João A C Lima

Johns Hopkins University, Baltimore, Maryland, United States

Are you João A C Lima?

Claim your profile

Publications (481)3327.28 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Prognostic significance of left atrial (LA) function in patients with atrial fibrillation (AF) is poorly defined. Objective: To examine the association of LA function measured with cardiac magnetic resonance (CMR) feature-tracking and AF recurrence following catheter ablation. Methods: 121 AF patients (72% paroxysmal, mean age 59±10 years) were enrolled. Baseline LA function was measured by calculating passive, active and total emptying fractions (LAEF) and analysis of global longitudinal strain and strain rates. Patients were followed-up for recurrence of AF or atrial tachycardia (AT). Hazard ratios for recurrence were calculated using Cox proportional models adjusted for potential clinical confounders, type of AF, left ventricular ejection fraction, AF duration, LA volume and late gadolinium enhancement (LGE). Results: During a mean follow up of 18± 9 months, 52 patients (43%) experienced recurrent AF/AT. Patients with recurrent AF/AT had higher baseline LA volume index and lower LA passive, and total LAEF (P<0.05 for all). The baseline peak LA strain and strain rates in all phases of LA function were lower in the AF/AT recurrence group (p<0.01 for all). In multivariable analysis total LAEF, peak LA strain, and systolic and late diastolic starin rates were associated with recurrence. Both peak LA strain or total LAEF improved prediction of recurrent AT/AF compared to the baseline clinical model including LA LGE (C statistic 0.82 vs. 0.77,p=<0.05 for both total LAEF and peak LA strain). Conclusions: LA reservoir function was independently associated with recurrent AF/AT after PVI and can additionally improve risk stratification in patients undergoing PVI.
    No preview · Article · Jan 2016 · Heart rhythm: the official journal of the Heart Rhythm Society
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background: Total atherosclerotic plaque burden assessment by CT angiography (CTA) is a promising tool for diagnosis and prognosis of coronary artery disease (CAD) but its validation is restricted to small clinical studies. We tested the feasibility of semi-automatically derived coronary atheroma burden assessment for identifying patients with hemodynamically significant CAD in a large cohort of patients with heterogenous characteristics. Methods: This study focused on the CTA component of the CORE320 study population. A semi-automated contour detection algorithm quantified total coronary atheroma volume defined as the difference between vessel and lumen volume. Percent atheroma volume (PAV = [total atheroma volume/total vessel volume] × 100) was the primary metric for assessment (n = 374). The area under the receiver operating characteristic curve (AUC) determined the diagnostic accuracy for identifying patients with hemodynamically significant CAD defined as ≥50% stenosis by quantitative coronary angiography and associated myocardial perfusion abnormality by SPECT. Results: Of 374 patients, 139 (37%) had hemodynamically significant CAD. The AUC for PAV was 0.78 (95% confidence interval [CI] 0.73-0.83) compared with 0.84 [0.79-0.88] by standard expert CTA interpretation (p = 0.02). Accuracy for both CTA (0.91 [0.87, 0.96]) and PAV (0.86 [0.81-0.91]) increased after excluding patients with history of CAD (p < 0.01 for both). Bland-Altman analysis revealed good agreement between two observers (bias of 280.2 mm(3) [161.8, 398.7]). Conclusions: A semi-automatically derived index of total coronary atheroma volume yields good accuracy for identifying patients with hemodynamically significant CAD, though marginally inferior to CTA expert reading. These results convey promise for rapid, reliable evaluation of clinically relevant CAD.
    Full-text · Article · Jan 2016 · Journal of cardiovascular computed tomography
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Aims: Longitudinal determinants of aortic stiffness (AS) measured by magnetic resonance imaging (MRI) have not been assessed in a large community-based population. Our aim was to examine the determinants of change in thoracic AS over 10 years of follow-up in a multi-ethnic population of individuals 45 years of age and older measured by MRI. Methods and results: We studied 1160 participants (mean age = 60 ± 9 years at baseline, 45% male) with aortic MRI at both the MESA Year 0 and Year 10 examinations. Ascending and descending aorta distensibility (AAD/DAD) and aortic arch pulse-wave velocity (PWV) were measured using MRI. Determinants of the change in AS parameters over 10 years were assessed using linear regression adjusted for baseline values, demographic variables, baseline risk factors and change in risk factors, and chronic risk exposure. AAD and DAD decreased slightly (5% decrease in median for AAD: 1.33-1.26 mmHg(-1) · 10(-3), P = 0.008; 5% decrease in median for DAD: 1.73-1.64 mmHg(-1) · 10(-3), P < 0.001), and PWV increased over 10 years (18% increase in median: 6.8-8.0 m/s P < 0.001). Baseline age was related to a reduction in AAD and DAD and an increase in PWV throughout the follow-up period. Baseline and change in mean blood pressure and continued smoking were associated with a reduction in AAD and an increase in PWV. Furthermore, baseline heart rate was also related to a reduction in AAD and DAD. Blood pressure normalization was related to less aortic stiffening throughout the follow-up period. Conclusions: In our longitudinal, community-based cohort study of adult individuals aged 45 years or greater, greater mean blood pressure and a history of smoking history were associated with increased aortic stiffening over 10 years as assessed by MRI.
    Full-text · Article · Jan 2016 · European Heart Journal Cardiovascular Imaging
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose: To propose long axis strain (LAS), a novel index of global left ventricle (LV) function, as a sensitive and powerful predictor of hard cardiovascular events and heart failure in the Multi-Ethnic Study of Atherosclerosis (MESA). Materials and methods: Strain is an index of relative myocardial deformation, and enables normalization for differences in heart size. Measurement of strain conventionally requires dedicated software and protocols for image acquisition. LAS, however, can be analyzed using a caliper tool from conventional LV long axis magnetic resonance imaging (MRI) cine loops, reflecting the average myocardial contraction in the longitudinal direction. In all, 1651 participants (53% men) of the MESA study, without a history of myocardial infarction or heart failure, were assessed using conventional cine MR images. LV lengths were assessed at end-diastole (EDL ) and end-systole (ESL ), and LAS was calculated as 100*(EDL -ESL )/EDL . Participants were followed for 6.8 ± 1.8 years for a composite endpoint of congestive heart failure or hard cardiovascular events, and the predictive ability of LAS was tested, unadjusted and adjusted for established cardiovascular risk factors. Results: A total of 114 events were observed. Mean LAS was 11.7 ± 2.5% and 10.0 ± 2.7% in participants without and with events, respectively (P < 0.001). Increased LAS reduced the hazard ratio to 0.75 for univariate, and 0.88 for multivariate assessments, respectively (both P < 0.001). Conclusion: Assessment of long axis LV deformation by LAS is feasible and reproducible. Moreover, LAS predicts hard cardiovascular events and congestive heart failure in a multi-ethnic population without overt cardiovascular disease at inclusion. J. Magn. Reson. Imaging 2016.
    No preview · Article · Jan 2016 · Journal of Magnetic Resonance Imaging
  • [Show abstract] [Hide abstract]
    ABSTRACT: Rationale: Recent studies have focused on the role of female sex and estradiol (E2) in pulmonary arterial hypertension (PAH), but it is not known whether sex hormones are risk factors for PAH in men. Objectives: We performed a case-control study to determine whether hormone levels (E2, dehydroepiandrosterone-sulfate [DHEA-S], and testosterone) are associated with PAH in men. Methods: Plasma sex hormone levels in men with idiopathic, heritable, or connective tissue disease-associated PAH were compared to those from age- and body mass index-matched men without clinical cardiovascular disease. Measurements and main results: There were 23 cases with PAH (70% had idiopathic PAH, 65% were functional class III/IV) and 67 controls. Higher E2 and E2:testosterone levels were associated with the risk of PAH (OR per 1 ln[E2:testosterone] = 6.0, 95% CI 2.2 - 16.4, p = 0.001) while higher levels of DHEA-S were associated with a reduced risk (OR per 1 ln[DHEA-S] = 0.1, 95% CI 0.0 - 0.3, p = 0.001). E2 and DHEA-S levels were strong predictors of case status (c-statistic for both 0.82) but testosterone was not (c-statistic 0.53). Higher levels of E2 were associated with shorter six-minute walk distances (p = 0.03) whereas higher levels of DHEA-S were associated with lower right atrial pressure (p = 0.02) and pulmonary vascular resistance (p = 0.01) in men with PAH. Conclusions: Higher levels of E2 and lower levels of DHEA-S were associated with PAH in men. Sex-based differences in sex hormone processing and signaling may contribute to unique phenotypes in pulmonary vascular disease.
    No preview · Article · Dec 2015 · American Journal of Respiratory and Critical Care Medicine
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sex hormones are linked to right ventricular (RV) function, but the relationship between genetic variation in these pathways and RV function is unknown.We performed a cross-sectional study of 2761 genotyped adults without cardiovascular disease. The relationships between RV measures and single nucleotide polymorphisms (SNPs) in 10 candidate genes were assessed. Urinary oestradiol (E2) metabolites produced by cytochrome P4501B1 (CYP1B1) and serum testosterone were measured in women and men respectively. In African-American (AA) women, the CYP1B1 SNP rs162561 was associated with RV ejection fraction (RVEF), such that each copy of the A allele was associated with a 2.0% increase in RVEF. Haplotype analysis revealed associations with RVEF in AA (global p<7.2×10(-6)) and white (global p=0.05) women. In white subjects, higher E2 metabolite levels were associated with significantly higher RVEF. In men, androgen receptors SNPs (rs1337080; rs5918764) were significantly associated with all RV measures and modified the relationship between testosterone and RVEF.Genetic variation in E2 metabolism and androgen signalling was associated with RV morphology in a sex-specific manner. The CYP1B1 SNP identified is in tight linkage disequilibrium with SNPs associated with pulmonary hypertension and oncogenesis, suggesting these pathways may underpin sexual dimorphism in RV failure.
    No preview · Article · Dec 2015 · European Respiratory Journal
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dietary quality affects cardiometabolic risk, yet its pathways of influence on regional adipose tissue depots involved in metabolic and diabetes risk are not well established. We aimed to investigate the relationship between dietary quality and regional adiposity.
    No preview · Article · Dec 2015

  • No preview · Article · Dec 2015 · Journal of the American College of Cardiology
  • [Show abstract] [Hide abstract]
    ABSTRACT: Importance Although cardiorespiratory fitness (CRF) is prognostic in older adults, the effect of CRF during early adulthood on long-term cardiovascular structure, function, and prognosis is less clear.Objective To examine whether CRF in young adults is associated with long-term clinical outcome and subclinical cardiovascular disease (CVD).Design, Setting, and Participants Prospective study of 4872 US adults aged 18 to 30 years who underwent treadmill exercise testing at a baseline study visit from March 25, 1985, to June 7, 1986, and 2472 individuals who underwent a second treadmill test 7 years later. Median follow-up was 26.9 years, with assessment of obesity, left ventricular mass and strain, coronary artery calcification (CAC), and vital status and incident CVD. Follow-up was complete on August 31, 2011, and data were analyzed from recruitment through the end of follow-up.Main Outcomes and Measures The presence of CAC was assessed by computed tomography at years 15 (2000-2001), 20 (2005-2006), and 25 (2010-2011), and left ventricular mass was assessed at years 5 (1990-1991) and 25 (with global longitudinal strain). Incident CVD and all-cause mortality were adjudicated.Results Of the 4872 individuals, 273 (5.6%) died and 193 (4.0%) experienced CVD events during follow-up. After comprehensive adjustment, each additional minute of baseline exercise test duration was associated with a 15% lower hazard of death (hazard ratio [HR], 0.85; 95% CI, 0.80-0.91; P < .001) and a 12% lower hazard of CVD (HR, 0.88; 95% CI, 0.81-0.96; P = .002). Higher levels of baseline CRF were associated with significantly lower left ventricular mass index (β = −0.24; 95% CI, −0.45 to −0.03; P = .02) and significantly better lobal longitudinal strain (β = −0.09; 95% CI, −0.14 to −0.05; P < .001) at year 25. Fitness was not associated with CAC. A 1-minute reduction in fitness by year 7 was associated with 21% and 20% increased hazards of death (HR, 1.21; 95% CI, 1.07-1.37; P = .002) and CVD (HR, 1.20; 95% CI, 1.06-1.37; P = .006), respectively, along with a more impaired strain (β = 0.15; 95% CI, 0.08-0.23; P < .001). No association between change in fitness and CAC was found.Conclusions and Relevance Higher levels of fitness at baseline and improvement in fitness early in adulthood are favorably associated with lower risks for CVD and mortality. Fitness and changes in fitness are associated with myocardial hypertrophy and dysfunction but not CAC. Regular efforts to ascertain and improve CRF in young adulthood may play a critical role in promoting cardiovascular health and interrupting early CVD pathogenesis.
    No preview · Article · Nov 2015 · JAMA Internal Medicine
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background Although adverse left ventricular shape changes (remodeling) after myocardial infarction (MI) are predictive of morbidity and mortality, current clinical assessment is limited to simple mass and volume measures, or dimension ratios such as length to width ratio. We hypothesized that information maximizing component analysis (IMCA), a supervised feature extraction method, can provide more efficient and sensitive indices of overall remodeling. Methods IMCA was compared to linear discriminant analysis (LDA), both supervised methods, to extract the most discriminatory global shape changes associated with remodeling after MI. Finite element shape models from 300 patients with myocardial infarction from the DETERMINE study (age 31–86, mean age 63, 20 % women) were compared with 1991 asymptomatic cases from the MESA study (age 44–84, mean age 62, 52 % women) available from the Cardiac Atlas Project. IMCA and LDA were each used to identify a single mode of global remodeling best discriminating the two groups. Logistic regression was employed to determine the association between the remodeling index and MI. Goodness-of-fit results were compared against a baseline logistic model comprising standard clinical indices. Results A single IMCA mode simultaneously describing end-diastolic and end-systolic shapes achieved best results (lowest Deviance, Akaike information criterion and Bayesian information criterion, and the largest area under the receiver-operating-characteristic curve). This mode provided a continuous scale where remodeling can be quantified and visualized, showing that MI patients tend to present larger size and more spherical shape, more bulging of the apex, and thinner wall thickness. Conclusions IMCA enables better characterization of global remodeling than LDA, and can be used to quantify progression of disease and the effect of treatment. These data and results are available from the Cardiac Atlas Project (
    Full-text · Article · Nov 2015 · Journal of Translational Medicine
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objectives: The purpose of this study was to develop a quantitative method for myocardial blood flow (MBF) measurement using contrast-enhanced multidetector computed tomography (MDCT) images with bolus tracking and helical scanning. Materials and Methods: Nine canine models of left anterior descending artery stenosis were prepared and underwent MDCT perfusion imaging during adenosine infusion to study a wide range of flow parameters. Neutron-activated microspheres were injected to document MBF during adenosine infusion. Six animals underwent dynamic MDCT perfusion imaging, and K1 and k2 (which represent the first-order transfer constants from left ventricular blood to myocardium and from myocardium to the vascular system, respectively) were measured using a two-compartment model. The results were compared against microsphere MBF measurements, and the extraction fraction (E) of contrast agent and the mean value of K1/k2 were calculated. Six animals then underwent helical CT perfusion imaging, and neutron-activated microspheres were injected to document MBF during adenosine infusion. For each animal, based on E, K1/k2, time-registered helical CT myocardial data, and arterial input function data, tables of myocardial CT values versus MBF were simulated for various MBF values to create look-up tables from the myocardial CT value to MBF. The CT-derived MBF values were compared against the microsphere MBF measurements. Results: A strong linear correlation was observed between the MDCT-derived MBF and the microsphere MBF (y = 1.065x – 0.616, R2 = 0.838). Conclusions: Regional MBF can be measured accurately using a combination of bolus tracking and time-registered helical CT data from contrast-enhanced MDCT scanning during adenosine stress.
    Full-text · Article · Oct 2015
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose To evaluate age-related left ventricular (LV) remodeling during longitudinal observation of a large cohort of asymptomatic individuals who were free of clinical cardiovascular disease at baseline. Materials and Methods The applicable institutional review boards approved this study, and all participants gave informed consent. Cardiac magnetic resonance (MR) imaging was used to identify longitudinal changes in LV structure and function in 2935 participants who underwent baseline and follow-up cardiac MR imaging in the Multi-Ethnic Study of Atherosclerosis. Participants were free of clinical cardiovascular disease at baseline. Participants who experienced an incident coronary heart disease event were excluded. Data were analyzed with multivariable mixed-effects regression models in which the outcome was cardiac MR imaging measurement, and the covariates included follow-up time and cardiac risk factors. Results Participants were aged 54-94 years at follow-up, and 53% of the participants were women. Median time between baseline and follow-up cardiac MR imaging was 9.4 years. Over this period, LV mass increased in men and decreased slightly in women (8.0 and -1.6 g per decade, respectively; P < .001). In both men and women, LV end-diastolic volume decreased (-9.8 and -13.3 mL per decade, respectively; P < .001), stroke volume decreased (-8.8 and -8.6 mL per decade, respectively; P < .001), and mass-to-volume ratio increased (0.14 and 0.11 g/mL per decade, respectively; P < .001). Change in LV mass was positively associated with systolic blood pressure and body mass index and negatively associated with treated hypertension and high-density lipoprotein cholesterol level. In men, the longitudinal LV mass increase was in contrast to a cross-sectional pattern of LV mass decrease. Conclusion As patients age, the LV responds differently in its mass and volume between men and women, although both men and women experience increased concentric LV remodeling with age. In men, the opposition of longitudinal and cross-sectional changes in LV mass highlights the importance of longitudinal study. (©) RSNA, 2015 Online supplemental material is available for this article.
    No preview · Article · Oct 2015 · Radiology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Establishing the diagnosis of coronary artery disease (CAD) in symptomatic patients allows appropriately allocating preventative measures. Single-photon emission computed tomography (CT)-acquired myocardial perfusion imaging (SPECT-MPI) is frequently used for the evaluation of CAD, but coronary CT angiography (CTA) has emerged as a valid alternative. Methods and Results-We compared the accuracy of SPECT-MPI and CTA for the diagnosis of CAD in 391 symptomatic patients who were prospectively enrolled in a multicenter study after clinical referral for cardiac catheterization. The area under the receiver operating characteristic curve was used to evaluate the diagnostic accuracy of CTA and SPECT-MPI for identifying patients with CAD defined as the presence of ≥1 coronary artery with ≥50% lumen stenosis by quantitative coronary angiography. Sensitivity to identify patients with CAD was greater for CTA than SPECT-MPI (0.92 versus 0.62, respectively; P<0.001), resulting in greater overall accuracy (area under the receiver operating characteristic curve, 0.91 [95% confidence interval, 0.88-0.94] versus 0.69 [0.64-0.74]; P<0.001). Results were similar in patients without previous history of CAD (area under the receiver operating characteristic curve, 0.92 [0.89-0.96] versus 0.67 [0.61-0.73]; P<0.001) and also for the secondary end points of ≥70% stenosis and multivessel disease, as well as subgroups, except for patients with a calcium score of ≥400 and those with high-risk anatomy in whom the overall accuracy was similar because CTA's superior sensitivity was offset by lower specificity in these settings. Radiation doses were 3.9 mSv for CTA and 9.8 for SPECT-MPI (P<0.001). Conclusions-CTA is more accurate than SPECT-MPI for the diagnosis of CAD as defined by conventional angiography and may be underused for this purpose in symptomatic patients.
    Full-text · Article · Oct 2015 · Circulation Cardiovascular Imaging
  • [Show abstract] [Hide abstract]
    ABSTRACT: We report a rare case in an 86-year-old woman with symptoms of exercise intolerance, fatigability, worsening lower extremity edema, and normal ejection fraction on echocardiographic examination who presented with a presumptive diagnosis of heart failure with preserved ejection fraction (HFpEF). Hemodynamic studies revealed that she had normal left-sided filling pressures, mildly elevated pulmonary pressures with normal pulmonary vasculature resistance, and evidence of right ventricular dysfunction. Significant shunting was also detected with a step-up blood oxygen saturation from superior vena cava to right atrium and a calculated pulmonary-to-systemic blood flow ratio of 3.9. Contrast-enhanced multidetector cardiac computed tomography confirmed the presence of a patent foramen ovale, a sinus venosus atrial septal defect, and 3 anomalous pulmonary venous communications to the right atrium and superior vena cava. We hereby present one of the oldest diagnosed cases of sinus venosus defect with anomalous pulmonary venous return as a rare cause of recent-onset dyspnea, volume overload, and functional intolerance in an 86-year-old woman with an initial misdiagnosis of HFpEF.
    No preview · Article · Sep 2015
  • Source

    Full-text · Dataset · Sep 2015
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background: High-density lipoprotein (HDL) particles have properties beyond reverse cholesterol transport. We hypothesized that their protection extends to inflammation-related disease. The predictive value of HDL particle subclasses and inflammatory markers was studied for noncardiovascular, noncancer chronic inflammation-related death and hospitalization, and for incident cardiovascular disease (CVD). Methods and results: A multiethnic, multicenter, prospective observational study was conducted in 6475 men and women (aged 45 to 84 years) free of known CVD at baseline with median follow-up of 10.1 years. Fasting venous samples were analyzed for baseline lipid profile and lipoprotein particles. We focused on the HDL family of variables (small-, medium-, and large-diameter HDL particles and HDL cholesterol). Analyses identified the sum of small- plus medium-diameter HDL particles as important. Small- plus medium-diameter HDL particles were inversely associated with diagnostic code-based noncardiovascular, noncancer chronic inflammation-related death and hospitalization (n=1054) independent of covariates: relative risk per SD 0.85 (95% CI: 0.79 to 0.91, P<0.0001). Small- plus medium-diameter HDL particles were also associated with adjudicated fatal and nonfatal coronary heart disease events (n=423): relative risk per SD 0.88 (95% CI 0.77 to 0.98, P=0.02). Conclusions: Small- plus medium-diameter HDL particles are an independent predictor for noncardiovascular, noncancer chronic inflammation-related death and hospitalization and for coronary heart disease events in subjects initially free of overt CVD. These findings support the hypothesis that smaller HDL particles of diameter <9.4 nm have anti-inflammatory properties in the general population.
    Preview · Article · Sep 2015 · Journal of the American Heart Association
  • [Show abstract] [Hide abstract]
    ABSTRACT: Post-contrast myocardial T1 (T1myo,c) values have been shown to be sensitive to myocardial fibrosis. Recent studies have shown differences in results obtained from T1myo,c and extracellular volume fraction (ECV) with respect to percentage fibrosis. By exploring the relationship between blood plasma volume and T1myo,c, the underlying basis for the divergence can be explained. Furthermore, dose administration based on body mass index (BMI), age and gender can mitigate the divergence in results. Inter-subject comparison of T1myo,c required adjustment for dose (in mmol/kg), time and glomerular filtration rate. Further adjustment for effective dose based on lean muscle mass reflected by blood/plasma volume was performed. A test case of 605 subjects from the MESA study who had undergone pre- and post-contrast T1 mapping was studied. T1myo,c values were compared between subjects with and without metabolic syndrome (MetS), between smoking and non-smoking subjects, and subjects with and without impaired glucose tolerance, before and after dose adjustment based on plasma volume. Comparison with ECV (which is dose independent), pre-contrast myocardial T1 and blood normalized myocardial T1 values was also performed to validate the correction. There were significant differences in T1myo,c (post plasma volume correction) and ECV between current and former smokers (p value 0.017 and 0.01, respectively) but not T1myo,c prior to correction (p = 0.12). Prior to dose adjustment for plasma volume, p value was <0.001 for T1myo,c between MetS and non-MetS groups and was 0.13 between subjects with and without glucose intolerance; after adjustment for PV, p value was 0.63 and 0.99. Corresponding ECV p values were 0.44 and 0.99, respectively. Overall, ECV results showed the best agreement with PV corrected T1myo,c (mean absolute difference in p values = 0.073) and pre-contrast myocardial T1 in comparison with other measures (T1myo,c prior to correction, blood/plasma T1 value normalized myocardium). Weight-based contrast dosing administered in mmol/kg results in a bias in T1 values which can lead to erroneous conclusions. After adjustment for lean muscle mass based on plasma volume, results from T1myo,c were in line with ECV derived results. Furthermore, the use of a modified equivalent dose adjusted for BMI, age, sex and hematocrit can be adopted for quantitative imaging.
    No preview · Article · Sep 2015 · The international journal of cardiovascular imaging
  • [Show abstract] [Hide abstract]
    ABSTRACT: Aims: To assess the test-retest, intra- and inter-reader reliability of thoracic aorta measurements by magnetic resonance imaging (MRI). Methods and results: Twenty-five participants underwent aortic MRI twice over 13 ± 7 days. All aortic variables from baseline and repeat MR were analysed using a semi-automated method by the ARTFUN software. To assess the inter-study reproducibility of aortic variables, we calculated intraclass correlation coefficient (ICC) for individual aortic measurements. Intra- and inter-observer variability was also assessed using the baseline MR data. Mean ascending aortic strain had moderate inter-study reproducibility (11.53 ± 6.44 vs. 10.55 ± 6.64, P = 0.443, ICC = 0.53, P < 0.01). Mean descending aortic strain and arch pulse wave velocity (PWV) had good inter-study reproducibility (descending aortic strain: 8.65 ± 5.30 vs. 8.35 ± 5.26, P = 0.706, ICC = 0.74, P < 0.001; PWV: 9.92 ± 4.18 vs. 9.94 ± 4.55, P = 0.968, ICC = 0.77, P < 0.001, respectively). All aortic variables had excellent intra- and inter-observer reproducibility (intra-: ICC range, 0.87-0.99, inter-: ICC range, 0.56-0.99, respectively). Conclusion: Inter-study reproducibility of all aortic variables was acceptable. Intra- and inter-observer reproducibility of all aortic variables was excellent. MRI can provide a repeatable method of measuring aortic structural and functional parameters.
    No preview · Article · Sep 2015 · European Heart Journal Cardiovascular Imaging
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objective Obesity is associated with changes in both right (RV) and left (LV) ventricular morphology, but the biological basis of this finding is not well established. We examined whether adipokine levels were associated with RV morphology and function in a population-based multiethnic sample free of clinical cardiovascular disease. Methods We examined relationships of leptin, resistin, TNF-α, and adiponectin with RV morphology and function (from cardiac MRI) in participants (n = 1,267) free of clinical cardiovascular disease from the Multi-Ethnic Study of Atherosclerosis (MESA)-RV study. Multivariable regressions (linear, quantile [25th and 75th] and generalized additive models [GAM]) were used to examine the independent association of each adipokine with RV mass, RV end-diastolic volume (RVEDV), RV end-systolic volume (RVESV), RV stroke volume (RVSV) and RV ejection fraction (RVEF). Results Higher leptin levels were associated with significantly lower levels of RV mass, RVEDV, RVESV and stroke volume, but not RVEF, after adjustment for age, gender, race, height and weight. These associations were somewhat attenuated but still significant after adjustment for traditional risk factors and covariates, and were completely attenuated when correcting for the respective LV measures. There were no significant interactions of age, gender, or race/ethnicity on the relationship between the four adipokines and RV structure or function. Conclusions Leptin levels are associated with favorable RV morphology in a multi-ethnic population free of cardiovascular disease, however these associations may be explained by a yet to be understood bi-ventricular process as this association was no longer present after adjustment for LV values. These findings complement the associations previously shown between adipokines and LV structure and function in both healthy and diseased patients. The mechanisms linking adipokines to healthy cardiovascular function require further investigation.
    Preview · Article · Sep 2015 · PLoS ONE
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Aim: Previous animal studies have demonstrated differences in perfusion and perfusion reserve between the subendocardium and subepicardium. 320-row computed tomography (CT) with sub-millimetre spatial resolution allows for the assessment of transmural differences in myocardial perfusion reserve (MPR) in humans. We aimed to test the hypothesis that MPR in all myocardial layers is determined by age, gender, and cardiovascular risk profile in patients with ischaemic symptoms or equivalent but without obstructive coronary artery disease (CAD). Methods and results: A total of 149 patients enrolled in the CORE320 study with symptoms or signs of myocardial ischaemia and absence of significant CAD by invasive coronary angiography were scanned with static rest and stress CT perfusion. Myocardial attenuation densities were assessed at rest and during adenosine stress, segmented into 3 myocardial layers and 13 segments. MPR was higher in the subepicardium compared with the subendocardium (124% interquartile range [45, 235] vs. 68% [22,102], P < 0.001). Moreover, MPR in the septum was lower than in the inferolateral and anterolateral segments of the myocardium (55% [19, 104] vs. 89% [37, 168] and 124% [54, 270], P < 0.001). By multivariate analysis, high body mass index was significantly associated with reduced MPR in all myocardial layers when adjusted for cardiovascular risk factors (P = 0.02). Conclusion: In symptomatic patients without significant coronary artery stenosis, distinct differences in endocardial-epicardial distribution of perfusion reserve may be demonstrated with static CT perfusion. Low MPR in all myocardial layers was observed specifically in obese patients.
    Full-text · Article · Sep 2015 · European Heart Journal Cardiovascular Imaging

Publication Stats

20k Citations
3,327.28 Total Impact Points


  • 1993-2016
    • Johns Hopkins University
      • • Department of Medicine
      • • Division of Cardiology
      Baltimore, Maryland, United States
  • 1998-2015
    • Johns Hopkins Medicine
      • • Division of Cardiology
      • • Department of Medicine
      • • Division of Cardiac Surgery
      Baltimore, Maryland, United States
  • 2009
    • University of Washington Seattle
      • Department of Biostatistics
      Seattle, Washington, United States
  • 2007
    • Federal University of Rio de Janeiro
      Rio de Janeiro, Rio de Janeiro, Brazil
  • 2006
    • Columbia University
      New York, New York, United States
    • University of California, Los Angeles
      Los Ángeles, California, United States
  • 2004
    • Ethianum Klinik Heidelberg
      Heidelburg, Baden-Württemberg, Germany
    • University of Zurich
      Zürich, Zurich, Switzerland
  • 2002
    • Johns Hopkins Bloomberg School of Public Health
      • Department of Epidemiology
      Baltimore, Maryland, United States
  • 1999
    • Northwestern University
      Evanston, Illinois, United States
  • 1997
    • University of Baltimore
      Baltimore, Maryland, United States
  • 1996
    • University of Maryland, Baltimore
      • Division of Cardiology
      Baltimore, MD, United States
  • 1994
    • University of Pennsylvania
      • Department of Bioengineering
      Filadelfia, Pennsylvania, United States