Early insulin resistance in normoglycemic low-risk individuals is associated with subclinical atherosclerosis

BACKGROUND

Elevated glycated hemoglobin (HbA1c) is associated with a higher burden of subclinical atherosclerosis (SA). However, the association with SA of earlier insulin resistance markers is poorly understood. The study assessed the association between the homeostatic model assessment of insulin resistance index (HOMA-IR) and SA in addition to the effect of cardiovascular risk factors (CVRFs) in individuals with normal HbA1c.

METHODS

A cohort of 3,741 middle-aged individuals from the Progression of Early Subclinical Atherosclerosis (PESA) study with basal HbA1c < 6.0% (< 42 mmol/mol) and no known CV disease underwent extensive imaging (multiterritorial vascular ultrasound and coronary artery calcium score, CACS) to assess the presence, burden, and extent of SA.

RESULTS

Individuals with higher HOMA-IR values had higher rates of CVRFs. HOMA-IR showed a direct association with the multiterritorial extent of SA and CACS (p < 0.001) and with global plaque volume measured by 3-dimensional vascular ultrasound (p < 0.001). After adjusting for key CVRFs and HbA1c, HOMA-IR values ≥ 3 were associated with both the multiterritorial extent of SA (odds ratio 1.41; 95%CI: 1.01 to 1.95, p = 0.041) and CACS > 0 (odds ratio 1.74; 95%CI: 1.20 to 2.54, p = 0.004), as compared with the HOMA-IR < 2 (the reference HOMA-IR category). In a stratified analysis, this association remained significant in individuals with a low-to-moderate SCORE2 risk estimate (75.6% of the cohort) but not in high-risk individuals.

CONCLUSIONS

The use of HOMA-IR identified low-risk individuals with a higher burden of SA, after adjusting for the effects of key traditional CVRFs and HbA1c. HOMA-IR is a simple measure that could facilitate earlier implementation of primary CV prevention strategies in clinical practice.

Cardiac magnetic resonance imaging derived reference values for ventricular anatomy and function and myocardial tissue characterization in adolescents: the EnIGMA study

Introduction

Cardiac magnetic resonance (CMR) imaging is a precise tool for the assessment of cardiac anatomy and function. However, studies providing reference values for CMR parameters, including myocardial tissue properties, in healthy adolescents are scarce.

Purpose

To provide CMR derived reference values for biventricular mass, volumes and function measured by cine steady-state free-precession (SSFP) sequences and myocardial tissue relaxation properties as measured by native T1- and T2-mapping sequences in healthy adolescents.

Methods

A comprehensive non-contrast CMR study was performed in healthy adolescents aged 15 to 18 years enrolled in the “Early ImaginG Markers of unhealthy lifestyles in Adolescents” (EnIGMA) project using a 3-Tesla CMR scanner between March 2021 and October 2021. The imaging protocol included a cine SSFP to provide high-quality images for chamber size and function analysis, and a T2-GraSE mapping and native T1-mapping sequences (MOLLI Scheme 5 (3) 3) to provide precise myocardial relaxation time properties. Images were analyzed by experienced observers using the Cardiac Analysis tool available at IntelliSpace Portal following a standard protocol. In cine SSFP sequences, right and left ventricles were manually contoured for end-diastolic and end-systolic phases in the short-axis orientation, respectively (Figure 1A, B). Native T1 and T2 maps were analyzed in a mid-ventricular short axis slice and summarized values per individual were determined (Figure 1C, D). Student's t-tests were used for between-gender comparisons.

Results

CMR scans were performed in 123 adolescents (63 girls, 51.2%) with a mean age of 16.0 years (standard deviation (SD)=0.5), mean body mass index of 21.4 (SD=3.2) kg/m2, mean body surface area of 1.69 (SD=0.16) m2, and mean heart rate during CMR acquisitions of 69 (SD=11) beats/minute. Reference percentiles (P) 3, 10, 25, 50, 75, 90 and 97 for the different parameters analyzed by gender are provided in Figure 2. Mean left and right ventricular end-diastolic indexed volumes were higher in boys than in girls (91.5 vs 78.1 ml/m2, p&lt;0.01; and 101.1 vs 84.2 ml/m2, p&lt;0.01), as well as the indexed cardiac mass (48.4 vs 36.4 g/m2, p&lt;0.01). Left ventricular ejection fraction (LVEF) was similar in boys and girls (62.0 vs. 62.9%, p=0.23), whereas right ventricular ejection fraction was slightly lower in boys than in girls (55.3 vs. 57.1%, p=0.03). Mean myocardial native T1 relaxation time was 1253 (SD=28) ms in girls and 1215 (SD=23) ms in boys (p&lt;0.01), whereas mean myocardial T2 relaxation time was 44.1 (SD=2.3) ms and 44.4 (SD=2.0) ms in girls and boys, respectively (p=0.46).

Conclusion

This study provided CMR derived reference values for biventricular anatomy, function, and myocardial tissue properties, in healthy adolescents aged 15 to 18 years. This information may be useful for the differential diagnosis of cardiac diseases, such as cardiomyopathies and myocarditis, in adolescent population.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Instituto de Salud Carlos III (ISCIII)-Fondo de Investigaciόn SanitariaEuropean Regional Development Fund/European Social Fund (“A way to make Europe”/“Investing in your future”)

Non-contrast cardiac magnetic resonance imaging after SARS-CoV2 infection or vaccination in asymptomatic adolescents: insights from the EnIGMA study

Background

Myocarditis after SARS-CoV2 infection or vaccination is rare, but seems to be relatively more frequent in young population. Cardiac magnetic resonance (CMR) T2 weighted sequences have the potential to detect subclinical myocarditis. However, there is paucity of data on the potential myocardial involvement after SARS-CoV2 infection or vaccination in asymptomatic adolescents.

Purpose

To evaluate the presence of subclinical myocardial damage in adolescents who were infected with SARS-CoV2 or vaccinated against SARS-CoV2 using non-contrast CMR imaging.

Methods

Asymptomatic adolescents enrolled in the “Early ImaginG Markers of unhealthy lifestyles in Adolescents” (EnIGMA) project were scanned using a 3-Tesla CMR scanner between March 2021 and October 2021. CMR scans included CINE imaging and myocardial T2-mapping sequences. SARS-CoV2 IgG antibody testing was performed in capillary blood samples, and date of confirmed SARS-CoV2 infection and/or vaccination if any was collected. Participants were assigned to three different groups according to SARS-CoV2 status: Group 1 (non-infected and non-vaccinated), Group 2 (infected and non-vaccinated), and Group 3 (vaccinated, independently of past infection status). CMR images were analyzed by experienced observers blinded to adolescent's SARS-CoV2 status. ANOVA and multiple regression analysis, together with correlation coefficients, were used to study between-group differences and associations among variables of interest.

Results

A total of 115 adolescents with a mean age of 16.0 years (standard deviation (SD)=0.4), 54% girls, completed the CMR study and SARS-CoV2 data successfully, and were assigned to Group 1 (n=72), Group 2 (n=22), and Group 3 (n=21). Left and right ventricular ejection fraction (LVEF/RVEF) did not significantly differ among groups: mean LVEF was 62.8% (SD=4.1), 63.0% (SD=3.7) and 60.9% (SD=3.9) [p=0.12] and mean RVEF was 56.5% (SD=4.2), 56.5% (SD=5.5) and 54.5% (SD=5.1) [p=0.23] in Groups 1, 2 and 3, respectively. Similarly, there were no between-group significant differences in myocardial T2 relaxation values: mean T2 values were 44.1 ms (SD=2.2), 44.1 ms (SD=1.8) and 44.4 ms (SD=1.9) in Groups 1, 2, and 3, respectively (p=0.63) (Figure 1). No differences were found either after adjusting for age and gender. Median time (interquartile range) from date of infection or vaccination to CMR acquisition was 133 (121) days and 28 (38) days in Group 2 and Group 3, respectively. No correlation between time from infection/vaccination to CMR acquisition and T2 values was detected (Figure 2).

Conclusions

This observational study did not find evidence of subclinical myocardial involvement after SARS-CoV2 infection or vaccination in asymptomatic adolescents, as assessed with T2-mapping magnetic resonance imaging.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Instituto de Salud Carlos III (ISCIII)-Fondo de Investigaciόn Sanitaria.European Regional Development Fund/European Social Fund (“A way to make Europe”/“Investing in your future”.

Sleep duration and its association with cardiometabolic outcomes among adolescents enrolled in the SI Program in Spain

Background

Sleep duration has been inversely associated with increased prevalence of overweight/obesity in childhood and adolescence [1, 2]. However, large studies linking over time objectively measured sleep duration and other cardiometabolic outcomes in adolescence are lacking.

Purpose

To evaluate sleep duration and its association with cardiometabolic outcomes in a large cohort of adolescents aged 12 to 16 years from the SI! Program for Secondary Schools trial in Spain [3], together with its relationship with sociodemographic variables.

Methods

Seven-day actigraphic recording was performed in 1229 adolescents at baseline (49.7% girls; 12.5 (0.4) years), 1058 at first follow-up (51.1% girls; 13.9 (0.4) years), and 895 at second follow-up (52.3% girls; 15.8 (0.4) years). Three groups were defined: very short sleep duration (&lt;7 h), short sleep duration (7 to 8 h), and reference sleep duration (≥8 h) [4]. Overweight/obesity were determined according to BMI age- and sex-adjusted percentiles. Continuous Metabolic Syndrome (MetS) score was calculated as the sum of the age-and-gender specific z-scores of mean arterial pressure (MAP) (MAP = ((systolic BP − diastolic BP)/3) + diastolic BP), waist circumference, and fasting blood measures of high-density lipoprotein cholesterol (HDL-c) levels multiplied by −1, triglycerides, and glucose levels [5]. Associations between sleep duration and cardiometabolic outcomes were analyzed using generalized linear and Poisson distribution adjusted models.

Results

At 12 years of age, only 34.2% of the adolescents met sleep recommendations (sleep hours ≥8), and this percentage decreased with advancing age (23.4% and 19.4% at approximately 14 and 16 years of age, respectively) (Figure 1). Boys and individuals from migrant families tended to sleep shorter. Moreover, sleep duration was directly associated with sleep quality and efficiency. After adjusting for potential cofounders, very short sleepers (&lt;7h) had a higher prevalence ratio (PR) of overweight/obesity at baseline (PR: 1.21 [95% CI: 1.16 to 1.27]) and at first follow-up (PR: 1.72 [95% CI: 1.08 to 2.74]) than the reference group (≥8 h) (Figure 2). Similarly, very short sleepers showed higher mean MetS scores at baseline (0.98 [95% CI: 0.43 to 1.54] and at first follow-up (0.76 [95% CI: 0.24 to 1.27]) as compared with the reference group. Short sleepers showed similar trends with associations of weaker magnitude, as they were the overall associations between sleep duration and cardiometabolic outcomes at second follow-up.

Conclusions

Most adolescents, and particularly those with a migrant background, did not meet sleep recommendations. Moreover, a shorter sleep duration was associated with cardiometabolic outcomes, particularly at 12 and 14 years of age and when sleeping less than 7 hours. Health promotion programs should emphasize the importance of good sleep habits.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): 1. Fundaciό la Maratό de TV3.2. SHE Foundation and “la Caixa” Foundation.

Subclinical Atherosclerosis in Young, Socioeconomically Vulnerable Hispanic and Non-Hispanic Black Adults

BACKGROUND

Non-Hispanic Black persons are at greater risk of cardiovascular (CV) events than other racial/ethnic groups; however, their differential vulnerability to early subclinical atherosclerosis is poorly understood.

OBJECTIVES

This work aims to study the impact of race/ethnicity on early subclinical atherosclerosis in young socioeconomically disadvantaged adults.

METHODS

Bilateral carotid and femoral 3-dimensional vascular ultrasound examinations were performed on 436 adults (parents/caregivers and staff) with a mean age of 38.0 ± 11.1 years, 82.3% female, 66% self-reported as Hispanic, 34% self-reported as non-Hispanic Black, and no history of CV disease recruited in the FAMILIA (Family-Based Approach in a Minority Community Integrating Systems-Biology for Promotion of Health) trial from 15 Head Start preschools in Harlem (neighborhood in New York, New York, USA). The 10-year Framingham CV risk score was calculated, and the relationship between race/ethnicity and the presence and extent of subclinical atherosclerosis was analyzed with multivariable logistic and linear regression models.

RESULTS

The mean 10-year Framingham CV risk was 4.0%, with no differences by racial/ethnic category. The overall prevalence of subclinical atherosclerosis was significantly higher in the non-Hispanic Black (12.9%) than in the Hispanic subpopulation (6.6%). After adjusting for 10-year Framingham CV risk score, body mass index, fruit and vegetable consumption, physical activity, and employment status, non-Hispanic Black individuals were more likely than Hispanic individuals to have subclinical atherosclerosis (OR: 3.45; 95% CI: 1.44-8.29; P = 0.006) and multiterritorial disease (P = 0.026).

CONCLUSIONS

After adjustment for classic CV risk, lifestyle, and socioeconomic factors, non-Hispanic Black younger adults seem more vulnerable to early subclinical atherosclerosis than their Hispanic peers, suggesting that the existence of emerging or undiscovered CV factors underlying the residual excess risk (Family-Based Approach in a Minority Community Integrating Systems-Biology for Promotion of Health [FAMILIA (Project 2)]; NCT02481401).

Cardiovascular health trajectories among adolescents enrolled in the SI Program in Spain: a longitudinal study

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): 1. Fondo de Investigación Sanitaria- Instituto de Salud Carlos III2. SHE Foundation and “la Caixa” Foundation.

Background

There is a paucity of data on adolescents’ cardiovascular health (CVH) profiles and longitudinal trajectories.

Purpose

To identify CVH trajectories in a large cohort of Spanish adolescents aged 12 to 16 years and their relationship with sociodemographic variables.

Methods

This study collected data at approximately 12, 14 and 16 years of age from 1078 adolescents attending 24 secondary schools enrolled in the SI! Program for Secondary Schools trial in Spain [1]. The status (non-ideal = 0 points; ideal = 1 point) of each CVH individual metric (smoking status, body mass index, physical activity, dietary habits, blood pressure, total cholesterol, and blood glucose) was determined following the criteria established by the American Heart Association [2]. An overall CVH score was constructed summing the number of ideal CVH metrics (ranged thus from 0 to 7 points), and poor, intermediate, or ideal overall CVH score was defined as ≤3, 4-5, or 6-7 ideal metrics, respectively [3]. CVH trajectories were identified using latent class trajectory modeling with the Stata command traj [4]. Next, individuals were assigned to the trajectory group they were most likely to belong based on the posterior predictive probabilities of group membership.

Results

Among 1078 adolescents with a baseline mean (SD) age of 12.5 (0.4) years, 48.5% girls, four distinct CVH trajectory groups were identified: low-stable (56 adolescents [5.0%]), low-rise (232 [21.3%]), intermediate-decline (136 [18.2%]) and intermediate-stable (654 [55.5%]) (Figure 1). Adolescents belonging to the intermediate-stable and the low-stable trajectories showed the highest and lowest overall CVH mean (SD) scores at baseline [4.8 (0.8) and 2.6 (0.9), respectively] (Figure 2). Similar differences were observed for the analysis of overall CVH score as a categorical variable (poor, intermediate, ideal). Sociodemographic differences between CVH trajectories were identified, with the highest proportion of girls, high-income and non-migrant families within the intermediate-stable trajectory.

Conclusions

In a large cohort of adolescents, ~55% of adolescents showed an intermediate CVH score at baseline and did not decline over time. The characterization of distinct CVH trajectories and sociodemographic differences between them may help tailoring health promotion programs for adolescents.

Clinical Validation of a 3-Dimensional Ultrafast Cardiac Magnetic Resonance Protocol Including Single Breath-Hold 3-Dimensional Sequences

OBJECTIVES

This study sought to clinically validate a novel 3-dimensional (3D) ultrafast cardiac magnetic resonance (CMR) protocol including cine (anatomy and function) and late gadolinium enhancement (LGE), each in a single breath-hold.

BACKGROUND

CMR is the reference tool for cardiac imaging but is time-consuming.

METHODS

A protocol comprising isotropic 3D cine (Enhanced sensitivity encoding [SENSE] by Static Outer volume Subtraction [ESSOS]) and isotropic 3D LGE sequences was compared with a standard cine+LGE protocol in a prospective study of 107 patients (age 58 ± 11 years; 24% female). Left ventricular (LV) mass, volumes, and LV and right ventricular (RV) ejection fraction (LVEF, RVEF) were assessed by 3D ESSOS and 2D cine CMR. LGE (% LV) was assessed using 3D and 2D sequences.

RESULTS

Three-dimensional and LGE acquisitions lasted 24 and 22 s, respectively. Three-dimensional and LGE images were of good quality and allowed quantification in all cases. Mean LVEF by 3D and 2D CMR were 51 ± 12% and 52 ± 12%, respectively, with excellent intermethod agreement (intraclass correlation coefficient [ICC]: 0.96; 95% confidence interval [CI]: 0.94 to 0.97) and insignificant bias. Mean RVEF 3D and 2D CMR were 60.4 ± 5.4% and 59.7 ± 5.2%, respectively, with acceptable intermethod agreement (ICC: 0.73; 95% CI: 0.63 to 0.81) and insignificant bias. Both 2D and 3D LGE showed excellent agreement, and intraobserver and interobserver agreement were excellent for 3D LGE.

CONCLUSIONS

ESSOS single breath-hold 3D CMR allows accurate assessment of heart anatomy and function. Combining ESSOS with 3D LGE allows complete cardiac examination in <1 min of acquisition time. This protocol expands the indication for CMR, reduces costs, and increases patient comfort.

Beneficial effect of colchicine in an animal model of atherosclerosis

Background

Atherosclerosis is a chronic inflammatory disease and colchicine demonstrated clinical benefits in the treatment of stable coronary artery disease.

Purpose

Our aim was to assess the anti-inflammatory effects of colchicine on atherosclerotic vascular disease.

Methods

Atherosclerosis was induced in the abdominal aorta of 20 rabbits with high-cholesterol diet and balloon endothelial denudation. The study protocol lasted 36 weeks. After 18 weeks rabbits were randomized to receive either colchicine or placebo. Two animals died in each group. At randomization and at the end of the study, all animals underwent MRI and positron 18F-FDG PET/CT. In this post-hoc subgroup analyses, animals of each group in the first quartile of cholesterol levels were excluded. For MRI plaque volume values were expressed as Normalized Wall Index (NWI) and for 18F-FDG PET/CT values were expressed as mean maximum standard uptake (meanSUVmax). Statistical comparisons were made by using the Mann-Whitney U test for unpaired data and Wilcoxon signed-rank test for paired data.

Results

Results are summarized in Table 1. Animals with higher levels of cholesterol (6 per group) showed significant differences in favor to colchicine group, both as NWI at the end of the protocol 0.47 (IQR 0.05) in the colchicine group versus 0.52 (IQR 0.03) in the placebo; p=0.01] and as relative increase in meanSUVmax [−4.0% (IQR 30.1) in the colchicine group versus 35.1 (IQR 59.0) in the placebo; p 0.041] (Figure 1).

Conclusions

Colchicine may stabilize atherosclerotic plaque by reducing inflammatory activity and plaque burden.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): This work was supported by a grant from the Sociedad Española de Cardiología and a grant from the Carlos III Institute of Health of Spain and Fondo Europeo de Desarrollo Regional (FEDER, “Una manera de hacer Europa”)

Grenada Heart Project-Community Health ActioN to EncouraGe healthy BEhaviors (GHP-CHANGE): A randomized control peer group-based lifestyle intervention

BACKGROUND

The incidence of cardiovascular (CV) risk factors is increasing globally, with a disproportionate burden in the low and low-middle income countries (L/LMICs). Peer support, as a low-cost lifestyle intervention, has succeeded in managing chronic illness. For global CV risk reduction, limited data exists in LMICs.

AIM

The GHP-CHANGE was designed as a community-based randomized trial to test the effectiveness of peer support strategy for CV risk reduction in the island of Grenada, a LMIC.

METHODS

We recruited 402 adults from the Grenada Heart Project (GHP) Cohort Study of 2827 subjects with at least two CV risk factors. Subjects were randomized in a 1:1 fashion to a peer-group based intervention group (n = 206) or a self-management control group (n = 196) for 12 months. The primary outcome was the change from baseline in a composite score related to Blood pressure, Exercise, Weight, Alimentation and Tobacco (FBS, Fuster-BEWAT Score), ranging from 0 to 15 (ideal health = 15). Linear mixed-effects models were used to test for intervention effects.

RESULTS

Participants mean age was 51.4 years (SD 14.5) years, two-thirds were female, and baseline mean FBS was 8.9 (SD 2.6) and 8.5 (SD 2.6) in the intervention and control group, respectively (P = .152). At post intervention, the mean FBS was higher in the intervention group compared to the control group [9.1 (SD 2.7) vs 8.5 (SD 2.6), P = .028]. When balancing baseline health profile, the between-group difference (intervention vs. control) in the change of FBS was 0.31 points (95% CI: -0.12 to 0.75; P = .154).

CONCLUSIONS

The GHP-CHANGE trial showed that a peer-support lifestyle intervention program was feasible; however, it did not demonstrate a significant improvement in the FBS as compared to the control group. Further studies should assess the effects of low-cost lifestyle interventions in LMICs.

Low-Dose Aspirin for Primary Prevention of Cardiovascular Disease: Use Patterns and Impact Across Race and Ethnicity in the Southern Community Cohort Study

Background

Data are limited on use patterns of low‐dose aspirin and its role for primary prevention of cardiovascular disease (CVD) in different racial and ethnic groups.

Methods and Results

Overall, 65 231 non‐Hispanic black and white people aged 40 to 79 years with no history of CVD enrolled from 2002 through 2009 in the SCCS (Southern Community Cohort Study). At cohort entry, the simplified Framingham 10‐year CVD risk was calculated, and data related to low‐dose aspirin use and clinical and socioeconomic covariates were collected. Race‐ and ethnicity‐specific adjusted odds ratios for characteristics of low‐dose aspirin users and hazard ratios for ischemic cardiac death according to aspirin use were calculated using multivariate logistic and Cox regression models. Black participants were less likely to take low‐dose aspirin compared with white participants, regardless of CVD risk and covariates (adjusted odds ratio: 0.79; 95% CI, 0.75–0.82). Over a median follow‐up of 11.3 years, low‐dose aspirin use was associated with a trend toward decreased risk of ischemic cardiac death in white participants (adjusted hazard ratio: 0.86; 95% CI, 0.68–1.10), especially in women (adjusted hazard ratio: 0.72; 95% CI, 0.51–1.02), but not in black participants (adjusted hazard ratio: 1.18; 95% CI, 0.98–1.40). Similar trends were observed when the analysis was restricted to high‐risk individuals aged 50 to 69 or 50 to 59 years, ages for which guidelines consider aspirin for CVD primary prevention.

Conclusions

Low‐dose aspirin use for primary prevention of CVD is lower among black than white patients. Its use might be associated with a disparate impact on ischemic cardiac death according to race and ethnicity. Although additional studies are required, these findings provide no evidence of a beneficial effect of aspirin among black patients for CVD primary prevention.

P3108Microcirculation injury is involved in anthracycline-induced cardiac toxicity

Background/Introduction

Cardiotoxicity (CT) is a major concern for cancer patients receiving anthracyclines. While the effect of anthracyclines on cardiomyocytes is well established, its impact on myocardial microcirculation has not been characterized.

Purpose

To evaluate the effect of low and high cumulative doses of doxorubicin (doxo) on anatomical and functional vasculature status evaluated by serial invasive Coronary Flow Reserve (CFR) and Cardiac Magnetic Resonance (CMR)-based quantitative perfusion in a large animal model.

Methods

Large-white male pigs (n=15, 30 kg) were distributed in 2 doxo regimes: Group 1) high cumulative dose (5 biweekly intracoronary (i.c) injections of 0.45 mg/kg of doxo) followed-up until week 16 (a time when severe left ventricular systolic dysfunction is present) and then sacrificed (N=5); Group 2) low cumulative dose of doxo (3 biweekly i.c. doses) followed-up until week 16 and then sacrificed (N=5)). Group 3) pigs sacrificed at 6 weeks (2 weeks after third doxo dose), N=5. Invasive catheter-based CFR was evaluated after i.c papaverine (0.5 mg/kg) while CMR quantitative rest perfusion maps were obtained after intravenous injection of gadolinium. CFR and CMR were performed before doxo, and at 0, 2, 4, 6 and 16 weeks thereafter. Cardiac vessels were evaluated ex vivo with trichrome staining. Statistical analysis was performed using one-way ANOVA with multiple pairwise comparisons (vs. baseline) and Bonferroni corrected p-value.

Results

CFR and CMR-quantitative myocardial perfusion were non-significantly reduced after 3 doxo doses despite myocardial vasculature was overtly injured on histology at this timepoint. Animals receiving 5 doxo doses suffered a progressive deterioration of CFR and CMR-perfusion until week 16 (1.41±0.23 vs 3.71±0.94 at baseline [p=0.014] and 65.4±18.2 ml/100g/min vs 154.9±56.3 ml/100g/min at baseline [p=0.046], respectively). At 16 weeks histology revealed extensive microvascular damage with media layer involvement and perivascular fibrosis. Pigs receiving 3 doxo doses showed less pronounced CFR reduction on long-term follow-up (3.13±0.82 vs 3.69±1.57 at baseline [p>0.05] but overt CMR-perfusion reduction (138.3±11.9 vs 197.8±37.1 at baseline [p=0.045]). On histology, damage of vasculature including arterioles was evidenced to a lesser extent than in the high cumulative doxo dose group with mild microvascular disruption and smooth muscle vacuolization.

Conclusions

Doxorubicin results in a progressive damage of the myocardial microcirculation. Even low cumulative doxo doses (resulting in no overt left ventricular dysfunction) results in vascular damage. The microcirculation status may serve as an early marker of doxorubicin cardiotoxicity.

P6423Cardioprotective effect of metoprolol in myocardial ischemic/reperfusion injury: the role of total ischemic time

Background

Metoprolol administration before reperfusion has shown relevant cardioprotective effect in the AMI in preclinical setting. However, the translation to clinical arena has controversial results. The time at drug administration in the context of total duration of ischemia have been pointed as fundamental aspects to be studied.

Purpose

evaluate the cardioprotective effect of metoprolol administration regarding to the total time of ischemia, using a swine model of reperfused AMI.

Methods

50 pigs were subjected to 3 temporary protocols of left anterior descending (LAD) coronary artery occlusion followed by reperfusion. 30 pigs undergoing 40 minutes of ischemia (T40) were randomized 2:1 to intravenous placebo or metoprolol administrated 20 minutes after LAD occlusion.10 pigs undergoing 20 minutes of ischemia 20 (T20) and 10 pig undergoing 60 minutes of ischemia 60 (T60) were randomized 1:1 to intravenous placebo or metoprolol. Before reperfusion a CT study was performed to stablish the area at risk (AAR). CMR was performed at 7 and 45 days after AMI.

Results

48 subjects comprised the 7-day CMR follow-up (1 dead in the metoprolol T40,1 dead in the placebo T40) while 41 subjects comprised the 45-day CMR follow-up (5 deceases in the placebo T40 group, and 2 in the placebo T60 group). AAR was similar among groups (Table 1, Panel B). At 7-day follow-up, IS washigher in the placebo groups as compared to the metoprolol groups, but only reach significant difference in the T40 (29,67% vs. 22,85%, p=0.04, Table 1, Panel A). LVEF measured at 45-day follow-up was higher in the metoprolol groups vs the control groups, but the differences were statistically significance in the T40 (32,76% vs 39,68% p=0.04, Panel C).

Table 1 20 mins. Ischemia (T20) 40 mins. Ischemia (T40) 60 mins. Ischemia (T60) P PLACEBO METOPROL P value PLACEBO METOPROL P value PLACEBO METOPROL P value AAR 32 (28.14–37.89) 33.41 (28.12–38.32) 0.82 32.99 (29.25–35.83) 31.42 (26.94–37.83) 0.72 33.28 (29.68–41.14) 33.93 (28.17–40.69) 0.80 0.98 IS 1.96 (0.92–3.61) 0 (0–0.65) 0.063 29.67 (27.23–35.35) 22.85 (14.53–28.10) 0.042 36.21 (33.55–40.91) 33.78 (39.36–35.39) 0.31 <0.001 LVEF 54.36 (49.75–58.97) 55.34 (53.14–60.88) 0.66 32.76 (26.91–36.10) 39.68 (35.45–45.28) 0.023 26.13 (22.40–31.25) 32.99 (31.32–35.19) 0.071 <0.001 Values are median (interquartile range). Bold indicates statistical significance. AAR = Area at Risk (% of Left ventricular). IS = Infartc Size (% of Left ventricular). LVEF = Left ventricular ejection fraction (%).

Conclusions

Metoprolol administrated early before reperfusion reduced IS and improved medium-term LVEF compared to placebo. But only T40 receiving metoprolol shownsignificant protection vs placebo. These findings suggest a relevant effect of metoprolol ischemic/reperfusion injury, but depending on the total ischemic time, establishing a potential temporary cardioprotection opportunity window.

Rationale and design of the school-based SI! Program to face obesity and promote health among Spanish adolescents: A cluster-randomized controlled trial

Unhealthy habits in adolescents are increasing at an alarming rate. The school offers a promising environment in which to implement effective preventive strategies to improve adolescents' lifestyle behaviors. The SI! Program is a multilevel multicomponent school-based health-promotion intervention aimed at all stages of compulsory education in Spain. We present the study design of the SI! Program for Secondary Schools, targeting adolescents aged 12 to 16 years.

AIM

The main goal of this study is to evaluate the impact of the SI! Program educational intervention on adolescent lifestyle behaviors and health parameters.

METHODS

The study was designed as a cluster-randomized controlled intervention trial and enrolled 1326 adolescents from 24 public secondary schools in Spain, together with their parents/caregivers. Schools and their students were randomly assigned to the intervention group (the SI! curriculum-based educational program over 2 or 4 academic years) or to the control group (usual curriculum). The primary endpoint will be the change from baseline at 2-year and 4-year follow-up in the composite Ideal Cardiovascular Health (ICH) score, consisting of four health behaviors (body mass index, dietary habits, physical activity, and smoking) and three health factors (blood pressure, total cholesterol, and glucose). Secondary endpoints will include 2-year and 4-year changes from baseline in ICH score subcomponents, the Fuster-BEWAT health scale, adiposity markers (waist circumference and body composition), polyphenol and carotenoid intake, and emotion management.

DISCUSSION

The overarching goal of the SI! Program is to instill healthy behaviors in children and adolescents that can be sustained into adulthood. The SI! Program for Secondary School is a comprehensive health-promotion intervention targeting 12-16-year-old adolescents and their immediate environment. The present study addresses the optimal timing and impact of the educational intervention on health in adolescence.

Children Present a Window of Opportunity for Promoting Health: JACC Review Topic of the Week

Cardiovascular disease is the leading cause of death and disability in the world, largely because of risk factors modifiable by changes in behavior. There is evolving evidence that our behavior as adults has its roots in the environment that we live in from early childhood. Early sustained multicomponent educational programs focused on health promotion in children may represent a window of opportunity to potentially prevent disease in adulthood. The integration of school-based, family-based, and community-based strategies, along with the support of public policies, are likely necessary for the success of these programs. In this review, the authors describe the future of promoting health. Specifically: 1) reasons why children should be a focus for health promotion (alarming trends of risk factors, association between unhealthy factors and subclinical disease, and cost-effectiveness); 2) strategies for health promotion in children (school-based, family-based, and community-based approaches) along with legislative efforts; and 3) research gaps are discussed.

Systolic flow displacement using 3D magnetic resonance imaging in an experimental model of ascending aorta aneurysm: impact of rheological factors

OBJECTIVES

The impact of systolic flow displacement on the development and progression of ascending aorta dilatation in aortic valve disease is a matter of controversy. Our objective was to study the association between rheological stimuli and development of aortic dilatation in a large animal model of supravalvular aortic stenosis and eccentric flow.

METHODS

Twenty-four pigs weighing 10-14 kg were randomly allocated (ratio 2:1) to either restrictive ascending aortic banding or sham operation. Aortic diameter and systolic flow displacement were assessed by three-dimensional phase-contrast magnetic resonance imaging at 6 and 18 weeks after surgery. Twenty pigs (n = 14, banded vs n = 6, sham) completed full imaging protocol and were included in the analysis. After the last follow-up, a subset of 14 animals was sacrificed for histological analysis.

RESULTS

All banded animals developed significant progressive aortic dilatation both at 6 and 18 weeks, compared with sham-operated pigs: 34.3 ± 4.8 vs 21.4 ± 2.7 mm at 6 weeks (P < 0.001); and 50.0 ± 8.4 vs 38.0 ± 8.3 mm at 18 weeks (P = 0.002). The peak gradient at 6 weeks showed a trend to positively correlate with aortic diameter at 18 weeks (R = 0.50, P = 0.06), whereas the systolic flow displacement at 6 weeks correlated better with aortic diameter at 18 weeks (R = 0.59, P = 0.02). The aortic wall thickness was significantly decreased in the anterior aortic section in banded, compared with sham-operated, pigs (1.5 ± 0.4 vs 2.0 ± 0.1 mm, respectively; P = 0.03). In addition, banded pigs showed a higher degree of cystic medial necrosis and elastin fibre fragmentation, compared with sham-operated animals.

CONCLUSIONS

In this preclinical model of supravalvular aortic stenosis and eccentric flow, we found that systolic flow displacement at earlier stages is positively correlated with the degree of aortic dilatation during follow-up as assessed by three-dimensional phase-contrast magnetic resonance imaging. If our findings are confirmed in further studies, this imaging parameter might be useful to identify those subjects with aortic valve disease who are at risk of developing aortic dilatation at a later stage.