Association of Pro-B-Type Natriuretic Peptide With Cardiac Magnetic Resonance-Measured Global and Regional Cardiac Function and Structure Over 10 Years: The MESA Study.

Background NT-proBNP (N-terminal pro-B-type natriuretic peptide) is widely used to diagnose and manage patients with heart failure. We aimed to investigate associations between NT-proBNP levels and development of global and regional myocardial impairment, dyssynchrony, and risk of developing myocardial scar over time. Methods and Results We included 2416 adults (45-84 years) without baseline clinical cardiovascular disease from MESA (Multi-Ethnic Study of Atherosclerosis). NT-proBNP was assessed at baseline (2000-2002). Cardiac magnetic resonance-measured left ventricular parameters were assessed at baseline and year 10 (2010-2012). Tagged cardiac magnetic resonance and myocardial dyssynchrony were assessed. We used linear and logistic regression models to study the relationships between quartiles of NT-proBNP levels and outcome variables. Left ventricular parameters decreased over time. After 10-year follow-up and adjusting for cardiovascular disease risk factors, people in the highest quartile had significantly greater decline in left ventricular ejection fraction (-1.60%; 95% CI, -2.26 to -0.94; P<0.01) and smaller decline in left ventricular end systolic volume index (-0.47 mL/m2; 95% CI, -1.18 to 0.23; P<0.01) compared with those in the lowest quartile. Individuals in the highest quartile had more severe risk factor adjusted global, mid, and apical regional dyssynchrony compared with those in the lowest, second, and third quartiles (all P-trend<0.05). Compared with the lowest-quartile group, the adjusted odds ratios for having myocardial scar was 1.3 (95% CI, 0.7-2.2) for quartile 2; 1.2 (95% CI, 0.6-2.3) for quartile 3; and 2.7 (95% CI, 1.4-5.5) for quartile 4 (P-trend=0.012) for the total sample. Conclusions Among participants without baseline clinical cardiovascular disease, higher baseline NT-proBNP concentration was significantly associated with subclinical changes in developing myocardial dysfunction, more severe cardiac dyssynchrony, and higher odds of having myocardial scar over a 10-year period independent of traditional cardiovascular disease risk factors.

Association between Obstructive Sleep Apnea and Left Ventricular Structure by Age and Gender: the Multi-Ethnic Study of Atherosclerosis.

STUDY OBJECTIVES: The presence and severity of obstructive sleep apnea (OSA) are associated with impaired left ventricular (LV) structure and function. Our goal was to quantify the associations between LV systolic function and mass with severity of OSA in an ethnically diverse cohort, assessing variations by age and sex. METHODS: We conducted a cross-sectional analysis of data from 1,412 racially/ethnically diverse participants across 6 US communities from the Multi-Ethnic Study of Atherosclerosis who underwent both overnight polysomnography and cardiac magnetic resonance imaging from 2010-2012. We evaluated the association between the obstructive apnea-hypopnea index (AHI) by clinical category (< 5, 5-15, 15-30, 30-50, > 50) and secondary measures of sleep apnea with the outcomes left ventricular (LV) mass adjusted for height, LV mass/volume ratio, and LV ejection fraction. RESULTS: After adjusting for potential confounders and mediators, LV mass was significantly increased with increasing AHI category for subjects age 65 y or younger (ß = 1.84 ± 0.47 g/m, P = 0.0001). The association between the AHI and LV mass appeared stronger in whites and Chinese compared to blacks and Hispanics, although interaction terms were not statistically significant. Additionally, while both LV mass and LV mass/volume ratio were significantly associated with hypoxia, ejection fraction was not associated with any OSA severity index. Comparable associations were observed in men and women. CONCLUSIONS: Independent of confounders, higher levels of AHI are significantly associated with increased LV mass in both men and women younger than 65 y from a community-based cohort.

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.

Regional myocardial functional patterns: Quantitative tagged magnetic resonance imaging in an adult population free of cardiovascular risk factors: The multi-ethnic study of atherosclerosis (MESA).

PURPOSE: To characterize the left ventricular (LV) regional deformation patterns and identify normal values of left ventricular strains from tagged magnetic resonance imaging (MRI) in a population with low-risk-factor (LRF) exposure. MATERIALS AND METHODS: Tagged CMR on three LV short axis slices was performed in participants of the MESA study who were free of cardiovascular disease at baseline. Images were analyzed by the harmonic phase imaging method to obtain: peak torsion, circumferential (Ecc) and radial (Err) strains, and systolic (SRs) and early-diastolic (SRe) strain rates. An LRF group was created from the overall population based on strict exclusion criteria (n = 129) based on risk factors and events observed over a 10-year follow-up. RESULTS: The normative prediction intervals for the averaged peak Ecc (%) and torsion (deg/cm) measures were: in 45-59-year-old women: (-20.8, -13.2) and (2.1, 6.3); 60-84-year-old women: (-20.6, -12.8) and (2.2, 6.9); 45-59-year-old men: (-21.3, -13.5) and (1.9, 5.7); 60-84-year-old men: (-20.5, -12.5) and (1.5, 5.2). In general, African-Americans (Ecc = -15.9, torsion = 3.3) had lower strains as compared to Chinese (Ecc = -17.1, torsion = 3.9), while Caucasians and Hispanics were intermediate and not significantly different. Circumferential shortening increased spatially from the epicardium to the endocardium (-16.9 to -18.2 at the mid-ventricle) and from the base to the apex (-15.1 to -17.5 at the midwall). CONCLUSION: The present study provides reference ranges and deformation patterns of deformation values from a large healthy population free of cardiovascular disease at baseline.

Effect of screening for coronary artery disease using CT angiography on mortality and cardiac events in high-risk patients with diabetes: the FACTOR-64 randomized clinical trial.

IMPORTANCE: Coronary artery disease (CAD) is a major cause of cardiovascular morbidity and mortality in patients with diabetes mellitus, yet CAD often is asymptomatic prior to myocardial infarction (MI) and coronary death. OBJECTIVE: To assess whether routine screening for CAD by coronary computed tomography angiography (CCTA) in patients with type 1 or type 2 diabetes deemed to be at high cardiac risk followed by CCTA-directed therapy would reduce the risk of death and nonfatal coronary outcomes. DESIGN, SETTING, AND PARTICIPANTS: The FACTOR-64 study was a randomized clinical trial in which 900 patients with type 1 or type 2 diabetes of at least 3 to 5 years' duration and without symptoms of CAD were recruited from 45 clinics and practices of a single health system (Intermountain Healthcare, Utah), enrolled at a single-site coordinating center, and randomly assigned to CAD screening with CCTA (n = 452) or to standard national guidelines-based optimal diabetes care (n = 448) (targets: glycated hemoglobin level <7.0%, low-density lipoprotein cholesterol level <100 mg/dL, systolic blood pressure <130 mm Hg). All CCTA imaging was performed at the coordinating center. Standard therapy or aggressive therapy (targets: glycated hemoglobin level <6.0%, low-density lipoprotein cholesterol level <70 mg/dL, high-density lipoprotein cholesterol level >50 mg/dL [women] or >40 mg/dL [men], triglycerides level <150 mg/dL, systolic blood pressure <120 mm Hg), or aggressive therapy with invasive coronary angiography, was recommended based on CCTA findings. Enrollment occurred between July 2007 and May 2013, and follow-up extended to August 2014. MAIN OUTCOMES AND MEASURES: The primary outcome was a composite of all-cause mortality, nonfatal MI, or unstable angina requiring hospitalization; the secondary outcome was ischemic major adverse cardiovascular events (composite of CAD death, nonfatal MI, or unstable angina). RESULTS: At a mean follow-up time of 4.0 (SD, 1.7) years, the primary outcome event rates were not significantly different between the CCTA and the control groups (6.2% [28 events] vs 7.6% [34 events]; hazard ratio, 0.80 [95% CI, 0.49-1.32]; P = .38). The incidence of the composite secondary end point of ischemic major adverse cardiovascular events also did not differ between groups (4.4% [20 events] vs 3.8% [17 events]; hazard ratio, 1.15 [95% CI, 0.60-2.19]; P = .68). CONCLUSIONS AND RELEVANCE: Among asymptomatic patients with type 1 or type 2 diabetes, use of CCTA to screen for CAD did not reduce the composite rate of all-cause mortality, nonfatal MI, or unstable angina requiring hospitalization at 4 years. These findings do not support CCTA screening in this population. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00488033.

Prognostic implications of left ventricular dyssynchrony for major adverse cardiovascular events in asymptomatic women and men: the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Left ventricular (LV) dyssynchrony is related to adverse outcomes in systolic heart failure, but its prognostic importance in asymptomatic population is not known. Our objective was to assess the prognostic implications of LV mechanical dyssynchrony in a large multiethnic population before the occurrence of global LV dysfunction. METHODS AND RESULTS: A total of 1392 participants in the Multi-Ethnic Study of Atherosclerosis (MESA; mean age: 64.7 years; 46% were women) with cardiac magnetic resonance imaging at baseline were followed for a median duration of 8.3 years. Harmonic phase imaging analysis was used to derive systolic circumferential strain. Greater standard deviation of time to peak systolic strain (SD-TPS) indicates greater dyssynchrony. With SD-TPS as a continuous variable, Cox proportional hazards analysis was used to assess hazards ratio after adjusting for demographics, cardiovascular risk factors, LV mass-to-volume ratio, and ejection fraction. Using the 75th percentile of SD-TPS as a cutoff, Kaplan-Meier analysis was performed between 2 categorical groups for each gender. Higher values of dyssynchrony in women predicted major adverse cardiovascular events, defined as myocardial infarction, heart failure, stroke, and death (hazard ratio: 1.01 per 1-ms increment in SD-TPS, P=0.015), hard coronary events (hazard ratio: 1.05 per 1-ms increment in SD-TPS, P=0.026), and cerebrovascular events (hazard ratio: 1.03 per 1-ms increment in SD-TPS, P=0.013). In contrast, dyssynchrony in men was not predictive of events. Kaplan-Meier analyses in women revealed increased event occurrence in the higher dyssynchrony group, but this was not the case in men. CONCLUSIONS: In an asymptomatic cohort, greater LV dyssynchrony determined by cardiac magnetic resonance imaging predicts adverse cardiovascular outcome in women but not in men. CLINICAL TRIAL REGISTRATION URL: http://clinicaltrials.gov. Unique identifier: NCT00005487.

Diagnosis of left ventricular pseudoaneurysm by cardiac CT angiography.

We present a case of a patient with left ventricular pseudoaneurysm which was not noted on transthoracic echocardiography but incidentally detected by CT angiography in preparation of ablation therapy for ventricular tachycardia. The patient underwent successful surgical repair of the pseudoaneurysm. The case illustrates the utility of CT angiography for the diagnosis of this rare, but hazardous condition.

Coronary artery plaque volume and obesity in patients with diabetes: the factor-64 study.

PURPOSE: To determine the relationship between coronary plaque detected with coronary computed tomographic (CT) angiography and clinical parameters and cardiovascular risk factors in asymptomatic patients with diabetes. MATERIALS AND METHODS: All patients signed institutional review board-approved informed consent forms before enrollment. Two hundred twenty-four asymptomatic diabetic patients (121 men; mean patient age, 61.8 years; mean duration of diabetes, 10.4 years) underwent coronary CT angiography. Total coronary artery wall volume in all three vessels was measured by using semiautomated software. The coronary plaque volume index (PVI) was determined by dividing the wall volume by the coronary length. The relationship between the PVI and cardiovascular risk factors was determined with multivariable analysis. RESULTS: The mean PVI (±standard deviation) was 11.2 mm(2) ± 2.7. The mean coronary artery calcium (CAC) score (determined with the Agatston method) was 382; 67% of total plaque was noncalcified. The PVI was related to age (standardized ß = 0.32, P < .001), male sex (standardized ß = 0.36, P < .001), body mass index (BMI) (standardized ß = 0.26, P < .001), and duration of diabetes (standardized ß = 0.14, P = .03). A greater percentage of soft plaque was present in younger individuals with a shorter disease duration (P = .02). The soft plaque percentage was directly related to BMI (P = .002). Patients with discrepancies between CAC score and PVI rank quartiles had a higher percentage of soft and fibrous plaque (18.7% ± 3.3 vs 17.4% ± 3.5 [P = .008] and 52.2% ± 7.2 vs 47.2% ± 8.8 [P < .0001], respectively). CONCLUSION: In asymptomatic diabetic patients, BMI was the primary modifiable risk factor that was associated with total and soft coronary plaque as assessed with coronary CT angiography.

Prognostic value of myocardial circumferential strain for incident heart failure and cardiovascular events in asymptomatic individuals: the Multi-Ethnic Study of Atherosclerosis.

AIMS: Left ventricular (LV) circumferential strain (Ecc) is a sensitive index of regional myocardial function. Currently, no studies have assessed its prognostic value in general population. We sought to investigate whether Ecc has a prognostic value for predicting incident heart failure (HF) and other major cardiovascular events in asymptomatic individuals without a history of previous cardiovascular diseases. METHODS AND RESULTS: We, prospectively, assessed incident HF and atherosclerotic events during a 5.5 ± 1.3-year period in 1768 asymptomatic individuals aged 45-84 (mean age 65 years; 47% female) who underwent tagged magnetic resonance imaging for strain determination. During the follow-up period, 39 (2.2%) participants experienced incident HF and 108 (6.1%) participants had atherosclerotic cardiovascular events. Average of peak Ecc of 12-LV segments (Ecc-global) and mid-slice (Ecc-mid) was -17.0 ± 2.4 and -17.5 ± 2.7%, respectively. Participants with average absolute Ecc-mid lower than -16.9% had a higher cumulative hazard of incident HF (log-rank test, P = 0.001). In cox regression analysis, Ecc-mid predicted incident HF independent of age, diabetes status, hypertension, interim myocardial infarction, LV mass index, and LV ejection fraction (hazard ratio 1.15 per 1%, 95% CI: 1.01-1.31, P = 0.03). This relationship remained significant after adjustment for LV-end-systolic wall stress into covariates. In addition, by adding Ecc-mid to risk factors, LV ejection fraction, and the LV mass index, both the global χ(2) value (76.6 vs. 82.4, P = 0.04) and category-less net-reclassification index (P = 0.01, SE = 0.18, z = 2.53) were augmented for predicting HF. Circumferential strain was also significantly related to the composite atherosclerotic cardiovascular events, but its relationship was attenuated after introducing the LV mass index. CONCLUSION: Circumferential shortening provides robust, independent, and incremental predictive value for incident HF in asymptomatic subjects without any history of previous clinical cardiovascular disease. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Unique identifier: NCT00005487.

Renin Angiotenin Blocker Pre-treatment and Recurrence After Pulmonary Vein Isolation in Patients with Paroxysmal and Persistent Atrial Fibrillation.

Introduction: Pulmonary venous isolation has emerged as an effective method for preventing atrial fibrillation (AF) recurrence. Yet, recurrence is common. Angiotensin-receptor-blockers (ARBs) and angiotensin-converting-enzyme-inhibitors (ACEI) are effective in reducing the extent of myocardial remodeling and fibrosis. Our aim was to study whether pretreatment with ARBs and ACEI was effective in decreasing recurrence after pulmonary vein isolation for patients with AF. Methods: Three hundred and twelve consecutive patients who underwent ablation from 12/2006 until 7/2010 were followed for at least one year. All patients underwent MRI before ablation to assess atrial fibrosis. Data include demographic characteristics, comorbidities, AF type and information regarding treatment with ACEI or ARBs. Results: Most patients were men (62%), mean age was 64. Hypertension (HTN) was present in 60%. Their mean ejection fraction was 60%. There were 104 patients (33.3%) treated with ACEI, and 13.5 % were treated with ARBs prior to ablation. Ninety seven patients (31.1%) had AF recurrence. AF type was a significant predictor for recurrence (recurrence with paroxysmal, persistent and long-standing persistent: 23.75, 37.3 and 60%, respectively, p=0.005). The most important factor predicting recurrence was increased pre-ablation atrial fibrosis (p<0.0001). Recurrence was more frequent in patients treated with ACEI (40.4% vs 26.4% untreated patients, p=0.012). In the ARB treated group, 38.1% vs 30.0% untreated experienced recurrence (p=0.3). After multivariable adjustment for demographics, risk factors and atrial fibrosis, treatment with ACEI was associated with increased rate of recurrence in patients with persistent AF (hazard ratio: 2.6, p=0.003). There was no significant relation between ACEI pretreatment and recurrence in patients with paroxysmal AF (HR- 0.83, p=0.7), or between ARB pre-treatment and recurrence in patients with paroxysmal as well as persistent AF (p=0.2 and 0.53, respectively). Conclusions: Pretreatment with ACEI or ARBs is not associated with reduced recurrence rate in patients with paroxysmal or persistent AF undergoing ablation.

The potential contribution of ranolazine to Torsade de Pointe.

Ranolazine is a novel anti-anginal agent acting through pharmacologic mechanism of inhibition of the late phase of the inward sodium current. In addition, it is a potent inhibitor of rapid delayed rectifier potassium currents, leading to prolongation of the QT interval. However, ranolazine has not yet described to be associated with Torsade de Pointes despite its QT-prolonging effect. In this case report, we describe a patient on ranolazine who developed Torsade de Pointes and discuss about the potential contribution of ranolazine to the development of Torsade de Pointes.

The expanding role of computed tomography in the assessment of coronary artery disease and cardiac anatomy.

There are increasing options for noninvasive tests to assess patients with chest pain syndromes or risk factors for atherosclerosis. Choosing the optimal test for an individual patient can be challenging. This review focuses on the expanding role of cardiac computed tomography (CT) and the rationale for its use in different patient groups. It also discusses which patients are best suited for cardiac CT and the necessary patient preparation.

Usefulness of radial strain mapping by multidetector computer tomography to quantify regional myocardial function in patients with healed myocardial infarction.

We introduce and evaluate strain mapping by multidetector computer tomography as a new noninvasive method for assessment of myocardial function. In patients (n = 16) with healed myocardial infarction, peak systolic radial strain was measured by automated pixel pattern matching analysis of multiple left ventricular 64-slice multidetector computer tomographic short-axis recordings. For comparison, radial strain and myocardial infarct extent were measured by tagged magnetic resonance imaging (MRI) and late enhancement MRI, respectively. In a linear mixed model analysis, myocardial infarct extent was a strong predictor of segmental strain by multidetector computer tomography (beta = -0.44, p <0.0001). Strain was significantly different among noninfarcted (0%), nontransmurally infarcted (0% to 50%), and transmurally infarcted (>50%) segments (p <0.001) and between infarcted and noninfarcted border zone segments (p <0.001). There was a close relation between strain by multidetector computer tomography and by tagged MRI (mean difference -7.4 +/- 11.7%, r = 0.68, p <0.0001). Mean time-to-peak systolic strain was 324 +/- 42 ms by multidetector computer tomography and 335 +/- 56 ms by tagged MRI (mean difference 11 +/- 40 ms). In conclusion, to our knowledge this is the first study to demonstrate that regional myocardial function can be quantified by multidetector computer tomographic imaging, indicating that assessment of radial strain by multidetector computer tomography might be a useful tool in the evaluation of patients with cardiovascular diseases.

Relationship of interleukin-6 with regional and global left-ventricular function in asymptomatic individuals without clinical cardiovascular disease: insights from the Multi-Ethnic Study of Atherosclerosis.

AIMS: We sought to examine the relationship between circulating interleukin-6 (IL-6) level and regional left-ventricular (LV) function among apparently healthy individuals free of cardiovascular disease. METHODS AND RESULTS: Using magnetic resonance myocardial tagging, we determined peak systolic circumferential strain (Ecc) as a measure of regional systolic function in 894 asymptomatic participants in the Multi-Ethnic Study of Atherosclerosis. Ecc was analysed by harmonic phase imaging separately in the LV anterior wall, septum, lateral wall, and inferior wall. Global Ecc was calculated as the average of Ecc in all myocardial segments. We performed multivariable linear regression to evaluate the independent associations between log IL-6 and Ecc, after adjusting for demographic features, cardiovascular risk factors, and markers of subclinical atherosclerosis. The inverse relationships between IL-6 and absolute Ecc were similar in both genders. In multivariable analysis, higher IL-6 level was independently associated with reduced systolic function (less negative Ecc) in the septum [regression coefficient = 1.03 per unit higher log IL-6, 95% confidence interval (CI) 0.26-1.79, P = 0.008] and inferior wall (regression coefficient = 1.65, 95% CI 0.74-2.56, P < 0.001), but not in the anterior wall (P = 0.27) or lateral wall (P = 0.52). Overall, there was an independent inverse association between IL-6 and global Ecc (regression coefficient = 0.94, 95% CI 0.37-1.51, P = 0.001). Compared with C-reactive protein, higher IL-6 level demonstrates a stronger independent association with reduced regional systolic function. CONCLUSION: In asymptomatic men and women without documented cardiovascular disease, there is a strong, independent, inverse relationship between IL-6 and regional LV systolic function. These findings suggest that IL-6 may underlie the pathogenetic link between inflammation, LV dysfunction and incipient heart failure. The observed variable relationships between IL-6 and systolic function across different LV regions warrant further investigations.

Relationship between baseline coronary calcium score and demonstration of coronary artery stenoses during follow-up MESA (Multi-Ethnic Study of Atherosclerosis).

OBJECTIVES: The MESA (Multi-Ethnic Study of Atherosclerosis) is a population-based study of 6,814 men and women. We sought to analyze the relationship between the extent of coronary artery calcium (CAC) at baseline and the severity of coronary stenoses in clinically indicated coronary angiography studies during follow-up. BACKGROUND: CAC is an established predictor of major cardiovascular events. Yet, the relationship between CAC and the distribution and severity of coronary artery stenoses has not been widely explored. METHODS: All MESA participants underwent noncontrast enhanced cardiac computed tomography during enrollment to determine baseline CAC. We analyzed 175 consecutive angiography reports from participants who underwent coronary catheterization for clinical indications during a median follow-up period of 18 months. The relationship between baseline CAC and the severity of coronary stenosis detected in coronary angiographies was determined. RESULTS: Baseline Agatston score was 0 in only 7 of 175 (4%) MESA participants who underwent invasive angiography during follow-up. When coronary arteries were studied separately, 13% to 18% of coronary arteries with >or=75% stenosis had 0 calcium mass scores at baseline. There was close association between baseline calcium mass score and the severity of stenosis in each of the coronary arteries (test for trend, p < 0.001). For example, mean calcium mass scores for <50%, 50% to 74%, and >or=75% stenosis in the left anterior descending coronary artery were 105.1 mg, 157.2 mg, and 302.2 mg, respectively (p < 0.001). Finally, there was a direct relationship between the total Agatston Score at baseline and the number of diseased vessels (test for trend, p < 0.001). CONCLUSIONS: The majority of patients with clinically indicated coronary angiography during follow-up had detectable coronary calcification at baseline. Although there is a significant relationship between the extent of calcification and mean degree of stenosis in individual coronary vessels, 16% of the coronary arteries with significant stenoses had no calcification at baseline.

Age, increased left ventricular mass, and lower regional myocardial perfusion are related to greater extent of myocardial dyssynchrony in asymptomatic individuals: the multi-ethnic study of atherosclerosis.

BACKGROUND: Age and left ventricular (LV) hypertrophy are risk factors for the development of LV dysfunction and congestive heart failure. Our goal was to study the relationships of LV mass and age with myocardial dyssynchrony among asymptomatic participants of the Multi-Ethnic Study of Atherosclerosis. METHODS AND RESULTS: A total of 1100 individuals underwent tagged magnetic resonance imaging. Regional LV function was analyzed with the use of harmonic phase imaging. Time to peak systolic circumferential strain and strain rate were measured in 12 segments, and myocardial dyssynchrony was expressed as the SD of time to peak strain and strain rate. Relationships of age, LV mass, and myocardial perfusion with timing of strain, strain rate, and dyssynchrony were studied. There was a positive relationship between age and time to peak strain before (regression coefficient=0.37 ms/year of age; 95% confidence interval, 0.05 to 0.70; P=0.025) and after adjustment for demographic characteristics and risk factors (P=0.007). Positive associations between age and SD of time to peak strain (regression coefficient=0.33 ms/year of age; P=0.002) and SD of time to peak systolic strain rate were documented (P=0.045). Importantly, we found that LV mass index is directly related to time to peak strain (P<0.001), time to peak strain rate, and the SD of time to strain rate (P=0.001 for all). Finally, decreased myocardial perfusion at rest was associated with delayed contraction and increased extent of dyssynchrony. CONCLUSIONS: In asymptomatic individuals, age, increased LV mass, and decreased myocardial perfusion are related to delayed myocardial contraction and greater extent of dyssynchrony. Increased dyssynchrony may mediate the association of myocardial dysfunction with age and LV hypertrophy.

Diastolic suction is impaired by bed rest: MRI tagging studies of diastolic untwisting.

Bed rest deconditioning leads to physiological cardiac atrophy, which may compromise left ventricular (LV) filling during orthostatic stress by reducing diastolic untwisting and suction. To test this hypothesis, myocardial-tagged magnetic resonance imaging (MRI) was performed, and maximal untwisting rates of the endocardium, midwall, and epicardium were calculated by Harmonic Phase Analysis (HARP) before and after -6 degrees head-down tilt bed rest for 18 days with (n = 14) and without exercise training (n = 10). LV mass and LV end-diastolic volume were measured using cine MRI. Exercise subjects cycled on a supine ergometer for 30 min, three times per day at 75% maximal heart rate (HR). After sedentary bed rest, there was a significant reduction in maximal untwisting rates of the midwall (-46.8 +/- 14.3 to -35.4 +/- 12.4 degrees /s; P = 0.04) where untwisting is most reliably measured, and to a lesser degree of certainty in the endocardium (-50.3 +/- 13.8 to -40.1 +/- 18.5 degrees /s; P = 0.09); the epicardium was unchanged. In contrast, when exercise was performed in bed, untwisting rates were enhanced at the endocardium (-48.4 +/- 20.8 to -72.3 +/- 22.3 degrees /ms; P = 0.05) and midwall (-39.2 +/- 12.2 to -59.0 +/- 19.6 degrees /s; P = 0.03). The differential response was significant between groups at the endocardium (interaction P = 0.02) and the midwall (interaction P = 0.004). LV mass decreased in the sedentary group (156.4 +/- 30.3 to 149.5 +/- 27.9 g; P = 0.07), but it increased slightly in the exercise-trained subjects (156.4 +/- 34.3 to 162.3 +/- 40.5 g; P = 0.16); (interaction P = 0.03). We conclude that diastolic untwisting is impaired following sedentary bed rest. However, exercise training in bed can prevent the physiological cardiac remodeling associated with bed rest and preserve or even enhance diastolic suction.

Arterial stiffness is associated with regional ventricular systolic and diastolic dysfunction: the Multi-Ethnic Study of Atherosclerosis.

OBJECTIVE: The pathophysiology of left ventricular (LV) dysfunction, particularly in the setting of a preserved ejection fraction (EF), remains unclear. Few studies have investigated the relationship between arterial compliance and LV function in humans, and none used cardiovascular MRI. METHODS AND RESULTS: We sought to determine whether arterial compliance is related to regional myocardial function among participants of the Multi-Ethnic Study of Atherosclerosis (MESA). Arterial compliance was assessed using carotid ultrasound measurements to calculate the distensibility coefficient (DC) and Young's modulus (YM). Circumferential systolic (SR(S)) and diastolic (SR(E)) strain rates were calculated by harmonic phase (HARP) from tagged MRI. Associations between arterial compliance and indices of ventricular function were adjusted for cardiovascular risk factors. We found a significant association between arterial compliance and SR(S) in all myocardial regions (P<0.05); arterial compliance was also associated with SR(E) in the lateral and septal wall regions (P<0.05). Multiple linear regression analyses demonstrated a direct linear relationship between the carotid artery DC and SR(S) across all LV segments and slices, even after adjustment for cardiovascular risk factors and LV mass. In regression analyses, a significant relationship between arterial compliance and SR(E) in the septal and antero-apical walls was also found and remained significant after multivariable adjustment. CONCLUSIONS: Arterial stiffness is associated with early and asymptomatic impairment of systolic as well as diastolic myocardial function. Further studies are needed to elucidate role of vascular compliance in the development of ventricular dysfunction and failure.

The influence of left ventricular size and global function on regional myocardial contraction and relaxation in an adult population free of cardiovascular disease: a tagged CMR study of the MESA cohort.

The purpose of this study is to evaluate the relationship between LV structure and function with regional myocardial function in participants of the Multi-Ethnic Study of Atherosclerosis, which is a prospective study including 4 ethnic groups free from clinical cardiovascular disease. Peak systolic strain (Ecc) and regional strain rates (SRS and SRE) were calculated by harmonic phase from tagged CMR of 1100 participants. The relationships of ejection fraction (EF), end-systolic volume (ESV) and end-diastolic volume (EDV) with Ecc and strain rate were studied before and after adjustment for cardiovascular risk factors. Direct linear relationships between EF and regional systolic and diastolic functions (Ecc, SRS and SRE) were present in almost all of the regions (p < 0.05, i.e., greater EF, greater Ecc, SRS and SRE). LVESV demonstrated a negative relationship with Ecc and SRS (i.e., greater ESV, lower systolic function, indexed by Ecc and SRS) in all regions (p < or = 0.05). LVEDV was inversely related to systolic function, indexed by SR(S) (p < 0.05) in all regions. In conclusion, LVEF is directly related to systolic myocardial function, indexed as the absolute magnitude of systolic strain and strain rate. In addition, left ventricular size, indexed as end-diastolic and end-systolic volumes are inversely related to absolute systolic myocardial strain rate (SRS). These results are crucial to the interpretation of strain alterations induced by left ventricular remodeling in early heart failure.