Paolo Preziosi

Age-related different relationships between ectopic adipose tissues and measures of central obesity in sedentary subjects.

Accumulation of fat at ectopic sites has been gaining attention as pivotal contributor of insulin resistance, metabolic syndrome and related cardiovascular complications. Intermuscular adipose tissue (IMAT), located between skeletal muscle bundles and beneath muscle fascia, has been linked to physical inactivity, ageing and body mass index, but little is known about its relationship with the other AT compartments, in particular with increasing age. To address this issue, erector spinae IMAT, epicardial (EAT), intraabdominal (IAAT) and abdominal subcutaneous adipose tissue (SAT) were simultaneously measured by Magnetic Resonance Imaging (MRI) and related to waist circumference measurements and age in 32 sedentary subjects without cardiovascular disease (18 men; 14 women; mean age 48.5±14 years). Fasting glucose, triglycerides and HDL-cholesterol were also assessed. We observed that, after dividing individuals according to age (≤ or >50 years), IMAT and EAT depots were significantly more expanded in older subjects (63.2±8.3 years) than in the younger ones (38.4±5.2 years) (p<0.001). Overall, both IMAT and EAT showed stronger positive associations with increasing age (β = 0.63 and 0.67, respectively, p<0.001 for both) than with waist circumference (β = 0.55 and 0.49, respectively, p<0.01 for both) after adjusting for gender. In addition, the gender-adjusted associations of IMAT and EAT with waist circumference and IAAT were significant in individuals ≤50 years only (p<0.05 for all) and not in the older ones. In contrast, no age-related differences were seen in the relationships of IAAT and SAT with waist circumference. Finally, serum triglycerides levels turned out not to be independently related with ectopic IMAT and EAT. In conclusion, the expansion of IMAT and EAT in sedentary subjects is more strongly related to age than waist circumference, and a positive association of these ectopic depots with waist circumference and IAAT amount can be postulated in younger individuals only.

Cardiac magnetic resonance detection of left ventricular thrombus in acute myocardial infarction.

Introduction: Left ventricular thrombosis (LVT) is a possible complication of acute myocardial infarction. Aim of our study was to evaluate incidence and clinical characteristics of patients with LVT after ST elevation myocardial infarction (STEMI) using contrast- enhanced magnetic resonance (CMR).Methods and Results: In a prospective cohort of 36 consecutive patients with STEMI acutely reperfused with primary percutaneous coronary intervention, CMR was performed within one week. LVT was found in 7 patients (19%), and was located in left ventricle apex or adherent to antero-septum. Compared to the rest of population patients with LVT have lower ejection fraction (38 ± 7% versus 51 ± 6%, P = 0.009), larger left ventricle end systolic volume (95.8 ± 19 ml versus 68.9 ± 19 ml, P = 0.02), higher time to reperfusion (9.3 ± 7.2 versus 5 ± 3.6, P = 0.03) and left anterior descending artery was constantly involved (100% versus 41 %, P = 0.06). In 5 cases the LVT was also detected by echocardiography, however, in 2 cases it was missed. Conclusions: The incidence of LVT after STEMI is not negligible and was accurately detected by CMR. Localization of myocardial infarction, time to reperfusion, ejection fraction and left ventricle end systolic volume are the most important predictors of left ventricle thrombus formation.

Relationship between Regional Fat Distribution and Hypertrophic Cardiomyopathy Phenotype

Background Hypertrophic cardiomyopathy (HCM), the most common genetic heart disease, is characterized by heterogeneous phenotypic expression. Body mass index has been associated with LV mass and heart failure symptoms in HCM. The aim of our study was to investigate whether regional (trunk, appendicular, epicardial) fat distribution and extent could be related to hypertrophy severity and pattern in HCM. Methods Cardiovascular magnetic resonance was performed in 32 subjects with echocardiography-based diagnosis of HCM (22M/10F, 57.2±12.6 years) characterized by predominant hypertrophy at the interventricular septum (IVS). Regional fat distribution was assessed by dual-energy X-ray absorptiometry. Results Gender differences were detected in maximum IVS thickness (M: 18.3±3.8 mm vs. F: 14.3±4 mm, p = 0.012), right ventricle (RV) systolic function (M: 61.3±6.7%; F: 67.5±6.3%, p = 0.048), indexed RV end-diastolic (M: 64.8±16.3 ml/m2; F: 50.7±15.5 ml/m2, p = 0.04) and end-systolic volumes (M: 24.3±8.3 ml/m2; F: 16.7±7.4 ml/m2, p = 0.04). After adjusting for age and gender, maximum IVS thickness was associated with truncal fat (Tr-FAT) (β = 0.43, p = 0.02), but not with either appendicular or epicardial fat. Epicardial fat resulted independently associated with NT-proBNP levels (β = 0.63, p = 0.04). Late Gadolinium Enhancement-positive subjects displayed greater maximum IVS thickness (p = 0.02), LV mass index (p = 0.015) and NT-proBNP levels (p = 0.04), but no associations with fat amount or distribution were observed. Conclusion Truncal, but not appendicular or epicardial fat amount, seems to be related with maximum IVS thickness, the hallmark feature in our cohort of HCM patients. Further prospective researches are needed to assess a potential causative effect of central adiposity on HCM phenotype.

Prognostic CMR parameters for heart failure and arrhythmias in large cohort of well treated thalssemia major patients

Background Cardiac complications are the main cause of death in thalassemia major (TM) patients. Cardiovascular Magnetic Resonance (CMR) plays a key role in their management, assessing myocardial iron overload (MIO), biventricular function, atrial dimensions, and myocardial fibrosis. We evaluated the predictive value of CMR parameters for heart failure and arrhythmias. Methods We followed prospectively 487 TM patients free of a cardiac complications at the first CMR. All prognostic variables associated with the outcome at the univariate Cox model were placed in the multivariate model and were ruled out if they did not significantly improve the adjustment. Results At baseline the mean age was 29.5 ± 9.0 years and 222 patients were males. The mean follow-up time was 58 ± 18 months. After the first CMR only the 37.8% of the patients did not change the chelation regimen or the frequency/dosage. We recorded 19 episodes of heart failure. Male sex, heart iron, ventricular dysfunction, ventricular dilation, atrial dilation, and myocardial fibrosis were significant univariate prognosticators. In the multivariate analysis the independent predictive factors were an homogeneous pattern of MIO (compared to no MIO) (HR = 5.81, 95%CI = 1.42-23.74, P = 0.014), myocardial fibrosis (HR = 4.93, 95%CI = 1.71-14.71, P = 0.003) and ventricular dysfunction (HR = 3.45, 95%CI = 1.19-9.98, P = 0.022). Figure 1 shows the Kaplan-Meier survival

Prospective changes of cardiac iron and function by MR in pediatric thalassemia major patients treated with different chelators or not chelated

Background There are no prospective studies comparing the effectiveness of the three iron chelators commercially available in preventing or decreasing iron overload in the heart in pediatric thalassemia major (TM) patients. Our aim was to evaluate the changes in cardiac iron and function by quantitative magnetic resonance imaging (MRI) over a follow-up (FU) of 18 months in pediatric TM patients treated with one of the 3 available iron chelators in monotherapy or non-chelated. Methods Among the first 1611 TM patients enrolled in the MIOT (Myocardial Iron Overload in Thalassemia) network, we considered pediatric patients who had maintained the same chelation regimen between the two MRI scans. Myocardial iron overload (MIO) was quantified by a multislice multiecho T2* sequence. Biventricular function parameters were evaluated by cine images. Due to the low sample size, no inter-treatment comparisons were performed.

Incremental value of cardiac magnetic resonance in the characterization of patients referred for left ventricular non compaction evaluation

Left ventricular non compaction (LVNC) is a rare cardiomyopathy due to a disorder of myocardial morphogenesis as the result of interruption during embryogenesis of the normal myocardium compaction. However, limited information is available regarding the actual impact of cardiovascular magnetic resonance (CMR) findings in reaching a diagnosis of LVNC in a population of patients(pt) referred to a CMR laboratory.