Subclinical Atherosclerosis and Incipient Regional Myocardial Dysfunction in Asymptomatic Individuals

Aortic Characteristic Impedance and Suspected Mild Cognitive Impairment in a Community-Based Healthy Population

BACKGROUND

Aging of the proximal aorta can lead to increased pressure and flow pulsatility in the cerebral microcirculation, which may cause cognitive impairment. This study investigated the association between aortic characteristic impedance (Zc), an indicator of regional stiffness of the proximal aorta, and suspected mild cognitive impairment (MCI), compared with carotid-femoral pulse wave velocity (CFPWV).

METHODS AND RESULTS

A total of 1461 healthy community residents (46.4% men; age range, 35-96 years [mean±SD, 59.9±11.8 years]) without a history of cardiovascular events or stroke were included in the study. Zc was estimated using applanation tonometry and echocardiography. Cognitive function was assessed using the Mini-Mental State Examination. Education-adjusted cut points were used to define suspected MCI. Subjects with suspected MCI (n=493 [33.7%]) had significantly higher Zc and CFPWV than those without. In multivariable analysis, both Zc and CFPWV were inversely associated with Mini-Mental State Examination score. Zc (odds ratio per 1 SD, 1.22 [95% CI, 1.09-1.37] and CFPWV (odds ratio per 1 SD, 1.18 [95% CI, 1.01-1.38]) was also significantly associated with suspected MCI, after adjusting for age, sex, education level, mean arterial pressure, hypertension, diabetes, low-density lipoprotein cholesterol, and smoking status. In joint analysis, Zc was significantly associated with suspected MCI, but CFPWV was not. In the age subgroups of <50 years and 50 to 70 years, only Zc was significantly associated with suspected MCI.

CONCLUSIONS

This study found that Zc was significantly associated with Mini-Mental State Examination score and suspected MCI, especially in younger and middle-aged adults. These findings suggest that Zc may be a useful biomarker for identifying individuals at risk for MCI.

Associations Between Coronary Artery Calcification and Left Ventricular Global Longitudinal Strain and Diastolic Parameters: the ELSA-Brasil Study

Atherosclerosis burden can be evaluated in asymptomatic patients by measuring coronary artery calcification (CAC), whereas the global longitudinal strain (GLS) and diastolic function parameters (mitral E/e' ratio, septal e', and lateral e') are used to evaluate subclinical left ventricular (LV) dysfunction. We investigated whether subjects with CAC (CAC >0 Agatston units) would present with an impairment in LV functional parameters. Among the participants of the ELSA-Brasil cohort free of clinically prevalent cardiovascular disease who performed cardiac computed tomography and echocardiography within the study protocol, we tested whether those with CAC >0 presented with worse GLS and diastolic function parameters. CAC >0 was present in 203 of the 612 included participants (33.17%; age 51.4 ± 8.6 years, 52.1% women). Absolute CAC values did not correlate with GLS (ro = 0.07, p = 0.105) but did so with E/e' (ro = 0.19, p <0.001), septal e' (ro = 0.28, p <0.001), and lateral e' (ro = 0.30, p <0.001), with stronger correlations in men. Those with CAC >0 had worse mitral E/e' ratios (7.75 ± 0.13 vs 7.01 ± 0.09; p ≤0.001), septal e' (8.25 ± 0.15 vs 9.59 ± 0.11 cm/s; p <0.001), and lateral e' (10.13 ± 0.20 vs 11.99 ± 0.14 cm/s; p ≤0.001), respectively. However, these associations were not independent of diabetes, obesity, hypertension, smoking, and low-density lipoprotein cholesterol, persisting only as significant associations of CAC >0 with mitral E/e' ratio and septal e' in men. There is an association between subclinical coronary atherosclerosis and impaired LV functional parameters. These associations are more likely attributed to the presence of common cardiovascular risk factors in the general population. However, in men, it seems to exist as an independent association.

Association between subclinical atherosclerosis and cardiac structure and function-results from the UK Biobank Study

Aims

Heart failure (HF) is a major health problem and early diagnosis is important. Atherosclerosis is the main cause of HF and carotid intima-media thickness (IMT) is a recognized early measure of atherosclerosis. This study aimed to investigate whether increased carotid IMT is associated with changes in cardiac structure and function in middle-aged participants of the UK Biobank Study without overt cardiovascular disease.

Methods and results

Participants of the UK Biobank who underwent CMR and carotid ultrasound examinations were included in this study. Patients with heart failure, angina, atrial fibrillation, and history of myocardial infarction or stroke were excluded. We used multivariable linear regression models adjusted for age, sex, physical activity, body mass index, body surface area, hypertension, diabetes, smoking, ethnicity, socioeconomic status, alcohol intake, and laboratory parameters. In total, 4301 individuals (61.6 ± 7.5 years, 45.9% male) were included. Multivariable linear regression analyses showed that increasing quartiles of IMT was associated with increased left and right ventricular (LV and RV) and left atrial volumes and greater LV mass. Moreover, increased IMT was related to lower LV end-systolic circumferential strain, torsion, and both left and right atrial ejection fractions (all P < 0.05).

Conclusion

Increased IMT showed an independent association over traditional risk factors with enlargement of all four cardiac chambers, decreased function in both atria, greater LV mass, and subclinical LV dysfunction. There may be additional risk stratification that can be derived from the IMT to identify those most likely to have early cardiac structural/functional changes.

Comparison of the Relation of Carotid Intima-Media Thickness With Incident Heart Failure With Reduced Versus Preserved Ejection Fraction (from the Multi-Ethnic Study of Atherosclerosis [MESA])

Increased carotid intima-media thickness (cIMT) is associated with heart failure (HF) in previous studies, but it is not known whether the association of cIMT differs between HF with reduced (HFrEF) versus preserved ejection fraction (HFpEF). We studied 6699 participants (mean age 62 ± 10 years, 47% male, and 38% white) from the Multi-Ethnic Study of Atherosclerosis (MESA) with baseline cIMT measurements. We classified HF events as HFrEF (EF <50%) or HFpEF (EF ≥ 50%) at the time of diagnosis. Cox proportional hazard regression was used to compute hazard ratios (HR), and 95% confidence intervals (CI) for the association between the IMT Z-score (measured maximum IMT of Internal Carotid (IC) and Common Carotid (CC) sites as the mean of the maximum IMT of the near and far walls of right and left sides), and incident HFrEF or HFpEF. Models were adjusted for covariates and interim coronary artery disease (CAD) events. A total of 191 HFrEF and 167 HFpEF events occurred during follow-up. In multivariable analysis, each 1 standard deviation increase in the measured maximum IMT (Z-score) was associated with both HFrEF and HFpEF in the unadjusted and demographically adjusted models [HR, 95% CI 1.57 (1.43 to 1.73)] and [HR, 95% CI 1.61 (1.47 to 1.77)] but not in the fully adjusted models [HR, 95% CI 1.11 (0.96 to 1.28)] and [HR, 95% CI 1.13 (0.98 to 1.30)]. In conclusion, cIMT was significantly associated with incident HF, but the association is partially attenuated with adjustment for demographic factors and becomes non-significant after adjustment for other traditional heart failure risk factors and interim CAD events. There was no difference in the association of IMT measures with HFrEF versus HFpEF.

Association between reduced myocardial contraction fraction and cardiovascular disease outcomes: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

The myocardial contraction fraction (MCF: stroke volume to myocardial volume) is a volumetric measure of left ventricular myocardial shortening. We examined the relationship of MCF, measured by cardiac magnetic resonance imaging (cMRI), to incident cardiovascular (CV) events within the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS

Participants (n = 5000, aged 45-84 years) underwent cMRI.

PRIMARY OUTCOME

CVD events (myocardial infarction, resuscitated cardiac arrest, stroke, coronary heart disease: CHD death, and stroke death).

SECONDARY OUTCOMES

CHD and heart failure (HF) events. Cox proportional hazards regression was used to estimate the hazard ratio (HR) and 95% confidence intervals (CI) for outcomes.

RESULTS

There were 299 incident CVD, 188 CHD, and 151 HF events over 10.2 years. The lowest MCF quartile was associated with an increased risk for incident CVD [HR 2.42, CI: 1.58-3.72], CHD [HR 2.32, CI: 1.36-3.96] and HF events [HR 1.99, CI: 1.15-3.44]. In a model adjusted for demographics, CV risk factors, antihypertensive and lipid-lowering medication use, each standard deviation decrease in MCF was associated with incident CVD [HR 1.42, CI: 1.23-1.64], CHD [HR 1.40, CI: 1.17-1.67] and HF [HR 1.58, CI: 1.30-1.94]. In a subgroup analysis of participants with preserved ejection fraction and without left ventricular hypertrophy, the lowest MCF quartile and each standard deviation decrease in MCF was also associated with an increased risk for incident CVD in fully-adjusted analyses.

CONCLUSIONS

MCF is a novel measure that can be measured using cMRI. In this multi-ethnic cohort, MCF is a measure that can be used to predict incident CVD events.

Coronary Artery Calcium From Early Adulthood to Middle Age and Left Ventricular Structure and Function

Background The relationship of coronary artery calcium (CAC) with adverse cardiac remodeling is not well established. We aimed to study the association of CAC in middle age and change in CAC from early adulthood to middle age with left ventricular (LV) function. Methods CAC score was measured by computed tomography at CARDIA study (Coronary Artery Risk Development in Young Adults) year-15 examination and at year-25 examination (Y25) in 3043 and 3189 participants, respectively. CAC score was assessed as a continuous variable and log-transformed to account for nonlinearity. Change in CAC from year-15 examination to Y25 was evaluated as the absolute difference of log-transformed CAC from year-15 examination to Y25. LV structure and function were evaluated by echocardiography at Y25. Results At Y25, mean age was 50.1±3.6 years, 56.6% women, 52.4% black. In the multivariable analysis at Y25, higher CAC was related to higher LV mass (β=1.218; adjusted P=0.007), higher LV end-diastolic volume (β=0.811; adjusted P=0.007), higher LV end-systolic volume (β=0.350; adjusted P=0.048), higher left atrial volume (β=0.214; adjusted P=0.009), and higher E/e' ratio (β=0.059; adjusted P=0.014). CAC was measured at both year-15 examination and Y25 in 2449 individuals. Higher change in CAC score during follow-up was independently related to higher LV mass index in blacks (β=4.789; adjusted P<0.001), but not in whites (β=1.051; adjusted P=0.283). Conclusions Higher CAC in middle age is associated with higher LV mass and volumes and worse LV diastolic function. Being free of CAC from young adulthood to middle age correlates to better LV function at middle age. Higher change in CAC score during follow-up is independently related to higher LV mass index in blacks.

Left ventricular and proximal aorta coupling in magnetic resonance imaging: aging together?

The importance of aorta-ventricular coupling in cardiovascular disease is recognized but underestimated. The contribution of the age-related decline in ascending aortic function compared with characteristic impedance and total peripheral resistance on left ventricular function and remodeling is poorly studied. Our aim was to evaluate the relation of proximal aortic distensibility and impedance with left ventricular geometry and function in asymptomatic individuals. We prospectively studied 100 subjects (47 men, 53 women, age: 20-84 yr). Aortic strain, distensibility, arch pulse wave velocity, characteristic impedance (Z_c), total peripheral resistance, left ventricular (LV) volumes and mass, wall stress, and peak global circumferential myocardial strain and strain rates were determined by MRI. Central pressures were measured from tonometry. E_a/E_v, an index of vascular-ventricular coupling, and LV wall stress were preserved across age- or aortic-stiffness-stratified groups. Static and pulsatile components of aortic load were differentially associated with age. Increased total vascular resistance was associated with decreased LV strain and increased concentric remodeling [ratio of LV mass to end-diastolic volume (M/V ratio)] in all individuals. In younger individuals (<45 yr), aortic distensibility was related to LV strain and concentric remodeling (M/V ratio), whereas Z_c was related to LV strain and concentric remodeling (M/V ratio) in older individuals (>45 yr). Early age-related stiffening of the ascending aorta is a component of LV afterload subsequently associated with increased aortic impedance and alterations in LV geometry, namely concentric remodeling, decreased myocardial strain, and increased stroke work such that LV wall stress and arterial-ventricular coupling are preserved. NEW & NOTEWORTHY Local flow and deformation can both be assessed with high precision noninvasively in the ascending aorta using MRI. Combined with central pressure measurement, they provide distensibility and impedance and simultaneous reference assessment of left ventricular deformation and geometry, hence a comprehensive evaluation of arterial-ventricular coupling to study physiology and disease.

Association of Age at Menarche With Left Ventricular Diastolic Dysfunction in Middle-Aged Women

BACKGROUND

There is sparse research on whether if early menarche is related to left ventricular (LV) diastolic dysfunction. The present study examined this relationship in Korean women.Methods and Results:In a cross-sectional study we analyzed the records of 18,910 Korean women (≥30 years) who underwent echocardiography as part of a comprehensive health examination. Age at menarche was assessed using standardized, self-administered questionnaires. Presence of LV diastolic dysfunction was determined from the echocardiographic findings. Of the 18,910 women, 3,449 had LV diastolic dysfunction. Age at menarche was inversely associated with prevalence of LV diastolic dysfunction. In a multivariable-adjusted model, odds ratios (95% confidence interval) for LV diastolic dysfunction comparing menarche age to menarche at 15-18 years were 1.77 (1.38-2.27) for <12 years, 1.31 (1.11-1.54) for 12 years, 1.26 (1.11-1.43) for 13 years, and 1.03 (0.91-1.15) for 14 years (P for trend <0.001). Adjusting for body mass index or percent fat mass partially reduced these associations.

CONCLUSIONS

This large study found an inverse relationship between menarche age and LV diastolic dysfunction. Future prospective studies are needed to investigate potential causal relationships.

Carotid Intima-Media Thickness as Surrogate for and Predictor of CVD

Carotid artery intima-media thickness (IMT) is a noninvasive measurement of the artery wall thickness, inclusive of atherosclerotic plaque, obtained using ultrasound imaging. In the MESA (Multi-Ethnic Study of Atherosclerosis) study, IMT measurements are used as a surrogate for subclinical cardiovascular disease and as a variable predictive of cardiovascular events. IMT measurements of the common carotid artery are available in more than 99% of the MESA population and are predictive of cardiovascular events. More importantly, IMT and plaque thickness measurements made in the internal carotid artery and carotid bulb are also available in more than 98% of the population and are also strongly predictive of cardiovascular events. This article reviews the techniques used to obtain the MESA IMT values, compares them to those made in other epidemiological studies, and summarizes how they have been used in the MESA study as both surrogates for and predictors of cardiovascular disease.

Cardiovascular magnetic resonance in an adult human population: serial observations from the multi-ethnic study of atherosclerosis

The Multi-Ethnic Study of Atherosclerosis (MESA) is the first large-scale multi-ethnic population study in the U.S. to use advanced cardiovascular magnetic resonance (CMR) imaging. MESA participants were free of cardiovascular disease at baseline between 2000 and 2002, and were followed up between 2009 and 2011 with repeated CMR examinations as part of MESA. CMR allows the clinician to visualize and accurately quantify volume and dimensions of all four cardiac chambers; measure systolic and diastolic ventricular function; assess myocardial fibrosis; assess vessel lumen size, vessel wall morphology, and vessel stiffness. CMR has a number of advantages over other imaging modalities such as echocardiography, computed tomography, and invasive angiography, and has been proposed as a diagnostic strategy for high-risk populations. MESA has been extensively evaluating CMR imaging biomarkers, as markers of subclinical disease, in the last 15 years for low-risk populations. On a more practical level, some of the imaging biomarkers developed and studied are translatable to at-risk populations. In this review, we discuss the progression of subclinical cardiovascular disease and the mechanisms responsible for the transition to symptomatic clinical outcomes based on our findings from MESA.

Diabetes status modifies the association between carotid intima-media thickness and incident heart failure: The Atherosclerosis Risk in Communities study

AIMS

Increasing carotid intima-media thickness (CIMT) is associated with incident heart failure (HF). We investigated whether this association differs by diabetes status.

METHODS

We characterized 13,590 Atherosclerosis Risk in Communities Study participants free of baseline HF into normal fasting glucose (NFG, glucose <100mg/dl), impaired fasting glucose (IFG, glucose 100-125mg/dl), and type 2 diabetes (T2D, glucose ≥126mg/dl, self-report, or use of diabetes drugs). CIMT was assessed by B-mode ultrasound. Incident HF was defined using ICD-9 or 10 codes from hospitalizations and death certificates. Cox regression was used to estimate hazard ratios (HR) for incident HF, adjusting for age, sex, race, education, hypertension medication, blood pressure, BMI, waist circumference, HDL, LDL, triglycerides, lipid-lowering medication, smoking, alcohol, serum creatinine, and interim CHD.

RESULTS

T2D participants had higher mean CIMT (0.79±0.20mm), compared to IFG (0.75±0.19mm) and NFG (0.70±0.17mm) (p<0.0001). Over 20.6years of median follow-up, 15% developed HF. Rates of HF (per 1000 person-years) were substantially higher for those with T2D (24.7), compared to IFG (7.7) and NFG (5.8). In adjusted analyses, the CIMT-HF association was significantly modified by diabetes status (P_interaction=0.015): for NFG (HR per SD increase in CIMT: 1.27; 95%CI: 1.20-1.34), IFG (HR 1.18; 95%CI: 1.11-1.25) and T2D (HR 1.12; 95%CI: 1.05-1.21).

CONCLUSIONS

CIMT is associated with increased risk of HF, particularly among persons without diabetes. Due to a high absolute risk of HF among adults with T2D, CIMT may be a less reliable predictor.

Left Ventricular Function Across the Spectrum of Body Mass Index in African Americans: The Jackson Heart Study

OBJECTIVES

This study sought to assess whether body mass index (BMI) was associated with subclinical left ventricular (LV) systolic dysfunction in African-American individuals.

BACKGROUND

Higher BMI is a risk factor for cardiovascular disease, including heart failure. Obesity disproportionately affects African Americans; however, the association between higher BMI and LV function in African Americans is not well understood.

METHODS

Peak systolic circumferential strain (ECC) was measured by tagged cardiac magnetic resonance in 1,652 adult African-American participants of the Jackson Heart Study between 2008 and 2012. We evaluated the association between BMI and ECC in multivariate linear regression and restricted cubic spline analyses adjusted for prevalent cardiovascular disease, conventional cardiovascular risk factors, LV mass, and ejection fraction. In exploratory analyses, we also examined whether inflammation, insulin resistance, or volume of visceral adipose tissue altered the association between BMI and ECC.

RESULTS

The proportions of female, nonsmokers, diabetic, and hypertensive participants rose with increase in BMI. In multivariate-adjusted models, higher BMI was associated with worse ECC (β = 0.052; 95% confidence interval: 0.028 to 0.075), even in the setting of preserved LV ejection fraction. Higher BMI was also associated with worse ECC when accounting for markers of inflammation (C-reactive protein, E-selection, and P-selectin), insulin resistance, and volume of visceral adipose tissue.

CONCLUSIONS

Higher BMI is significantly associated with subclinical LV dysfunction in African Americans, even in the setting of preserved LV ejection fraction.

Cardiac Imaging in Heart Failure with Comorbidities

Imaging modalities stand at the frontiers for progress in congestive heart failure (CHF) screening, risk stratification and monitoring. Advancements in echocardiography (ECHO) and Magnetic Resonance Imaging (MRI) have allowed for improved tissue characterizations, cardiac motion analysis, and cardiac performance analysis under stress. Common cardiac comorbidities such as hypertension, metabolic syndromes and chronic renal failure contribute to cardiac remodeling, sharing similar pathophysiological mechanisms starting with interstitial changes, structural changes and finally clinical CHF. These imaging techniques can potentially detect changes earlier. Such information could have clinical benefits for screening, planning preventive therapies and risk stratifying patients. Imaging reports have often focused on traditional measures without factoring these novel parameters. This review is aimed at providing a synopsis on how we can use this information to assess and monitor improvements for CHF with comorbidities.

Subclinical LV Dysfunction Detection Using Speckle Tracking Echocardiography in Hypertensive Patients with Preserved LV Ejection Fraction

BACKGROUND

Early detection of subclinical left ventricular (LV) systolic dysfunction in hypertensive patients is important for the prevention of progression of hypertensive heart disease.

METHODS

We studied 60 hypertensive patients (age ranged from 21 to 49 years, the duration of hypertension ranged from 1 to 18 years) and 30 healthy controls, all had preserved left ventricular ejection fraction (LVEF), detected by two-dimensional speckle tracking echocardiography (2D-STE).

RESULTS

There was no significant difference between the two groups regarding ejection fraction (EF) by Simpson’s method. Systolic velocity was significantly higher in the control group, and global longitudinal strain was significantly higher in the control group compared with the hypertensive group. In the hypertensive group, 23 of 60 patients had less negative global longitudinal strain than −19.1, defined as reduced systolic function, which is detected by 2D-STE (subclinical systolic dysfunction), when compared with 3 of 30 control subjects.

CONCLUSION

2D-STE detected substantial impairment of LV systolic function in hypertensive patients with preserved LVEF, which identifies higher risk subgroups for earlier medical intervention.

Abdominal adiposity, general obesity, and subclinical systolic dysfunction in the elderly: A population-based cohort study

AIMS

General obesity, measured by body mass index (BMI), and abdominal adiposity, measured as waist circumference (WC) and waist-to-hip ratio (WHR), are associated with heart failure and cardiovascular events. However, the relationship of general and abdominal obesity with subclinical left ventricular (LV) dysfunction is unknown. We assessed the association of general and abdominal obesity with subclinical LV systolic dysfunction in a population-based elderly cohort.

METHODS AND RESULTS

Participants from the Cardiovascular Abnormalities and Brain Lesions study underwent measurement of BMI, WC, and WHR. Left ventricular systolic function was assessed by two-dimensional echocardiographic LV ejection fraction (LVEF) and speckle-tracking global longitudinal strain (GLS). The study population included 729 participants (mean age 71 ± 9 years, 60% women). In multivariate analysis, higher BMI (but not WC and WHR) was associated with higher LVEF (β = 0.11, P = 0.003). Higher WC (β = 0.08, P = 0.038) and higher WHR (β = 0.15, P < 0.001) were associated with lower GLS, whereas BMI was not (P = 0.720). Compared with normal WHR, high WHR was associated with lower GLS in all BMI categories (normal, overweight, and obese), and was associated with subclinical LV dysfunction by GLS both in participants without [adjusted odds ratio (OR) 2.0, 95% confidence interval (CI) 1.1-3.6, P = 0.020] and with general obesity (adjusted OR 5.4, 95% CI 1.1-25.9, P = 0.034). WHR was incremental to BMI and risk factors in predicting LV dysfunction.

CONCLUSION

Abdominal adiposity was independently associated with subclinical LV systolic dysfunction by GLS in all BMI categories. BMI was not associated with LV dysfunction. Increased abdominal adiposity may be a risk factor for LV dysfunction regardless of the presence of general obesity.

Patients with Diabetes and Significant Epicardial Coronary Artery Disease Have Increased Systolic Left Ventricular Apical Rotation and Rotation Rate at Rest

OBJECTIVE

The purpose of this study was to determine whether resting myocardial deformation and rotation may be altered in diabetic patients with significant epicardial coronary artery disease (CAD) with normal left ventricular ejection fraction.

DESIGN

A prospective observational study.

SETTING

Diagnosis of epicardial CAD in patients with diabetes.

PATIENTS AND METHODS

Eighty-four patients with diabetes suspected of epicardial CAD scheduled for cardiac catheterization had a resting echocardiogram performed prior to their procedure. Echocardiographic measurements were compared between patients with and without significant epicardial CAD as determined by cardiac catheterization.

MAIN OUTCOME MEASURES

Measurement of longitudinal strain, strain rate, apical rotation, and rotation rate, using speckle tracking echocardiography.

RESULTS

Eighty-four patients were studied, 39 (46.4%) of whom had significant epicardial CAD. Global peak systolic apical rotation was significantly increased (14.9 ± 5.1 vs. 11.0 ± 4.8 degrees, P < 0.001) in patients with epicardial CAD along with faster peak systolic apical rotation rate (90.4 ± 29 vs. 68.1 ± 22.2 degrees/sec, P < 0.001). These findings were further confirmed through multivariate logistic regression analysis (global peak systolic apical rotation OR = 1.17, P = 0.004 and peak systolic apical rotation rate OR = 1.05, P < 0.001).

CONCLUSIONS

Patients with diabetes with significant epicardial CAD and normal LVEF exhibit an increase in peak systolic apical counterclockwise rotation and rotation rate detected by echocardiography, suggesting that significant epicardial CAD and its associated myocardial effects in patients with diabetes may be detected noninvasively at rest.

Left Ventricular Systolic Dysfunction by Longitudinal Strain Is an Independent Predictor of Incident Atrial Fibrillation: A Community-Based Cohort Study

BACKGROUND

The increasing prevalence of atrial fibrillation (AF) represents a public health issue. Identifying new predictors of AF is therefore necessary to plan preventive strategies. We investigated whether left ventricular (LV) systolic dysfunction by global longitudinal strain (GLS), a predictor of cardiovascular events, may predict new-onset AF in a population setting.

METHODS AND RESULTS

Participants (n=675; mean age, 71±9 years; 60% women) in sinus rhythm from the population-based Northern Manhattan Study (NOMAS) underwent 2- and 3-dimensional echocardiography as part of the Cardiac Abnormalities and Brain Lesions (CABL) study. LV systolic function was assessed by LV ejection fraction and speckle-tracking GLS. During a mean follow-up of 63.6±18.7 months, 32 (4.7%) new confirmed cases of AF occurred. Lower GLS (adjusted hazard ratio/unit decrease, 1.22; 95% confidence interval, 1.04-1.43; P=0.015) and increased left atrial volume index (LAVi; adjusted hazard ratio/unit increase, 1.12; 95% confidence interval, 1.07-1.17; P<0.001) were significantly associated with incident AF, whereas LV ejection fraction was not (P=0.176). Abnormal GLS (>-14.7%) was associated with risk of new-onset AF with an adjusted hazard ratio of 3.2 (95% confidence interval, 1.4-7.5; P=0.007). The coexistence of abnormal GLS/abnormal LAVi was associated with a 28.6% incidence of AF (adjusted hazard ratio, 12.1; 95% confidence interval, 3.3-44.8; P<0.001) compared with participants with normal GLS/normal LAVi (AF incidence, 2.0%). AF incidence was intermediate in those with either abnormal GLS or abnormal LAVi (9.3% and 11.1%, respectively). GLS prognostic value for incident AF was incremental over risk factors and LAVi.

CONCLUSIONS

LV systolic dysfunction by GLS was a powerful and independent predictor of incident AF. GLS assessment may improve AF risk stratification in addition to established parameters.

Association of subclinical atherosclerosis using carotid intima-media thickness, carotid plaque, and coronary calcium score with left ventricular dyssynchrony: the multi-ethnic Study of Atherosclerosis

BACKGROUND

The role of atherosclerosis in the progression of global left ventricular dysfunction and cardiovascular events has been well recognized. Left ventricular (LV) dyssynchrony is a measure of regional myocardial dysfunction. Our objective was to investigate the relationship of subclinical atherosclerosis with mechanical LV dyssynchrony in a population-based asymptomatic multi-ethnic cohort.

METHODS AND RESULTS

Participants of the Multi-Ethnic Study of Atherosclerosis (MESA) at exam 5 were evaluated using 1.5T cardiac magnetic resonance (CMR) imaging, carotid ultrasound (n = 2062) for common carotid artery (CCA) and internal carotid artery (ICA) intima-media thickness (IMT), and cardiac computed tomography (n = 2039) for coronary artery calcium (CAC) assessment (Agatston method). Dyssynchrony indices were defined as the standard deviation of time to peak systolic circumferential strain (SD-TPS) and the difference between maximum and minimum (max-min) time to peak strain using harmonic phase imaging in 12 segments (3-slices × 4 segments). Multivariable regression analyses were performed to assess associations after adjusting for participant demographics, cardiovascular risk factors, LV mass, and ejection fraction. In multivariable analyses, SD-TPS was significantly related to measures of atherosclerosis, including CCA-IMT (8.7 ms/mm change in IMT, p = 0.020), ICA-IMT (19.2 ms/mm change in IMT, p < 0.001), carotid plaque score (1.2 ms/unit change in score, p < 0.001), and log transformed CAC+1 (0.66 ms/unit log-CAC+1, p = 0.018). These findings were consistent with other parameter of LV dyssynchrony i.e. max-min.

CONCLUSION

In the MESA cohort, measures of atherosclerosis are associated with parameters of subclinical LV dyssynchrony in the absence of clinical coronary event and left-bundle-branch block.

Proximal aortic distensibility is an independent predictor of all-cause mortality and incident CV events: the MESA study

BACKGROUND

The predictive value of ascending aortic distensibility (AAD) for mortality and hard cardiovascular disease (CVD) events has not been fully established.

OBJECTIVES

This study sought to assess the utility of AAD to predict mortality and incident CVD events beyond conventional risk factors in MESA (Multi-Ethnic Study of Atherosclerosis).

METHODS

AAD was measured with magnetic resonance imaging at baseline in 3,675 MESA participants free of overt CVD. Cox proportional hazards regression was used to evaluate risk of death, heart failure (HF), and incident CVD in relation to AAD, CVD risk factors, indexes of subclinical atherosclerosis, and Framingham risk score.

RESULTS

There were 246 deaths, 171 hard CVD events (myocardial infarction, resuscitated cardiac arrest, stroke and CV death), and 88 HF events over a median 8.5-year follow-up. Decreased AAD was associated with increased all-cause mortality with a hazard ratio (HR) for the first versus fifth quintile of AAD of 2.7 (p = 0.008) independent of age, sex, ethnicity, other CVD risk factors, and indexes of subclinical atherosclerosis. Overall, patients with the lowest AAD had an independent 2-fold higher risk of hard CVD events. Decreased AAD was associated with CV events in low to intermediate- CVD risk individuals with an HR for the first quintile of AAD of 5.3 (p = 0.03) as well as with incident HF but not after full adjustment.

CONCLUSIONS

Decreased proximal aorta distensibility significantly predicted all-cause mortality and hard CV events among individuals without overt CVD. AAD may help refine risk stratification, especially among asymptomatic, low- to intermediate-risk individuals.

Visit-to-visit blood pressure variability is a marker of cardiac diastolic function and carotid atherosclerosis

Background

The associations between visit-to-visit blood pressure (BP) variability and cardiac function and carotid atherosclerosis is not clear.

Methods

Study subjects were 144 subjects (80 were female, aged 73 ± 9 years) who underwent echocardiography and cervical ultrasonography. The ratio of early ventricular filling velocity to early diastolic mitral annular velocity (E/e’), ejection fraction, left ventricular mass index (LVMI), and maximum intima-media thickness (max-IMT) of the carotid artery were compared between the highest (high variability) and lowest (low variability) tertiles of the standard deviation of systolic BP (9.9 ± 3.5 mmHg).

Results

E/e’ and max-IMT were significantly greater in the high variability group than in the low variability group after adjusting for age, sex, baseline systolic BP, and other covariates (high variability vs. low variability; E/e’: 13.03 ± 5.33 vs. 10.66 ± 3.30, multivariate-adjusted difference (β) = 1.82, 95% confidence interval 0.06–3.58; max-IMT: 1.65 ± 0.43 mm vs. 1.42 ± 0.46 mm, β = 0.20 mm, 95% confidence interval 0.03–0.36 mm). There were no significant differences in LVMI or ejection fraction.

Conclusion

These results indicate that high visit-to-visit BP variability is associated with diastolic function and carotid atherosclerosis, and is a possible risk factor for diastolic dysfunction and atherosclerosis.

Quantification of regional myocardial wall motion by cardiovascular magnetic resonance

Cardiovascular magnetic resonance (CMR) is a versatile tool that also allows comprehensive and accurate measurement of both global and regional myocardial contraction. Quantification of regional wall motion parameters, such as strain, strain rate, twist and torsion, has been shown to be more sensitive to early-stage functional alterations. Since the invention of CMR tagging by magnetization saturation in 1988, several CMR techniques have been developed to enable the measurement of regional myocardial wall motion, including myocardial tissue tagging, phase contrast mapping, displacement encoding with stimulated echoes (DENSE), and strain encoded (SENC) imaging. These techniques have been developed with their own advantages and limitations. In this review, two widely used and closely related CMR techniques, i.e., tissue tagging and DENSE, will be discussed from the perspective of pulse sequence development and image-processing techniques. The clinical and preclinical applications of tissue tagging and DENSE in assessing wall motion mechanics in both normal and diseased hearts, including coronary artery diseases, hypertrophic cardiomyopathy, aortic stenosis, and Duchenne muscular dystrophies, will be discussed.

Carotid artery intima-media thickness is closely related to impaired left ventricular function in patients with coronary artery disease: a single-centre, blinded, non-randomized study

Background

Atherosclerosis is the underlying cause of the majority of myocardial infarctions and ischemic strokes. Carotid intima-media thickness (IMT) is a surrogate measure of atherosclerotic cardiovascular disease. Left ventricular (LV) function can be accurately assessed by 2D speckle-tracking strain echocardiography (2D-STE). The aim of this study was to assess the relationship between carotid IMT and LV dysfunction assessed by strain echocardiography in patients with coronary artery disease (CAD).

Methods

Thirty-one patients with symptoms of CAD were examined with coronary angiography, cardiac echocardiography and carotid ultrasound. Layer-specific longitudinal strains were assessed from endo-, mid- and epicardium by 2D-STE. LV global longitudinal strain (LVGLS) was averaged from 16 longitudinal LV segments in all 3 layers. LVGLS results were compared with coronary angiography findings in a receiver operating curve (ROC) to determine the cut-off for normal and pathological strain values. The calculated optimal strain value was compared to maximal carotid IMT measurements.

Results

The ROC analysis for strain versus coronary angiography was: area under curve (AUC) = 0.91 (95% CI 0.80 – 1.0), cut-off value for endocardial LVGLS: -16.7%. Further analyses showed that increased carotid IMT correlated with low absolute strain values (p = 0.006) also when adjusted for hypertension, smoking, hyperlipidemia, diabetes and BMI (p = 0.02).

Conclusions

In this study increased carotid IMT values were associated with decreased LV function assessed by strain measurements. These findings support the use of carotid IMT measurements to predict the risk of coronary heart disease.

Association of branched-chain amino acids with carotid intima-media thickness and coronary artery disease risk factors

Background

Recent studies have determined that branched-chain (BCAAs) and aromatic (AAAs) amino acids are strongly correlated with obesity and atherogenic dyslipidemia and are strong predictors of diabetes. However, it is not clear if these amino acids are capable of identifying subjects with coronary artery disease (CAD), particularly with subclinical atherosclerosis who are at risk of developing CAD.

Methods

Four hundred and seventy two Chinese subjects (272 males and 200 females, 42–97 y of age) undergoing physical exams were recruited at random for participation in the cross-sectional study. Serum BCAAs and AAAs were measured using our previously reported isotope dilution liquid chromatography tandem mass spectrometry method. Bilateral B-mode carotid artery images for carotid intima-media thickness (cIMT) were acquired at end diastole and cIMT values more than 0.9 mm were categorized as increased. Correlations of BCAAs with cIMT and other CAD risk factors were analyzed.

Results

BCAAs and AAAs were significantly and positively associated with risk factors of CAD, e.g., cIMT, BMI, waist circumference, blood pressure, fasting blood glucose, TG, apoB, apoB/apoAI ratio, apoCII, apoCIII and hsCRP, and were significantly and negatively associated with HDL-C and apoAI. Stepwise multiple linear regression analysis revealed that age (β = 0.175, P<0.001), log BCAA (β = 0.147, P<0.001) and systolic blood pressure (β = 0.141, P = 0.012) were positively and independently associated with cIMT. In the logistic regression model, the most and only powerful laboratory factor correlated with increased cIMT was BCAA (the odds ratio of the fourth quartile compared to the first quartile was 2.679; P = 0.009).

Conclusion

BCAAs are independently correlated with increased cIMT. This correlation would open a new field of research in the mechanistic understanding and risk assessment of CAD.

Carotid intima-media thickness is associated with incident heart failure among middle-aged whites and blacks: the Atherosclerosis Risk in Communities study

Background

Increased carotid intima‐media thickness (IMT) is associated with subclinical left ventricular myocardial dysfunction, suggesting a possible role of carotid IMT in heart failure (HF) risk determination.

Methods and Results

Mean far wall carotid IMT, measured by B‐mode ultrasound, was available for 13 590 Atherosclerosis Risk in Communities study participants aged 45 to 64 years and free of HF at baseline. HF was defined using ICD‐9 428 and ICD‐10 I‐50 codes from hospitalization records and death certificates. The association between carotid IMT and incident HF was assessed using Cox proportional hazards analysis with models adjusted for demographic variables, major CVD risk factors, and interim CHD. There were 2008 incident HF cases over a median follow‐up of 20.6 years (8.1 cases per 1000 person‐years). Mean IMT was higher in those with HF than in those without (0.81 mm±0.23 versus 0.71 mm±0.17, P<0.001). Unadjusted rate of HF for the fourth compared with the first quartile of IMT was 15.4 versus 3.9 per 1000 person‐years; P<0.001. In multivariable analysis, after adjustment, each standard deviation increase in IMT was associated with incident HF (HR 1.20 [95% CI: 1.16 to 1.25]). After adjustment, the top quartile of IMT was associated with HF (HR 1.60 [95% CI: 1.37 to 1.87]). Results were similar across race and gender groups.

Conclusions

Increasing carotid IMT is associated with incident HF in middle‐aged whites and blacks, beyond risks explained by major CVD risk factors and CHD. This suggests that carotid IMT may be associated with HF through mechanisms different from myocardial ischemia or infarction.

Subclinical Myocardial Disease in Heart Failure Detected by CMR

Noninvasive cardiac imaging plays a central role in the assessment of patients with heart failure at all stages of disease. Moreover, this role can be even more important for individuals with asymptomatic cardiac functional or structural abnormalities-subclinical myocardial disease - because they could have benefits from early interventions before the onset of clinical heart failure. In this sense, cardiac magnetic resonance offers not only precise global cardiac function and cardiac structure, but also more detailed regional function and tissue characterization by recent developing methods. In this section, some of the main methods available for subclinical myocardial disease detection are reviewed in terms of what they can provide and how they can improve heart failure assessment.

The associations between metabolic variables and NT-proBNP are blunted at pathological ranges: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

Under physiological conditions brain natriuretic peptide (BNP) is inversely associated with metabolic risk factors, but under pathological conditions these associations may tend to plateau.

MATERIAL AND METHODS

5597 individuals in the Multi-Ethnic Study of Atherosclerosis (MESA), 45-84years of age, free of overt cardiovascular disease in 2000-02 and then again in 2003-05 participated in this study. Associations between NT-proBNP and BMI, blood lipids, homeostasis model of insulin resistance (HOMA-IR) using linear regression models were adjusted for age, race, sex, BMI, % of energy from saturated fats, intentional exercise, statin use, antihypertensive medication use, diabetes and glomerular filtration rate. The inflection points (IP) at which these associations became nonlinear were determined using linear splines with knots at different levels of NT-proBNP.

RESULTS

Participants with NT-proBNP ≥100pg/mL (29%) tended to be older, on statins and anti-hypertensive medications vs. those with NT-proBNP <100pg/mL. The IP point varies among variables and ranged from 50-120pg/mL. NT-proBNP<IP, associated inversely with BMI, total cholesterol (TC), LDL-C, triglycerides (TG) and HOMA-IR, but positively with HDL-C. A higher proportion of participants with NT-proBNP ≥100pg/mL had subclinical CVD. All associations with NT-proBNP plateaued when NT-proBNP≥IP. Baseline level in NT-proBNP was not associated with 3-year change in BMI, TG, HDL-C or fasting glucose.

CONCLUSIONS

In a large cardiovascular disease-free cohort, NT-proBNP within the lower (physiological) range was inversely associated with TC, LDL-C, TG and insulin resistance with different inflection points, but at higher (pathological) levels these associations were blunted.

Clinical significance of subclinical carotid atherosclerosis and its relationship with echocardiographic parameters in non-diabetic chronic kidney disease patients

Background

Non-diabetic chronic kidney disease (CKD) patients are a heterogeneous group with a variety of prognosis. We investigated the role of subclinical carotid atherosclerosis for the prediction of adverse cardiovascular (CV) outcomes in these patients, and tried to identify clinical and echocardiographic parameters associated with subclinical carotid atherosclerosis.

Methods

As a prospective design, 182 asymptomatic non-diabetic CKD patients underwent carotid ultrasonography and Doppler echocardiography. Carotid atherosclerosis was defined as a carotid intima-media thickness ≥1.0 mm and/or the presence of plaque.

Results

During the mean follow-up period of 28.8 ± 16.1 months, 23 adverse CV events occurred. Patients with carotid atherosclerosis (99, 54.4%) showed significantly higher rates of annual CV events than those without (8.6 vs. 1.5%, p <0.001). Particularly, the presence of carotid plaque was a powerful predictor of adverse CV outcomes (OR 7.80, 95% CI 1.45-45.97). Clinical parameters associated with the presence of subclinical carotid atherosclerosis were old age, previous history of hypertension, increased pulse pressure, and higher high-sensitivity C-reactive protein (hs-CRP) level. By echocardiography, early diastolic mitral annular velocity (E’) and the ratio of early peak transmitral inflow velocity (E) to E’ (E/E’) were closely related with the presence of carotid atherosclerosis. A multivariate analysis showed that age, hs-CRP, and E/E’ were significant determinants of carotid atherosclerosis.

Conclusions

Carotid plaque, even subclinical, was closely associated with a poor prognosis in non-diabetic CKD patients. Increased age, hs-CRP level, and E/E’ ratio may be useful markers suggesting the presence of carotid atherosclerosis in these patients.

Left ventricular function by echocardiography, tissue Doppler imaging, and carotid intima-media thickness in obese adolescents with nonalcoholic fatty liver disease

The aims of this study were to evaluate left ventricular (LV) systolic and diastolic function in obese adolescents with nonalcoholic fatty liver disease (NAFLD) using conventional echocardiography and pulsed-wave tissue Doppler imaging and to investigate the relations between LV function and carotid intima-media thickness (CIMT). LV remodeling, tissue Doppler-derived LV velocities, and cardiovascular risk profiles in obese adolescents with NAFLD were also studied. One hundred eighty obese adolescents and 68 healthy controls were enrolled in the study. LV end-diastolic and end-systolic and left atrial diameters and LV mass were higher in the 2 obese groups compared with controls. By pulsed-wave Doppler echocardiography and pulsed-wave tissue Doppler imaging, the NAFLD group had normal LV systolic function, impaired diastolic function, and altered global systolic and diastolic myocardial performance. In patients with NAFLD, LV mass was positively correlated with homeostasis model assessment of insulin resistance and serum alanine aminotransferase. CIMT was positively correlated with homeostasis model assessment of insulin resistance, alanine aminotransferase, and LV mass. By multiple stepwise regression analysis, alanine aminotransferase (β = 0.124, p = 0.026), homeostasis model assessment of insulin resistance (β = 0.243, p = 0.0001), LV mass (β = 0.874, p = 0.0001) were independent parameters associated with increased CIMT. In conclusion, insulin resistance has a significant independent impact on CIMT and LV remodeling in the absence of diabetes in patients with NAFLD. Pulsed-wave tissue Doppler imaging is suggested to detect LV dysfunction at an earlier stage in obese adolescents with NAFLD for careful monitoring of cardiovascular risk.

Imaging in population science: cardiovascular magnetic resonance in 100,000 participants of UK Biobank - rationale, challenges and approaches

UK Biobank is a prospective cohort study with 500,000 participants aged 40 to 69. Recently an enhanced imaging study received funding. Cardiovascular magnetic resonance (CMR) will be part of a multi-organ, multi-modality imaging visit in 3-4 dedicated UK Biobank imaging centres that will acquire and store imaging data from 100,000 participants (subject to successful piloting). In each of UK Biobank's dedicated bespoke imaging centres, it is proposed that 15-20 participants will undergo a 2 to 3 hour visit per day, seven days a week over a period of 5-6 years. The imaging modalities will include brain MRI at 3 Tesla, CMR and abdominal MRI at 1.5 Tesla, carotid ultrasound and DEXA scans using carefully selected protocols. We reviewed the rationale, challenges and proposed approaches for concise phenotyping using CMR on such a large scale. Here, we discuss the benefits of this imaging study and review existing and planned population based cardiovascular imaging in prospective cohort studies. We will evaluate the CMR protocol, feasibility, process optimisation and costs. Procedures for incidental findings, quality control and data processing and analysis are also presented. As is the case for all other data in the UK Biobank resource, this database of images and related information will be made available through UK Biobank's Access Procedures to researchers (irrespective of their country of origin and whether they are academic or commercial) for health-related research that is in the public interest.

Inter-study reproducibility of cardiovascular magnetic resonance tagging

BACKGROUND

The aim of this study is to determine the test-retest reliability of the measurement of regional myocardial function by cardiovascular magnetic resonance (CMR) tagging using spatial modulation of magnetization.

METHODS

Twenty-five participants underwent CMR tagging twice over 12 ± 7 days. To assess the role of slice orientation on strain measurement, two healthy volunteers had a first exam, followed by image acquisition repeated with slices rotated ±15 degrees out of true short axis, followed by a second exam in the true short axis plane. To assess the role of slice location, two healthy volunteers had whole heart tagging. The harmonic phase (HARP) method was used to analyze the tagged images. Peak midwall circumferential strain (Ecc), radial strain (Err), Lambda 1, Lambda 2, and Angle α were determined in basal, mid and apical slices. LV torsion, systolic and early diastolic circumferential strain and torsion rates were also determined.

RESULTS

LV Ecc and torsion had excellent intra-, interobserver, and inter-study intra-class correlation coefficients (ICC range, 0.7 to 0.9). Err, Lambda 1, Lambda 2 and angle had excellent intra- and interobserver ICC than inter-study ICC. Angle had least inter-study reproducibility. Torsion rates had superior intra-, interobserver, and inter-study reproducibility to strain rates. The measurements of LV Ecc were comparable in all three slices with different short axis orientations (standard deviation of mean Ecc was 0.09, 0.18 and 0.16 at basal, mid and apical slices, respectively). The mean difference in LV Ecc between slices was more pronounced in most of the basal slices compared to the rest of the heart.

CONCLUSIONS

Intraobserver and interobserver reproducibility of all strain and torsion parameters was excellent. Inter-study reproducibility of CMR tagging by SPAMM varied between different parameters as described in the results above and was superior for Ecc and LV torsion. The variation in LV Ecc measurement due to altered slice orientation is negligible compared to the variation due to slice location.

TRIAL REGISTRATION

This trial is registered as NCT00005487 at National Heart, Lung and Blood institute.

Imagining the future of diagnostic imaging

Cardiovascular imaging has become essential to achieving a better understanding of cardiovascular diseases. Due to the advent of new technology and the refinement of existing technologies, imaging's role has extended into the biological, functional, and hemodynamic diagnosis of multiple pathophysiologic processes. Current and future trends in cardiovascular imaging will focus on improving early diagnosis of vascular disease, so as to be able to promote cardiovascular health, and on its development as a useful tool in clinical decision-making. Imaging is also increasingly used to quantify the effect of novel therapies. The rapid development of molecular imaging and fusion imaging techniques improves our understanding of cardiovascular processes from the molecular and cellular points of view and makes it possible to design and test new preventive interventions. The proliferation and integration of imaging techniques in different clinical areas and their role in "translational imaging" plays an important part in the implementation of personalized therapeutic and preventive management strategies for patients with cardiovascular disease.

Relation of carotid artery diameter with cardiac geometry and mechanics in heart failure with preserved ejection fraction

BACKGROUND

Central artery dilation and remodeling are associated with higher heart failure and cardiovascular risks. However, data regarding carotid artery diameter from hypertension to heart failure have remained elusive. We sought to investigate this issue by examining the association between carotid artery diameter and surrogates of ventricular dysfunction.

METHODS AND RESULTS

Two hundred thirteen consecutive patients including 49 with heart failure and preserved ejection fraction (HFpEF), 116 with hypertension, and an additional 48 healthy participants underwent comprehensive echocardiography and tissue Doppler imaging. Ultrasonography of the common carotid arteries was performed for measurement of intima-media thickness and diameter (CCAD). Cardiac mechanics, including LV twist, were assessed by novel speckle-tracking software. A substantial graded enlargement of CCAD was observed across all 3 groups (6.8 ± 0.6, 7.7 ± 0.73, and 8.7 ± 0.95 mm for normal, hypertension, and HFpEF groups, respectively; ANOVA P<0.001) and correlated with serum brain natriuretic peptide level (R(2)=0.31, P<0.001). Multivariable models showed that CCAD was associated with increased LV mass, LV mass-to-volume ratio (β-coefficient=10.9 and 0.11, both P<0.001), reduced LV longitudinal and radial strain (β-coeffficient=0.81 and -3.1, both P<0.05), and twist (β-coefficient=-0.84, P<0.05). CCAD set at 8.07 mm as a cut-off had a 77.6% sensitivity, 82.3% specificity, and area under the receiver operating characteristic curves (AUROC) of 0.86 (95% CI 0.80 to 0.92) in discriminating HFpEF. In addition, CCAD superimposed on myocardial deformation significantly expanded AUROC (for longitudinal strain, from 0.84 to 0.90, P of ΔAUROC=0.02) in heart failure discrimination models.

CONCLUSIONS

Increased carotid artery diameter is associated with worse LV geometry, higher brain natriuretic peptide level, and reduced contractile mechanics in individuals with HFpEF.

Comparison of local sine wave modeling with harmonic phase analysis for the assessment of myocardial strain

PURPOSE

To compare local sine-wave modeling (SinMod) with harmonic phase analysis (HARP), for assessment of left ventricular (LV) circumferential strain (εcc) from tagged cardiovascular magnetic resonance images.

MATERIALS AND METHODS

Mid-ventricular spatial modulation of magnetization was performed in 60 participants (15 each with hypertrophic, dilated or ischemic cardiomyopathy and 15 healthy controls) at 1.5 Tesla. Global and segmental peak transmural εcc were measured using HARP and SinMod. Repeated measurements were performed on 25% of examinations to assess observer variability. Effect of contrast was assessed in 10 additional patients.

RESULTS

SinMod showed a high level of agreement with HARP for global εcc (mean difference -0.02, 95% limits of agreement -6.46 to 6.43%). Agreement was much lower for segmental εcc. Both methods showed excellent observer agreement for global εcc (intraclass correlation coefficient >0.75). Observer agreement for segmental εcc was also excellent with SinMod, but was significantly lower with HARP. Analysis time was significantly shorter using SinMod. Pre- and postcontrast εcc measurements were not significantly different using either technique, although postcontrast measurements showed greater variability with HARP.

CONCLUSION

SinMod and HARP-based measurements of global εcc have a high level of agreement, but segmental agreement is substantially lower. SinMod has generally lower observer variability, is faster and is less affected by contrast, but requires further validation.

Systolic myocardial dysfunction in patients with type 2 diabetes mellitus: identification at MR imaging with cine displacement encoding with stimulated echoes

PURPOSE

To determine if cine displacement encoding with stimulated echoes (DENSE) can help to identify and determine the patterns of subclinical myocardial systolic dysfunction in patients with type 2 diabetes mellitus (DM) when compared with cine DENSE in control patients.

MATERIALS AND METHODS

After obtaining approval from the institutional ethics committee and written informed consent from the patients, 37 patients with type 2 DM without overt heart disease and 23 age-matched control patients were prospectively included in the study. The patients underwent standard cine magnetic resonance (MR) imaging with two-dimensional cine DENSE acquisitions. Circumferential (Ecc) and radial (Err) systolic strains were measured on short-axis views at basal, mid, and apical left ventricular levels. Longitudinal strain (Ell) was measured on four- and two-chamber views. Statistical testing included the intraclass correlation coefficient and multiple linear regression analysis.

RESULTS

The intraobserver intraclass correlation coefficient values were 0.85, 0.95, and 0.90, and the interobserver intraclass correlation coefficient values were 0.79, 0.91 and 0.80 for Ecc, Err, and Ell, respectively. The left ventricular ejection fraction was in the reference range and similar between the groups, and the patients with DM showed a decrease in Ecc (-14.4%±1.6 vs -17.0%±1.6, P<.001), Err (36.2%±10.9 vs 44.4%±9.9, P=.006) and Ell (-12.9%±2.1 vs -15.5%±1.6, P<.001) compared with the control patients. Finally, DM was independently associated with Ecc (P<.001), Err (P=.05) and Ell (P=.01) after adjustment for age, sex, hypertension, body mass index, and left ventricular mass.

CONCLUSION

Cine DENSE, a motion-encoding MR imaging technique for myocardial strain assessment with high spatial resolution, appears to be useful in the identification of subclinical myocardial dysfunction in patients with DM.

Myocardial tagging by cardiovascular magnetic resonance: evolution of techniques--pulse sequences, analysis algorithms, and applications

Cardiovascular magnetic resonance (CMR) tagging has been established as an essential technique for measuring regional myocardial function. It allows quantification of local intramyocardial motion measures, e.g. strain and strain rate. The invention of CMR tagging came in the late eighties, where the technique allowed for the first time for visualizing transmural myocardial movement without having to implant physical markers. This new idea opened the door for a series of developments and improvements that continue up to the present time. Different tagging techniques are currently available that are more extensive, improved, and sophisticated than they were twenty years ago. Each of these techniques has different versions for improved resolution, signal-to-noise ratio (SNR), scan time, anatomical coverage, three-dimensional capability, and image quality. The tagging techniques covered in this article can be broadly divided into two main categories: 1) Basic techniques, which include magnetization saturation, spatial modulation of magnetization (SPAMM), delay alternating with nutations for tailored excitation (DANTE), and complementary SPAMM (CSPAMM); and 2) Advanced techniques, which include harmonic phase (HARP), displacement encoding with stimulated echoes (DENSE), and strain encoding (SENC). Although most of these techniques were developed by separate groups and evolved from different backgrounds, they are in fact closely related to each other, and they can be interpreted from more than one perspective. Some of these techniques even followed parallel paths of developments, as illustrated in the article. As each technique has its own advantages, some efforts have been made to combine different techniques together for improved image quality or composite information acquisition. In this review, different developments in pulse sequences and related image processing techniques are described along with the necessities that led to their invention, which makes this article easy to read and the covered techniques easy to follow. Major studies that applied CMR tagging for studying myocardial mechanics are also summarized. Finally, the current article includes a plethora of ideas and techniques with over 300 references that motivate the reader to think about the future of CMR tagging.