Ethnic differences in coronary plaque and epicardial fat volume quantified using computed tomography

Synergistic Effect of the CHA2DS2-VASc Score and Left Atrial Epicardial Adipose Tissue Volume on Predicting Atrial Fibrillation Recurrence After Ablation

Objective

The CHA2DS2-VASc score and left atrial epicardial adipose tissue (LA-EAT) volume have been identified as potential risk factors for atrial fibrillation (AF) recurrence after ablation. However, there is currently a lack of research specifically examining the interaction between these two AF risk factors. This study aims to evaluate the predictive potential of combining CHA2DS2-VASc score and LA-EAT volume in predicting recurrence in patients with AF who undergo ablation.

Methods

The study encompassed a cohort of 507 patients who underwent ablation for AF finally. Follow-up assessments were conducted 1, 3, 6, and 12 months after ablation, including clinical evaluation, a 12-lead ECG, and 24-hour Holter monitoring. Recurrence was characterized by symptomatic or asymptomatic AF episodes or atrial tachycardia lasting more than 30 seconds, as evidenced by any ECG following the 3-month BP. Patients were stratified into groups based on the defined cut-off values of CHA2DS2-VASc score and LA-EAT volume. Cox regression analysis was employed to estimate the risk factor of AF recurrence after ablation. The interaction between CHA2DS2-VASc score and LA-EAT volume was assessed using the relative excess risk due to interaction (RERI), attributable proportion (AP), and synergy index (SI).

Results

140 patients experienced AF recurrence after ablation during the follow-up period. Multivariable Cox regression analysis demonstrated that CHA2DS2-VASc score and LA-EAT volume were independent risk factors for AF recurrence. Patients with higher CHA2DS2-VASc score and LA-EAT volume exhibited a higher risk of recurrence than those with lower score and volume. Furthermore, a significant synergistic interaction existed between CHA2DS2-VASc score and LA-EAT volume. The LA-EAT volume and clinical model combination improved the predictive value reclassification, and discriminant abilities improved significantly.

Conclusion

There is a significant additive interaction between CHA2DS2-VASc score and LA-EAT volume, with the coexistence of both factors significantly increasing the risk of AF recurrence after ablation.

Epicardial adipose tissue, cardiac damage, and mortality in patients undergoing TAVR for aortic stenosis

Computed tomography (CT)-derived Epicardial Adipose Tissue (EAT) is linked to cardiovascular disease outcomes. However, its role in patients undergoing Transcatheter Aortic Valve Replacement (TAVR) and the interplay with aortic stenosis (AS) cardiac damage (CD) remains unexplored. We aim to investigate the relationship between EAT characteristics, AS CD, and all-cause mortality. We retrospectively included consecutive patients who underwent CT-TAVR followed by TAVR. EAT volume and density were estimated using a deep-learning platform and CD was assessed using echocardiography. Patients were classified according to low/high EAT volume and density. All-cause mortality at 4 years was compared using Kaplan-Meier and Cox regression analyses. A total of 666 patients (median age 81 [74-86] years; 54% female) were included. After a median follow-up of 1.28 (IQR 0.53-2.57) years, 11.7% (n = 77) of patients died. The EAT volume (p = 0.017) decreased, and density increased (p < 0.001) with worsening AS CD. Patients with low EAT volume (< 49cm3) and high density (≥-86 HU) had higher all-cause mortality (log-rank p = 0.02 and p = 0.01, respectively), even when adjusted for age, sex, and clinical characteristics (HR 1.71, p = 0.02 and HR 1.73, p = 0.03, respectively). When CD was added to the model, low EAT volume (HR 1.67 p = 0.03) and CD stages 3 and 4 (HR 3.14, p = 0.03) remained associated with all-cause mortality. In patients with AS undergoing TAVR, CT-derived low EAT volume, and high density were independently associated with increased 4-year mortality and worse CD stage. Only EAT volume remained associated when adjusted for CD.

Evaluating Pericoronary Adipose Tissue Attenuation to Predict Cardiovascular Events: A Multicenter Study in East Asians

Background

Pericoronary adipose tissue attenuation (PCATA) is a novel imaging biomarker of pericoronary inflammation associated with coronary artery disease. Several studies have reported the usefulness of PCATA among people of European ethnicity; however, data are lacking concerning those of Asian ethnicity.

Objectives

This multicenter study aimed to evaluate the effect of PCATA on prognosis in East Asian patients.

Methods

Between August 2011 and December 2016, 2,172 patients underwent clinically indicated coronary computed tomography angiography (CTA) at 4 hospitals in Japan. Among them, 1,270 patients were analyzed. PCATA was evaluated using coronary CTA to measure pericoronary adipose tissue density surrounding the 3 major coronary arteries. The outcomes were composite cardiovascular events, including cardiovascular death and acute coronary syndrome; 33 cardiovascular events observed during a median follow-up of 6.0 years (Q1-Q3: 3.6-8.2 years).

Results

Right coronary artery (RCA)-PCATA was significantly higher in patients with cardiovascular events than in those without (-63.7 ± 8.9 HU vs -67.4 ± 9.1 HU, respectively; P = 0.021). High RCA-PCATA was significantly associated with cardiovascular events in a model that included the Hisayama risk score and adverse coronary CTA findings (HR: 1.55; 95% CI: 1.07-2.24; P = 0.019).

Conclusions

High RCA-PCATA showed significant association with future cardiovascular events after adjusting conventional risk factors and adverse coronary CTA findings in East Asian patients who underwent clinically indicated coronary CTA.

Ethnic disparities and its association between epicardial adipose tissue thickness and cardiometabolic parameters

Excessive deposit of epicardial adipose tissue (EAT) were recently shown to be positively correlated with cardiovascular disease (CVD). This study aims to investigate the thickness of EAT and its association with the components of metabolic syndrome among multi-ethnic Malaysians with and without acute coronary syndrome (ACS). A total of 213 patients were recruited, with the thickness of EAT were quantified non-invasively using standard two-dimensional echocardiography. EAT thickness among the Malaysian population was prompted by several demographic factors and medical comorbidities, particularly T2DM and dyslipidaemia. ACS patients have significantly thicker EAT compared to those without ACS (4.1 mm vs 3.7 mm, p = 0.035). Interestingly, among all the races, Chinese had the thickest EAT distribution (4.6 mm vs 3.8 mm), with age (p = 0.04 vs p < 0.001), and overall diastolic blood pressure (p = 0.028) was also found to be associated with EAT thickness. Further study is warranted to investigate its role as a cardiovascular risk marker among Malaysians with ACS.

Epicardial fat volume, an independent risk factor for major adverse cardiovascular events, had an incremental prognostic value to myocardial perfusion imaging in Chinese populations with suspected or known coronary artery disease with a normal left ventricular ejection fraction

Background

Most coronary artery disease (CAD) patients with a normal left ventricular ejection fraction (LVEF) experience a poor prognosis. Single-photon emission computerized tomography (SPECT)-myocardial perfusion imaging (MPI), a routine examination, is useful in assessing risk and predicting major adverse cardiovascular events (MACEs) in populations with suspected or known CAD. SPECT/CT is a "one-stop shop" examination, which, through non-contrast CT, can produce attenuation correction for MPI and obtain information on coronary artery calcium (CAC) and epicardial fat volume (EFV) simultaneously. This study aims to investigate the predictive and incremental value of EFV to MPI for MACE in Chinese populations with suspected or known CAD with a normal LVEF.

Methods and results

We retrospectively studied 290 suspected or known CAD inpatients with a normal LVEF who underwent SPECT/CT between February 2014 and December 2017. Abnormal MPI was defined as a summed stress score ≥4 or summed difference score ≥2. EFV and CAC were calculated using non-contrast CT. The end date of follow-ups was in February 2022. The follow-up information was obtained from the clinical case notes of the patients or reviews of telephone calls. MACE was defined as cardiac death, late coronary revascularization ≥3 months after MPI, non-fatal myocardial infarction, angina-related rehospitalization, heart failure, and stroke. During the 76-month follow-up, the event rate was 32.0% (93/290). Univariate and multivariate Cox regression analyses concluded that high EFV (>108.3 cm3) [hazard ratio (HR): 3.3, 95% CI: 2.1-5.2, P < 0.000] and abnormal MPI (HR: 1.8, 95% CI: 1.1-2.8, P = 0.010) were independent risk factors for MACE. The event-free survival of patients with high EFV was significantly lower than that of the low EFV group (log-rank test P < 0.001). In the subgroup with normal MPI, high EFV was associated with reduced event-free survival (log-rank P < 0.01), with a higher annualized event rate (8.3% vs. 1.9%). Adding high EFV to MPI could predict MACEs more effectively, with a higher concordance index (0.56-0.69, P < 0.01), higher global chi square (7.2-41.4, P < 0.01), positive integrated discrimination improvement (0.10, P < 0.01), and net reclassification index (0.37, P < 0.01).

Conclusions

In Chinese populations with suspected or known CAD with normal LVEF, high EFV was an independent risk factor for MACE after adjusting for traditional risk factors, CAC and MPI. In subgroups with normal MPI, EFV could also improve risk stratification. Adding EFV to MPI had an incremental value for predicting MACE.

Cardiometabolic predictors of high-risk CCTA phenotype in a diverse patient population

Introduction

Low-attenuation non-calcified plaque (LAP) burden and vascular inflammation by pericoronary adipose tissue (PCAT) measured from coronary CT angiography (CCTA) have shown to be predictors of cardiovascular outcomes. We aimed to investigate the relationships of cardiometabolic risk factors including lipoprotein(a) and epicardial adipose tissue (EAT) with CCTA high-risk imaging biomarkers, LAP and vascular inflammation.

Methods

The patient population consisted of consecutive patients who underwent CCTA for stable chest pain and had a complete cardiometabolic panel including lipoprotein(a). Plaque, PCAT and EAT were measured from CT using semiautomated software. Elevated LAP burden and PCAT attenuation were defined as ≥4% and ≥70.5 HU, respectively. The primary clinical end-point was a composite of myocardial infarction, revascularization or cardiovascular death.

Results

A total of 364 consecutive patients were included (median age 56 years, 64% female); the majority of patients were of Hispanic (60%), and the rest were of non-Hispanic Black (21%), non-Hispanic White (6%) and non-Hispanic Asian (4%) race/ethnicity. The prevalence of elevated LAP burden and PCAT attenuation was 31 and 18%, respectively, while only 8% had obstructive stenosis. There were significant differences in plaque characteristics among different racial/ethnic groups (p<0.001). Lipoprotein(a) correlated with LAP burden in Hispanic patients. Patients with elevated LAP were older, more likely to be have diabetes, hypertension, hyperlipidemia and smoke with higher CAC and EAT volume (all P<0.05). Patients with elevated LAP were more likely to develop the primary clinical outcome (p<0.001) but those with elevated PCAT were not (p=0.797).

Conclusion

The prevalence of LAP and PCAT attenuation were 31 and 18%, respectively. Lipoprotein(a) levels correlated with LAP burden in Hispanic patients. Age, male sex, hypertension and hyperlipidemia increased the odds of elevated LAP, which showed prognostic significance.

South Asian ethnicity: What can we do to make this risk enhancer a risk equivalent?

South Asians account for around 25% of the global population and are the fastest-growing ethnicity in the US. This population has an increasing burden of atherosclerotic cardiovascular disease (ASCVD) which is also seen in the diaspora. Current risk prediction equations underestimate this risk and consider the South Asian ethnicity as a risk-enhancer among those with borderline-intermediate risk. In this review, we discuss why the South Asian population is at a higher risk of ASCVD and strategies to mitigate this increased risk.

Coronary artery disease in East and South Asians: differences observed on cardiac CT

Epidemiological studies have observed East Asians (EAs) are significantly less likely to develop or die from coronary artery disease (CAD) compared with Caucasians. Conversely South Asians (SAs) develop CAD at higher rate and earlier age. Recently, a range of features derived from cardiac CT have been identified which may further characterise ethnic differences in CAD. Emerging data suggest EAs exhibit less coronary calcification and high-risk, non-calcified plaque compared with Caucasians on CT, with no difference in luminal stenosis. In contrast, SAs exhibit similar to higher coronary calcification and luminal stenosis, smaller luminal dimensions and more high-risk, non-calcified plaque than Caucasians. Beyond demonstrating ethnic differences in CAD, cardiac CT may enhance and individualise cardiovascular risk stratification in EAs and SAs. While data thus far in EAs have demonstrated calcium score and CT-derived luminal stenosis may incrementally predict cardiovascular risk beyond traditional risk scores, there remains a paucity of data assessing its use in SAs. Future studies may clarify the prognostic value of cardiac CT in SAs and investigate how this modality may guide preventative therapy and coronary intervention of CAD in EAs and SAs.

Epicardial adipose tissue volume and coronary calcification among people living with diabetes: a cross-sectional study

BACKGROUND

Epicardial adipose tissue (EAT) has anatomic and functional proximity to the heart and is considered a novel diagnostic marker and therapeutic target in cardiometabolic diseases. The aim of this study was to evaluate whether EAT volume was associated with coronary artery calcification (CAC) in people living with diabetes, independently of confounding factors.

METHODS

We included all consecutive patients with diabetes whose EAT volume and CAC score were measured using computed tomography between January 1, 2019 and September 30, 2020 in the Department of Diabetology-Endocrinology-Nutrition at Avicenne Hospital, France. Determinants of EAT volume and a CAC score ≥ 100 Agatston units (AU) were evaluated.

RESULTS

The study population comprised 409 patients (218 men). Mean (± standard deviation) age was 57 ± 12 years, and 318, 56 and 35 had type 2 (T2D), type 1 (T1D), or another type of diabetes, respectively. Mean body mass index (BMI) was 29 ± 6 kg/m², mean AET volume 93 ± 38 cm³. EAT volume was positively correlated with age, BMI, pack-year smoking history and triglyceridaemia, but negatively correlated with HDL-cholesterol level. Furthermore, it was lower in people with retinopathy, but higher in men, in Caucasian people, in patients on antihypertensive and lipid-lowering medication, in people with nephropathy, and finally in individuals with a CAC ≥ 100 AU (CAC < 100 vs CAC ≥ 100: 89 ± 35 vs 109 ± 41 cm³, respectively, p < 0.05). In addition to EAT volume, other determinants of CAC ≥ 100 AU (n = 89, 22%) were age, T2D, ethnicity, antihypertensive and lipid-lowering medication, cumulative tobacco consumption, retinopathy, macular edema and macrovascular disease. Multivariable analysis considering all these determinants as well as gender and BMI showed that EAT volume was independently associated with CAC ≥ 100 AU (per 10 cm³ increase: OR 1.11 [1.02-1.20]).

CONCLUSIONS

EAT volume was independently associated with CAC. As it may play a role in coronary atherosclerosis in patients with diabetes, reducing EAT volume through physical exercise, improved diet and pharmaceutical interventions may improve future cardiovascular risk outcomes in this population.

Association of Epicardial Fat Volume With the Extent of Coronary Atherosclerosis and Cardiovascular Adverse Events in Asymptomatic Patients With Diabetes

Epicardial adipose tissue has a paracrine effect, enhancing coronary artery atherosclerotic plaque development. This study evaluated epicardial fat volume (EFV), adipokines, coronary atherosclerosis, and adverse cardiovascular events in a cohort of asymptomatic patients with type 2 diabetes mellitus (T2DM). Epicardial fat volume was calculated using data from computed tomography coronary angiograms. Adipokines and inflammatory cytokines were also assayed and correlated with EFV. Epicardial fat volume was also assessed as a predictor of coronary artery calcium (CAC) score, number of coronary artery plaques, and significant plaque (>50% luminal stenosis). Data from the EFV analysis were available for 221 (85.7%) participants. Median EFV was 97.4 cm³, mean body mass index was 28.1 kg/m², and mean duration of T2DM was 13 years. Statistically significant, but weak, correlations were observed between several adipokines, inflammatory cytokines, and EFV. Epicardial fat volume was a significant univariate (P = .01), but not multivariate, predictor of the number of coronary plaques, but not of CAC score or significant plaque. After a mean follow-up of 22.8 months, 12 adverse cardiovascular events were reported, exclusively in participants with EFV >97.4 cm³. Epicardial fat volume has limited utility as a marker of coronary artery plaque in patients with T2DM and is weakly correlated with adipokine expression.

Epicardial Adipose Tissue: Clinical Biomarker of Cardio-Metabolic Risk

Epicardial adipose tissue (EAT) is part of the visceral adipose tissue (VAT) that surrounds the heart and it is a quantifiable, modifiable, and multifaceted tissue that has both local and systemic effects. When EAT is enlarged, EAT contributes to atherosclerotic cardiovascular disease (ASCVD) risk and plays a role in the development of metabolic syndrome (MetS). In this review, we will discuss the role of EAT in various facets of MetS, including type 2 diabetes mellitus (T2DM) and insulin resistance. We examine the association between EAT and liver steatosis. We also address the correlations of EAT with HIV therapy and with psoriasis. We discuss racial differences in baseline EAT thickness. We conclude that EAT measurement serves as a powerful potential diagnostic tool in assessing cardiovascular and metabolic risk. Measurement of EAT is made less costly, more convenient, and yet accurate and reliable by transthoracic echocardiography. Furthermore, modification of EAT thickness has therapeutic implications for ASCVD, T2DM, and MetS.

Comparison of Coronary Atherosclerotic Plaque Burden and Composition as Assessed on Coronary Computed Tomography Angiography in East Asian and European-Origin Caucasians

Recent evidence suggests plaque morphology evaluated on coronary computed tomography angiography has prognostic implications. East Asians have a lower prevalence of myocardial infarction and cardiovascular mortality compared with European-origin Caucasians. We aimed to compare coronary atherosclerotic burden and plaque composition in a matched cohort of Caucasian and East Asians patients with stable chest pain who underwent computed tomography angiography. Two-hundred symptomatic patients (age 58.8 ± 7.9, male 51%) were matched for age, gender, body mass index, and diabetes (100 each ethnic group). A blinded core-laboratory quantified calcified and noncalcified plaque (NCP) volume and burden. Components of NCP were differentiated by plaque hounsfield unit (HU) thresholds which defined high-risk necrotic core (-30 to 30HU), fibrofatty plaque (31 to 130HU); and low-risk fibrous plaque (131 to 350HU). Composition of NCP components was derived as (NCP component volume/total NCP volume) × 100%. Segment Involvement Score, percent diameter and area stenosis were comparable in both groups. Similarly, there was no difference in the volume and burden of total, calcified and NCP. Compared with Caucasians, East Asians demonstrated lower composition of plaque attenuation corresponding to necrotic core (3.5 vs 5.1%; p = 0.004) and fibrofatty plaque (29.6 vs 37.3%; p = 0.005), and higher fibrous plaque (65.7 vs 57.6%; p = 0.004). On multivariable analysis East Asian ethnicity was independently associated with lower composition of high-risk plaque after adjustment for risk factors and scan parameters. These findings were consistent in a propensity-matched sensitivity-analysis. In conclusion, based on this matched cohort, East Asian ethnicity is associated with significantly less composition of high-risk NCP (necrotic core and fibrofatty plaque) and a higher composition of low-risk fibrous plaque compared with Caucasians; which may confer a lower risk of cardiovascular events.

MRI-based assessment and characterization of epicardial and paracardial fat depots in the context of impaired glucose metabolism and subclinical left-ventricular alterations

OBJECTIVE:

To analyze the associations between epicardial and paracardial fat and impaired glucose tolerance as well as left ventricular (LV) alterations.

METHODS:

400 subjects underwent 3 T MRI and fat depots were delineated in the four chamber-view of the steady-state free precession cine sequence (repetition time: 29.97 ms; echo time 1.46 ms). LV parameters were also derived from MRI. Oral glucose tolerance tests were performed.

RESULTS:

Epi- and paracardial fat was derived in 372 (93%) subjects (220 healthy controls, 100 persons with prediabetes, 52 with diabetes). Epi- and paracardial fat increased from normal glucose tolerance (NGT) to prediabetes and diabetes (7.7 vs 9.2 vs 10.3 cm² and 14.3 vs 20.3 vs 27.4 cm², respectively; all p < 0.001). However, the association between impaired glucose metabolism and cardiac fat attenuated after adjustment, mainly confounded by visceral adipose tissue (VAT). 93 subjects (27%) had LV impairment, defined as late gadolinium enhancement, ejection fraction < 55% or LV concentricity index > 1.3 g ml^-1 . Mean epicardial fat was higher in subjects with LV impairment (11.0 vs 8.1 cm², p < 0.001). This association remained independent after adjustment for traditional risk factors and VAT [β: 1.13 (0.22; 2.03), p = 0.02].

CONCLUSION:

Although epicardial and paracardial fat are increased in prediabetes and diabetes, the association is mostly confounded by VAT. Epicardial fat is independently associated with subclinical LV impairment in subjects without known cardiovascular disease.

ADVANCES IN KNOWLEDGE:

This study contributes to the picture of epicardial fat as a pathogenic local fat depot that is independently associated with MR-derived markers of left ventricular alterations.

Body fat, metabolic syndrome and hyperglycemia in South Asians

The prevalence of overweight and obesity is escalating in South Asian countries. South Asians display higher total and abdominal obesity at a lower BMI when compared to Whites. Consequently, metabolic dysfunction leading to metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM) will account for a majority of the health burden of these countries. In this review, we discuss those factors that contribute to MetS and T2DM in South Asians when compared to whites, focusing on adiposity. Abdominal obesity is the single-most important risk factor for MetS and its predisposition to T2DM. Excessive ectopic fat deposition in the liver (non-alcoholic fatty liver disease) has been linked to insulin resistance in Asian Indians, while the effects of ectopic fat accumulation in pancreas and skeletal muscle need more investigation. South Asians also have lower skeletal muscle mass than Whites, and this may contribute to their higher risk T2DM. Lifestyle factors contributing to MetS and T2DM in South Asians include inadequate physical activity and high intakes of refined carbohydrates and saturated fats. These are reflective of the recent but rapid economic transition and urbanization of the South Asian region. There is need to further the research into genetic determinants of dysmetabolism as well as gene x environment interactions. Collectively, MetS and T2DM have multi-factorial antecedents in South Asians and efforts to combat it through low-cost and socio-culturally appropriate lifestyle interventions need to be supported.

Higher Heart Weight in New Zealand Māori and Pacific Islanders

Heart weight is dependent on sex, age, height, and weight. Although previous autopsy studies showed no differences in heart weight between different ethnic groups, none have examined the New Zealand population of Māori and Pacific Islanders (Polynesians). The presented study compared heart weights between 101 European and 85 Polynesian suicide hanging deaths from New Zealand. Univariate linear regression coefficients for age, male sex, height, body weight, body mass index, and Polynesian ethnicity were positive and significant (P < 0.05). Apart from body mass index, subsequent multivariate analysis showed that all regression coefficients remained positive and significant (P < 0.05). Polynesian ethnicity seemed to be an independent predictor for increased heart weight in the study population. Apart from possible genetic factors, the higher heart weight in Polynesians may have other underlying reasons. Caution is required when interpreting heart weight in cases of sudden natural deaths, especially in this population.