta.

METHODS

CMR was performed in 121 patients, 2-4 days after reperfusion of a first ST-segment elevation myocardial infarction and 6 months thereafter. LV remodeling was: (i) assessed by the 6-month increase in end-diastolic volume (EDV) and/or ejection fraction (EF) and (ii) correlated with the indexed aortic stroke volume (mL.m-2), determined by a CMR phase-contrast sequence, along with derived functional vascular parameters (total peripheral vascular resistance (TPVR), total arterial compliance index, effective arterial elastance).

RESULTS

At 6 months, most patients were under angiotensin enzyme converting inhibitors (86%) and beta-blockers (84%) and, on average, all functional vascular parameters were improved whereas blood pressure levels were not. An increase in EDV only (EDV+/EF-) was documented in 17% of patients at 6 months, in EF only (EDV-/EF+) in 31%, in both EDV and EF (EDV+/EF+) in 12% and neither EDV nor EF (EDV-/EF-) in 40%. The increase in EF was mainly and independently linked to a concomitant decline in TPVR (6-month change in mmHg.min.m2.L-1, EDV-/EF-: +1 ± 8, EDV+/EF-: +3 ± 9, EDV-/EF+: -7 ± 6, EDV+/EF+: -15 ± 20, p < 0.001) while the absence of any EF improvement was associated with high persisting rates of abnormally high TPVR at 6 months (EDV-/EF-: 31%, EDV+/EF-: 38%, EDV-/EF+: 5%, EDV+/EF+: 13%, p = 0.007). By contrast, the 6-month increase in EDV was mainly dependent on cardiac as opposed to vascular parameters and particularly on the presence of microvascular obstruction at baseline (EDV-/EF-: 37%, EDV+/EF-: 76%, EDV-/EF+: 38%, EDV+/EF+: 73%, p = 0.003).

CONCLUSION

LV remodeling following reperfused MI is strongly influenced by the variable decrease in systemic vascular resistance under standard care vasodilating medication. The CMR monitoring of vascular resistance may help to tailor these medications for improving vascular resistance and consequently, LV ejection fraction.

TRIAL REGISTRATION

NCT01109225 on ClinicalTrials.gov site (April, 2010).

Aortic compliance variation in long male distance triathletes: A new insight into the athlete's artery?

OBJECTIVES

To assess cardiac and vascular adaptations in long-distance male triathletes and the influence of an increased training volume on these parameters.

DESIGN

Case-control study using long-distance male triathletes (Tri) (n=12) and an age-matched cohort of sedentary volunteers (Ctrl).

METHODS

All participants gave an informed consent and underwent a Cardiovascular Magnetic Resonance imaging (CMR) exam to measure left and right ventricle functional parameters, and aortic parameters (surface, strain, compliance, pulse wave velocity). This exam was repeated in the triathletes' group after an increased training volume of at least 2h/week for six weeks.

RESULTS

Compared to control volunteers, triathletes presented at baseline a typical pattern of athlete's heart (higher end-diastolic, end-systolic and stroke volumes index, p≤0.009, and lower cardiac rate, p=0.015) but similar vascular characteristics except a trend towards an enlarged ascending aorta (surface 942±106 vs 812±127mm², p=0.058). Between the two visits, the triathletes increased their weekly training time from 9.67±2.43 (Tri1) to 12.15±3.01h (Tri2): no modifications were found regarding cardiac parameters, but compliance and distensibility of the ascending aorta increased, from 2.60 to 3.34mm²/mmHg (p=0.028) and from 3.36 to 4.40×10^-3mmHg^-1 (p=0.048) respectively.

CONCLUSIONS

Using CMR, we showed that vascular characteristics of the ascending aorta may vary along the sport season in endurance athletes. This remodelling could be considered as a physiological adaptation, but could eventually lead to an adverse vascular remodelling.

Influence of Thoracic Aortic Inflammation and Calcifications on Arterial Stiffness and Cardiac Function in Older Subjects

BACKGROUND

Vascular aging is accompanied by gradual remodeling affecting both arterial and cardiac structure and mechanical properties. Hypertension is suggested to exert pro-inflammatory actions enhancing arterial stiffness.

OBJECTIVE

To determine the influence of thoracic aortic inflammation and calcifications on arterial stiffness and cardiac function in hypertensive and normotensive older subjects.

DESIGN

A prospective study.

SETTING

An acute geriatrics ward of the University Hospital of Nancy in France.

SUBJECTS

Thirty individuals ≥ 65 years were examined, including 15 hypertensive subjects and 15 controls well-matched for age and sex.

MEASUREMENTS

Applanation tonometry was used to measure aortic pulse wave velocity (AoPWV) and carotid/brachial pulse pressure amplification (PPA). Left ventricular parameters were measured with magnetic resonance imaging. Local thoracic aortic inflammation and calcification were measured by 18 F-fluorodeoxyglucose positron emission tomography/computed tomography imaging. Biomarkers of low-grade inflammation were also quantified.

RESULTS

AoPWV was higher in elderly hypertensive subjects comparatively to normotensive controls (15.5±5.3 vs. 11.9±2.5, p=0.046), and hypertensives had a higher calcification volume. In the overall population, calcifications of the thoracic descending aorta and inflammation of the ascending aorta accounted for respectively 18.1% (p=0.01) and 9.6% (p=0.07) of AoPWV variation. Individuals with high levels of calcifications and/or inflammation had higher AoPWV (p=0.003). Inflammation had a negative effect on PPA explaining 13.8% of its variation (p<0.05).

CONCLUSION

This study highlights the importance of local ascending aortic inflammation as a potential major actor in the determination of PPA while calcifications and hypertension are more linked to AoPWV. Assessment of PPA in the very elderly could provide complementary information to improve diagnostic and therapeutic strategies targeting ascending aortic inflammation.

Central pulse pressure is a determinant of heart and brain remodeling in the elderly: a quantitative MRI and PET pilot study

OBJECTIVE

The sustained elevation of blood pressure (BP) and especially of central pulse pressure (cPP) leads to heart and brain damage. This pilot study was aimed to precise the relationships between peripheral and central BP levels, and the remodeling of heart and brain as objectively quantified by cardiac MRI and brain F-fluorodeoxyglucose (FDG)-PET imaging in the elderly.

METHODS

Twenty-eight apparently healthy elderly individuals (66-85 years old, 14 women) were prospectively recruited and allocated into two half groups, one with and one without hypertension, and all were referred for the quantitative determinations of peripheral and central BP using applanation tonometry, indexed left ventricular mass (per m of body surface area) using cardiac MRI, and brain metabolism with a voxel-based analysis of FDG-PET images adjusted for age and sex.

RESULTS

Indexed left ventricular mass, reflecting cardiac remodeling, was correlated with the overall pressure variables involving both peripheral and central levels of systolic and pulse pressure (all P ≤ 0.001). By contrast, brain metabolism was significantly correlated with only cPP (P < 0.02). A cPP of at least 50  mmHg was associated with both a lower metabolism in frontal areas (P = 0.005) and a higher indexed left ventricular mass (P = 0.03).

CONCLUSION

This pilot study suggests that, when quantified by MRI and PET imaging, left ventricular mass and brain metabolism of elderly individuals are related to the cPP and to the 50  mmHg threshold, corresponding to what has previously been documented for the risk of cardiovascular event.

Assessment of a Monte-Carlo simulation of SPECT recordings from a new-generation heart-centric semiconductor camera: from point sources to human images

Geant4 application for tomographic emission (GATE), a Monte-Carlo simulation platform, has previously been used for optimizing tomoscintigraphic images recorded with scintillation Anger cameras but not with the new-generation heart-centric cadmium-zinc-telluride (CZT) cameras. Using the GATE platform, this study aimed at simulating the SPECT recordings from one of these new CZT cameras and to assess this simulation by direct comparison between simulated and actual recorded data, ranging from point sources to human images. Geometry and movement of detectors, as well as their respective energy responses, were modeled for the CZT 'D.SPECT' camera in the GATE platform. Both simulated and actual recorded data were obtained from: (1) point and linear sources of (99m)Tc for compared assessments of detection sensitivity and spatial resolution, (2) a cardiac insert filled with a (99m)Tc solution for compared assessments of contrast-to-noise ratio and sharpness of myocardial borders and (3) in a patient with myocardial infarction using segmented cardiac magnetic resonance imaging images. Most of the data from the simulated images exhibited high concordance with the results of actual images with relative differences of only: (1) 0.5% for detection sensitivity, (2) 6.7% for spatial resolution, (3) 2.6% for contrast-to-noise ratio and 5.0% for sharpness index on the cardiac insert placed in a diffusing environment. There was also good concordance between actual and simulated gated-SPECT patient images for the delineation of the myocardial infarction area, although the quality of the simulated images was clearly superior with increases around 50% for both contrast-to-noise ratio and sharpness index. SPECT recordings from a new heart-centric CZT camera can be simulated with the GATE software with high concordance relative to the actual physical properties of this camera. These simulations may be conducted up to the stage of human SPECT-images even if further refinement is needed in this setting.

Cardiovascular outcome associations among cardiovascular magnetic resonance measures of arterial stiffness: the Dallas heart study

BACKGROUND

Cardiovascular magnetic resonance (CMR) has been validated for the noninvasive assessment of total arterial compliance and aortic stiffness, but their associations with cardiovascular outcomes is unknown. The purpose of this study was to evaluate associations of CMR measures of total arterial compliance and two CMR measures of aortic stiffness with respect to future cardiovascular events.

METHODS

The study consisted of 2122 Dallas Heart Study participants without cardiovascular disease who underwent CMR at 1.5 Tesla. Aortic stiffness was measured by CMR-derived ascending aortic distensibility and aortic arch pulse wave velocity. Total arterial compliance was calculated by dividing left ventricular stroke volume by pulse pressure. Participants were monitored for cardiovascular death, non-fatal cardiac events, and non-fatal extra-cardiac vascular events over 7.8 ± 1.5 years. Cox proportional hazards regression was used to assess for associations between CMR measures and cardiovascular events.

RESULTS

Age, systolic blood pressure, and resting heart rate were independently associated with changes in ascending aortic distensibility, arch pulse wave velocity, and total arterial compliance (all p < .0001). A total of 153 participants (6.9%) experienced a cardiovascular event. After adjusting for traditional risk factors, total arterial compliance was modestly associated with increased risk for composite events (HR 1.07 per 1SD, p = 0.03) while the association between ascending aortic distensibility and composite events trended towards significance (HR 1.18 per 1SD, p = 0.08). Total arterial compliance and aortic distensibility were independently associated with nonfatal cardiac events (HR 1.11 per 1SD, p = 0.001 and HR 1.45 per 1SD, p = 0.0005, respectively), but not with cardiovascular death or nonfatal extra-cardiac vascular events. Arch pulse wave velocity was independently associated with nonfatal extra-cardiac vascular events (HR 1.18 per 1SD, p = 0.04) but not with cardiovascular death or nonfatal cardiac events.

CONCLUSIONS

In a multiethnic population free of cardiovascular disease, CMR measures of arterial stiffness are associated with future cardiovascular events. Total arterial compliance and aortic distensibility may be stronger predictors of nonfatal cardiac events, while pulse wave velocity may be a stronger predictor of nonfatal extra-cardiac vascular events.

Features of cardiac remodeling, associated with blood pressure and fibrosis biomarkers, are frequent in subjects with abdominal obesity

Incidence and prevalence of abdominal obesity (AO) are growing exponentially. Subjects with AO are at higher risk of developing heart failure. The purpose of the study was to investigate early changes in cardiac and arterial structure and function and extracellular matrix biomarkers in normotensive healthy subjects with AO. Subjects with AO and age- and sex-matched controls underwent echocardiography, MRI (cardiac remodeling index), carotid intima-media thickness, pulse wave velocity, and blood fibrosis biomarkers measurements. We enrolled 87 subjects with AO and 53 controls. Although normotensive, subjects with AO had higher systolic blood pressure (BP; 122±11 versus 116±11 mm Hg; P=0.003), left ventricular mass (94±24 versus 84±21 g; P=0.034), and cardiac remodeling index (0.67±0.16 versus 0.60±0.10 g/mL; P=0.026) but unchanged carotid intima-media thickness and pulse wave velocity. Diastolic dysfunction (E' <10 cm/s) could be detected in 38% of subjects with AO (4% in controls). Left ventricular remodeling, as assessed by cardiac remodeling index, was positively and independently associated with higher BP (systolic BP and mean arterial pressure but not diastolic BP) and AO. Higher BP, AO, and procollagen-III-N-terminal peptide (≥2.4 ng/mL) concentrations (odds ratio, 4.15 [1.42-12.2]; P=0.01) were positively associated with diastolic dysfunction. Early cardiac structural remodeling, fibrosis, and diastolic dysfunction were detectable in healthy subjects with AO. Higher BP, procollagen-III-N-terminal peptide, and AO were independently associated with early cardiac structural and functional changes. It is to be investigated whether in subjects with AO, an early BP reduction, even if normotensive, combined with weight loss may avoid adverse cardiac remodeling and protect against progression to heart failure.

Cardiac steatosis and left ventricular function in men with metabolic syndrome

BACKGROUND

Ectopic accumulation of fat accompanies visceral obesity with detrimental effects. Lipid oversupply to cardiomyocytes leads to cardiac steatosis, and in animal studies lipotoxicity has been associated with impaired left ventricular (LV) function. In humans, studies have yielded inconclusive results. The aim of the study was to evaluate the role of epicardial, pericardial and myocardial fat depots on LV structure and function in male subjects with metabolic syndrome (MetS).

METHODS

A study population of 37 men with MetS and 38 men without MetS underwent cardiovascular magnetic resonance and proton magnetic spectroscopy at 1.5 T to assess LV function, epicardial and pericardial fat area and myocardial triglyceride (TG) content.

RESULTS

All three fat deposits were greater in the MetS than in the control group (p <0.001). LV diastolic dysfunction was associated with MetS as measured by absolute (471 mL/s vs. 667 mL/s, p = 0.002) and normalized (3.37 s⁻¹ vs. 3.75 s⁻¹, p = 0.02) LV early diastolic peak filling rate and the ratio of early diastole (68% vs. 78%, p = 0.001). The amount of epicardial and pericardial fat correlated inversely with LV diastolic function. However, myocardial TG content was not independently associated with LV diastolic dysfunction.

CONCLUSIONS

In MetS, accumulation of epicardial and pericardial fat is linked to the severity of structural and functional alterations of the heart. The role of increased intramyocardial TG in MetS is more complex and merits further study.

New echocardiographic techniques in the evaluation of left ventricular function in obesity

OBJECTIVE

Obesity has reached global epidemic proportions and is associated with numerous comorbidities, including major cardiovascular (CV) diseases.

DESIGN AND METHODS

It has many adverse effects on hemodynamics and CV structure and function: it increases total blood volume and cardiac output, and the cardiac workload is greater. Typically, obese patients have a higher cardiac output but a lower level of total peripheral resistance at any given level of arterial pressure. Most of the increase in cardiac output in obesity is caused by stroke volume, although heart rate typically mildly increases also due to enhanced sympathetic activation.

RESULTS

Over the last few years, experimental investigations have unraveled some important pathogenetic mechanisms that may underlie a specific form of "obesity cardiomyopathy." Bariatric surgery represents an effective alternative to treat obesity when nonsurgical weight loss programs (diet + behavior modifications + regular exercise) have failed. A great numbers of questions are still open in the global comprehension of the pathophysiological interactions between obesity and heart.

CONCLUSION

Conventional two-dimensional Doppler echocardiography, integrated by relative new technological ultrasonic approaches, represents the reference technique to study and possibly clarify both the very complex hemodynamic changes induced by obesity and those relative to obesity treatment.