João A C Lima

Johns Hopkins University, Baltimore, Maryland, United States

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Publications (319)2191.89 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: PurposeTo 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.ResultsThe 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.J. Magn. Reson. Imaging 2014. © 2014 Wiley Periodicals, Inc.
    Journal of Magnetic Resonance Imaging 09/2014; · 2.57 Impact Factor
  • Journal of the American College of Cardiology 07/2014; 64(4):422. · 14.09 Impact Factor
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    ABSTRACT: Purpose To investigate the association between left atrial (LA) function and left ventricular myocardial fibrosis using cardiac magnetic resonance (MR) imaging in a multi-ethnic population. Materials and Methods For this HIPAA-compliant study, the institutional review board at each participating center approved the study protocol, and all participants provided informed consent. Of 2839 participants who had undergone cardiac MR in 2010-2012, 143 participants with myocardial scar determined with late gadolinium enhancement and 286 age-, sex-, and ethnicity-matched control participants were identified. LA volume, strain, and strain rate were analyzed by using multimodality tissue tracking from cine MR imaging. T1 mapping was applied to assess diffuse myocardial fibrosis. The association between LA parameters and myocardial fibrosis was evaluated with the Student t test and multivariable regression analysis. Results The scar group had significantly higher minimum LA volume than the control group (mean, 22.0 ± 10.5 [standard deviation] vs 19.0 ± 7.8, P = .002) and lower LA ejection fraction (45.9 ± 10.7 vs 51.3 ± 8.7, P < .001), maximal LA strain (Smax) (25.4 ± 10.7 vs 30.6 ± 10.6, P < .001) and maximum LA strain rate (SRmax) (1.08 ± 0.45 vs 1.29 ± 0.51, P < .001), and lower absolute LA strain rate at early diastolic peak (SRE) (-0.77 ± 0.42 vs -1.01 ± 0.48, P < .001) and LA strain rate at atrial contraction peak (SRA) (-1.50 ± 0.62 vs -1.78 ± 0.69, P < .001) than the control group. T1 time 12 minutes after contrast material injection was significantly associated with Smax (β coefficient = 0.043, P = .013), SRmax (β coefficient = 0.0025, P = .001), SRE (β coefficient = -0.0016, P = .027), and SRA (β coefficient -0.0028, P = .01) in the regression model. T1 time 25 minutes after contrast material injection was significantly associated with SRmax (β coefficient = 0.0019, P = .016) and SRA (β coefficient = -0.0022, P = .034). Conclusion Reduced LA regional and global function are related to both replacement and diffuse myocardial fibrosis processes. Clinical trial registration no. NCT00005487 © RSNA, 2014 Online supplemental material is available for this article.
    Radiology 07/2014; · 6.34 Impact Factor
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    ABSTRACT: The association of longitudinal changes in left ventricular (LV) structure and function with myocardial fibrosis is unclear. We relate temporal changes in body size-indexed LV mass (LVMi) and end-diastolic volume indexed to body surface area , LV mass-to-volume ratio, and LV ejection fraction (LVEF) from cine cardiac magnetic resonance for 10 years, with replacement scar assessed from late gadolinium enhancement, and lower postcontrast T1 times reflecting greater diffuse myocardial fibrosis measured at the end of the follow-up period. All participants (n=1813) who underwent cardiac magnetic resonance twice as part of the Multi-Ethnic Study of Atherosclerosis 10 years apart were included. Multivariable logistic and linear regression models adjusted for cardiovascular risk factors measured the association of 10-year changes in LV structure and function, with fibrosis measured at follow-up. The presence of LV scar at year 10 was cross-sectionally associated with higher LVMi (≈10 g/m(2)), higher mass-to-volume ratio (0.1-0.2 g/mL), but lower LVEF (≈4%) and longitudinally with 3% decrease in LVEF and 0.7% greater end-diastolic volume indexed to body surface area in men for 10 years. Lower postcontrast T1 times at year 10 were associated cross-sectionally with lower LVMi (r=0.33), end-diastolic volume indexed to body surface area (r=0.25), and LVEF (in men only: r=0.14) and longitudinally with a decrease in LVMi (r=0.20) and reduction in LVEF (in men only: r=0.15). Sustained hypertension for 10 years was associated with increased LVMi and higher diffuse and replacement fibrosis at follow-up. During a 10-year period, increased concentric hypertrophy in women and LV dilatation in men were associated with replacement fibrosis, whereas decreasing LVMi was associated with diffuse fibrosis. Hypertension-induced remodeling was related to enhanced replacement and diffuse fibrosis, as well as hypertrophy.
    Hypertension 06/2014; · 6.87 Impact Factor
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    ABSTRACT: To evaluate long-term changes in diffuse myocardial fibrosis using cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) and T1 mapping. Patients with chronic stable cardiomyopathy and stable clinical status (n = 52) underwent repeat CMR at a 6 month or greater follow up interval and had LGE and left ventricular (LV) T1 mapping CMR. Diffuse myocardial fibrosis (excluding areas of focal myocardial scar) was assessed by post gadolinium myocardial T1 times. Mean baseline age of 52 patients (66 % male) was 35 ± 19 years with a mean interval between CMR examinations of 2.0 ± 0.8 years. CMR parameters, including LV mass and ejection fraction, showed no change at follow-up CMR (p > 0.05). LVT1 times (excluding focal scar) decreased over the study interval (from 468 ± 106 to 434 ± 82 ms, p = 0.049). 38 Patients had no visual LGE-, while 14 were LGE+. For LGE- patients, greater change in LV mass and end systolic volume index were associated with change in T1 time (β = -2.03 ms/g/m(2), p = 0.035 and β = 2.1 ms/mL/m(2), p = 0.029, respectively). For LGE+ patients, scar size was stable between CMR1 and CMR2 (10.7 ± 13.8 and 11.5 ± 13.9 g, respectively, p = 0.32). These results suggest that diffuse myocardial fibrosis, as assessed by T1 mapping, progresses over time in patients with chronic stable cardiomyopathy.
    The international journal of cardiovascular imaging. 06/2014;
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    ABSTRACT: Previous research suggests that elevated pulse pressure (PP) is a risk factor for atrial fibrillation (AF) independently of mean arterial pressure (MAP). PP may serve as an indirect measure of aortic stiffness (reduced distensibility), but whether directly measured aortic distensibility is related to risk for AF has not yet been studied. This analysis included 6,630 participants aged 45 to 84 years from the Multi-Ethnic Study of Atherosclerosis. At baseline, blood pressure and other relevant covariates were measured using standardized protocols. Magnetic resonance imaging-based aortic distensibility was measured in 3,441 participants. Incident AF was identified from hospitalization discharge codes and Medicare claims. Multivariate Cox models were used to estimate the association of blood pressure components and aortic distensibility with AF risk. During a mean follow-up of 7.8 years, 307 AF events (137 among those with aortic distensibility measurements) were identified. In multivariate-adjusted models simultaneously including MAP and PP, each 1-SD increase in PP was associated with a 29% increased risk of AF (95% confidence interval 5% to 59%, p = 0.02), with MAP not being associated with increased AF risk. Overall, aortic distensibility was not consistently associated with AF risk: after removing outliers, each 1-SD increase in aortic distensibility was associated with a 9% increased risk of AF (95% confidence interval -22% to 51%, p = 0.63). In conclusion, in this large community-based cohort, we found that PP, but not MAP or aortic distensibility, was a significant risk factor for AF, emphasizing the importance of PP when assessing the risk for developing AF. Our results cast doubt on the clinical utility of aortic distensibility as a predictor for the development of AF.
    The American journal of cardiology. 06/2014;
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    ABSTRACT: Purpose To compare the diagnostic performance of myocardial computed tomographic (CT) perfusion imaging and single photon emission computed tomography (SPECT) perfusion imaging in the diagnosis of anatomically significant coronary artery disease (CAD) as depicted at invasive coronary angiography. Materials and Methods This study was approved by the institutional review board. Written informed consent was obtained from all patients. Sixteen centers enrolled 381 patients from November 2009 to July 2011. Patients underwent rest and adenosine stress CT perfusion imaging and rest and either exercise or pharmacologic stress SPECT before and within 60 days of coronary angiography. Images from CT perfusion imaging, SPECT, and coronary angiography were interpreted at blinded, independent core laboratories. The primary diagnostic parameter was the area under the receiver operating characteristic curve (Az). Sensitivity and specificity were calculated with use of prespecified cutoffs. The reference standard was a stenosis of at least 50% at coronary angiography as determined with quantitative methods. Results CAD was diagnosed in 229 of the 381 patients (60%). The per-patient sensitivity and specificity for the diagnosis of CAD (stenosis ≥50%) were 88% (202 of 229 patients) and 55% (83 of 152 patients), respectively, for CT perfusion imaging and 62% (143 of 229 patients) and 67% (102 of 152 patients) for SPECT, with Az values of 0.78 (95% confidence interval: 0.74, 0.82) and 0.69 (95% confidence interval: 0.64, 0.74) (P = .001). The sensitivity of CT perfusion imaging for single- and multivessel CAD was higher than that of SPECT, with sensitivities for left main, three-vessel, two-vessel, and one-vessel disease of 92%, 92%, 89%, and 83%, respectively, for CT perfusion imaging and 75%, 79%, 68%, and 41%, respectively, for SPECT. Conclusion The overall performance of myocardial CT perfusion imaging in the diagnosis of anatomic CAD (stenosis ≥50%), as demonstrated with the Az, was higher than that of SPECT and was driven in part by the higher sensitivity for left main and multivessel disease. © RSNA, 2014.
    Radiology 05/2014; · 6.34 Impact Factor
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    ABSTRACT: 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 β = 0.32, P < .001), male sex (standardized β = 0.36, P < .001), body mass index (BMI) (standardized β = 0.26, P < .001), and duration of diabetes (standardized β = 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. © RSNA, 2014 Clinical trial registration no. NCT00488033 Online supplemental material is available for this article.
    Radiology 05/2014; · 6.34 Impact Factor
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    ABSTRACT: The goal of this study was to assess the association between left atrial (LA) volume and function measured with feature-tracking cardiac magnetic resonance (CMR) and development of heart failure (HF) in asymptomatic individuals. Whether alterations of LA structure and function precede or follow HF development remains incompletely understood. We hypothesized that significant alterations of LA deformation and architecture precede the development of HF in the general population. In a case-control study nested in MESA (Multi-Ethnic Study of Atherosclerosis), baseline LA volume and function assessed using CMR feature-tracking were compared between 112 participants with incident HF (mean age 68.4 ± 8.2 years; 66% men) and 224 age- and sex-matched controls (mean age 67.7 ± 8.9 years; 66% men). Participants were followed up for 8 years. All individuals were in normal sinus rhythm at the time of imaging, without any significant valvular abnormalities and free of clinical cardiovascular diseases. Individuals with incident HF had greater maximal and minimal LA volume indexes (LAVImin) than control subjects (40 ± 13 mm(3)/m(2) vs. 33 ± 10 mm(3)/m(2) [p <0.001] for maximal LA index and 25 ± 11 mm(3)/m(2) vs. 17 ± 7 mm(3)/m(2) [p <0.001] for LAVImin). The HF case subjects also had smaller global peak longitudinal atrial strain (PLAS) (25 ± 11% vs. 38 ± 16%; p <0.001) and lower LA emptying fraction (40 ± 11% vs. 48 ± 9%; p <0.001) at baseline. After adjustment for traditional cardiovascular risk factors, left ventricular mass, and N-terminal pro-B-type natriuretic peptide, global PLAS (odds ratio: 0.36 per SD [95% confidence interval: 0.22 to 0.60]) and LAVImin (odds ratio: 1.65 per SD [95% confidence interval: 1.04 to 2.63]) were independently associated with incident HF. Deteriorations in LA structure and function preceded development of HF. Lower global PLAS and higher LAVImin, measured using CMR feature-tracking, were independent markers of incident HF in a multiethnic population of asymptomatic individuals.
    JACC. Cardiovascular imaging 05/2014; · 14.29 Impact Factor
  • Atul R Chugh, Joao A C Lima
    Circulation Research 04/2014; 114(8):1222-4. · 11.86 Impact Factor
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    ABSTRACT: 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.
    Current Cardiovascular Imaging Reports 04/2014; 7:9269.
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    ABSTRACT: -Fibroblast growth factor-23 (FGF-23) is a phosphate regulatory hormone that directly stimulates left ventricular hypertrophy in experimental models. The role of FGF-23 in cardiovascular disease development in the general population is unclear. We tested associations of FGF-23 with major subclinical and clinical cardiovascular disease outcomes in a large prospective cohort. -We evaluated 6,547 participants from the Multi-Ethnic Study of Atherosclerosis (MESA) who were initially free of cardiovascular disease. We measured serum FGF-23 using the Kainos immunoassay. The MESA measured left ventricular (LV) mass by magnetic resonance imaging, coronary calcium (CAC) by computed tomography, and carotid intima-medial thickness (IMT) by ultrasound. The MESA adjudicated incident heart failure, coronary heart disease, and stoke by medical record review. After adjustment, the highest FGF-23 quartile was associated with an estimated 2.4 gram greater LV mass (95% CI 0.4, 4.5 greater) and a 26% greater odds of higher CAC scores (95% CI 9% to 46% greater) compared to the lowest quartile. Over 7.5 years follow-up, each 20-pg/mL higher FGF-23 concentration was associated with a 19% greater risk of heart failure (95% CI 3% to 37% greater) and a 14% greater risk of coronary heart disease (95% CI 1% to 28% greater). FGF-23 was not associated with carotid IMT or stroke. -Higher serum FGF-23 concentrations are associated with subclinical cardiac disease and with new heart failure and coronary disease events, but not with carotid IMT or stroke. FGF-23 may be a novel cardiovascular risk factor in the general population.
    Circulation Heart Failure 03/2014; · 6.68 Impact Factor
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    ABSTRACT: Background: Subclinical cardiovascular disease is prevalent in patients with Metabolic Syndrome (MetSyn). Left ventricular (LV) circumferential strain (εCC) and longitudinal strain (εLL), assessed by Speckle Tracking Echocardiography (STE), are indices of systolic function: shortening is indicated by negative strain, and thus, the more negative the strain, the better the LV systolic function. They have been used to demonstrate subclinical ventricular dysfunction in several clinical disorders. Objective: We hypothesized that MetSyn is associated with impaired myocardial function, as assessed by STE. Methods: We analyzed Multi-Ethnic Study of Atherosclerosis (MESA) participants who underwent STE and were evaluated for all MetSyn components. Results: Among the 133 participants included [women: 63%; age: 65 ± 9 years (mean ± SD)], the prevalence of MetSyn was 31% (41/133). Individuals with MetSyn had lower εCC and lower εLL than those without MetSyn (-16.3% ± 3.5% vs. -18.4% ± 3.7%, p < 0.01; and -12.1% ± 2.5% vs. -13.9% ± 2.3%, p < 0.01, respectively). The LV ejection fraction (LVEF) was similar in both groups (p = 0.09). In multivariate analysis, MetSyn was associated with less circumferential myocardial shortening as indicated by less negative εCC (B = 2.1%, 95%CI:0.6 3.5, p < 0.01) even after adjusting for age, ethnicity, LV mass, and LVEF). Likewise, presence of MetSyn (B = 1.3%, 95%CI:0.3 2.2, p < 0.01) and LV mass (B = 0.02%, 95% CI: 0.01-0.03, p = 0.02) were significantly associated with less longitudinal myocardial shortening as indicated by less negative εLL after adjustment for ethnicity, LVEF, and creatinine. Conclusion: Left ventricular εCC and εLL, markers of subclinical cardiovascular disease, are impaired in asymptomatic individuals with MetSyn and no history of myocardial infarction, heart failure, and/or LVEF < 50%.
    Arquivos brasileiros de cardiologia 03/2014; · 1.32 Impact Factor
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    ABSTRACT: Background Although atrial fibrillation (AF) triggers are known, the underlying AF substrate is less well understood. The goal of our study was to explore correlations between electrophysiological and structural characteristics of atria in patients with paroxysmal AF and individuals at AF risk. Methods Patients in sinus rhythm (N = 90; age 57 ± 10 year; 55 men [63.2%]) with structural heart disease and paroxysmal AF (n = 12 [13%]), or with AF risk factors and LVEF > 35% (n = 78), underwent SAECG and cardiac magnetic resonance study. Interatrial and epicardial fat was analyzed with a Dark-blood DIR-prepared Fat-Water-separated sequence in the horizontal longitudinal axis. All local P-wave extrema were identified on SAECG leads during sinus rhythm. A P-wave fragmentation (Pf) was defined as an absolute difference between adjacent extrema which was above three standard deviations of noise, and was normalized by the duration of the P wave in the corresponding lead. ResultsThe Pf was greater on the filtered than on the unfiltered P-SAECG signal (13.1 ± 3.8 vs. 3.4 ± 1.2; P < 0.0001). Pf was the greatest on the Y lead (13.0 ± 3.5 on Y lead vs. 12.1 ± 3.4 on Z lead; P = 0.003. Pf on Z lead correlated with interatrial fat index (r = 0.544; P = 0.001). Epicardial fat significantly correlated with body mass index (BMI; r = 0.302; P = 0.015). After adjustment for BMI, left atrium (LA) size, epicardial fat, and interatrial septum width, interatrial fat independently associated with the Pf on Z lead (β-coefficient 0.009 [95%CI 0.0003–0.019]; P = 0.043). Conclusions Infiltrated atrial fat correlates with discontinuous conduction on posterior LA wall and represents AF early substrate.
    Annals of Noninvasive Electrocardiology 03/2014; 19(2). · 1.08 Impact Factor
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    ABSTRACT: Transseptal puncture (TSP) allows left atrial access for curative procedures. Intracardiac echocardiography (ICE) provides direct visualization of the interatrial septum (IAS), but adds time and expense. We reviewed 100 cardiac multidetector computed tomography (MDCT) scans of patients undergoing AF ablation to determine if the angulation and orientation of the IAS are conserved or variable. Significant variability may suggest a potential role for direct visualization of the IAS during TSP. We reviewed 100 MDCT scans obtained prior to AF ablation. The IAS plane at the fossa ovalis was identified in axial and coronal images. We measured the angle of the septum relative to an orthogonal plane. Optimal needle orientation was defined as perpendicular to the fossa ovalis. The mean axial plane angle was -60.6 ± 10.6°; range, -29.5° to -88.7°). The mean coronal plane angle was 142.6 ± 9.1°; range, 115° to 162°). The axial angle corresponded to variation in the "clock-face" orientation of the needle during puncture, and was calculated between 4 and 6 o'clock. Coronal plane angulation corresponds to the curvature of the needle tip, which varied by 47°. We found no association between patient characteristics and IAS angle. The septal orientation in the axial plane varied widely and was not predicted by clinical variables such as atrial size or prior valve surgery. The high degree of interpatient variability observed suggests that direct visualization of the septum may be helpful in the performance of TSP.
    The Journal of invasive cardiology 03/2014; 26(3):128-131. · 1.57 Impact Factor
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    ABSTRACT: Purpose To determine if carotid plaque morphology and composition with magnetic resonance (MR) imaging can be used to identify asymptomatic subjects at risk for cardiovascular events. Materials and Methods Institutional review boards at each site approved the study, and all sites were Health Insurance Portability and Accountability Act (HIPAA) compliant. A total of 946 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) were evaluated with MR imaging and ultrasonography (US). MR imaging was used to define carotid plaque composition and remodeling index (wall area divided by the sum of wall area and lumen area), while US was used to assess carotid wall thickness. Incident cardiovascular events, including myocardial infarction, resuscitated cardiac arrest, angina, stroke, and death, were ascertained for an average of 5.5 years. Multivariable Cox proportional hazards models, C statistics, and net reclassification improvement (NRI) for event prediction were determined. Results Cardiovascular events occurred in 59 (6%) of participants. Carotid IMT as well as MR imaging remodeling index, lipid core, and calcium in the internal carotid artery were significant predictors of events in univariate analysis (P < .001 for all). For traditional risk factors, the C statistic for event prediction was 0.696. For MR imaging remodeling index and lipid core, the C statistic was 0.734 and the NRI was 7.4% and 15.8% for participants with and those without cardiovascular events, respectively (P = .02). The NRI for US IMT in addition to traditional risk factors was not significant. Conclusion The identification of vulnerable plaque characteristics with MR imaging aids in cardiovascular disease prediction and improves the reclassification of baseline cardiovascular risk. © RSNA, 2014.
    Radiology 02/2014; · 6.34 Impact Factor
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    ABSTRACT: -Tagged cardiac magnetic resonance (CMR) provides detailed information on regional myocardial function and mechanical behavior. T1 mapping by CMR allows non-invasive quantification of myocardial extracellular expansion (ECE) which has been related to interstitial fibrosis in previous clinical and sub-clinical studies. We assessed gender associated differences in the relation of ECE to LV remodeling and myocardial systolic and diastolic deformation in a large community based multi-ethnic population. -Mid-ventricular mid-wall peak circumferential shortening and early diastolic strain rate (EDSR); LV torsion and torsional recoil rate were determined using CMR tagging. Mid ventricular short axis T1 maps were acquired in the same examination pre and post-contrast injection using Modified Look-Locker Inversion Recovery sequence (MOLLI). Multivariable linear regression (B= estimated regression coefficient) was used to adjust for risk factors and sub-clinical disease measures. Of 1230 participants, 114 participants had visible myocardial scar by late gadolinium enhancement. Participants without visible myocardial scar (n=1116) had no previous history of clinical events. In the latter group, multivariable linear regression demonstrated that lower post-contrast T1 times, reflecting greater ECE were associated with lower circumferential shortening (B=-0.1, p=0.0001), lower end diastolic volume index (LVEDVi) (B=0.6, p=0.0001) and lower LV end diastolic mass index (LVMi) (B=0.4, p=0.0001). In addition, lower post-contrast T1 times were associated with lower EDSR (B=0.01, p=0.03) in women only; and lower LV torsion (B=0.005, p=0.03) a lower LV ejection fraction (B=0.2, p=0.01) in men only. -Greater ECE is associated with reduced LVEDVi and LVMi in a large multi-ethnic population without history of previous cardiovascular events. In addition, greater ECE is associated with reduced circumferential shortening, lower EDSR, and a preserved ejection fraction in women; while in men, greater ECE is associated with greater LV dysfunction manifested as reduced circumferential shortening, reduced LV Torsion and reduced ejection fraction.
    Circulation Cardiovascular Imaging 02/2014; · 5.80 Impact Factor
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    ABSTRACT: We investigated whether the addition of left atrial (LA) size determined by echocardiography improves cardiovascular risk prediction in young adults over and above the clinically established Framingham 10-year global CV risk score (FRS). We included white and black CARDIA participants who had echocardiograms in Year-5 examination (1990-91). The combined endpoint after 20 years was incident fatal or non-fatal cardiovascular disease: myocardial infarction, heart failure, cerebrovascular disease, peripheral artery disease, and atrial fibrillation/flutter. Echocardiography-derived M-mode LA diameter (LAD; n = 4082; 149 events) and 2D four-chamber LA area (LAA; n = 2412; 77 events) were then indexed by height or body surface area (BSA). We used Cox regression, areas under the receiver operating characteristic curves (AUC), and net reclassification improvement (NRI) to assess the prediction power of LA size when added to calculated FRS or FRS covariates. The LAD and LAA cohorts had similar characteristics; mean LAD/height was 2.1 ± 0.3 mm/m and LAA/height 9.3 ± 2.0 mm(2)/m. After indexing by height and adjusting for FRS covariates, hazard ratios were 1.31 (95% CI 1.12, 1.60) and 1.43 (95% CI 1.13, 1.80) for LAD and LAA, respectively; AUC was 0.77 for LAD and 0.78 for LAA. When LAD and LAA were indexed to BSA, the results were similar but slightly inferior. Both LAD and LAA showed modest reclassification ability, with non-significant NRIs. LA size measurements independently predict clinical outcomes. However, it only improves discrimination over clinical parameters modestly without altering risk classification. Indexing LA size by height is at least as robust as by BSA. Further research is needed to assess subgroups of young adults who may benefit from LA size information in risk stratification.
    European heart journal cardiovascular Imaging. 02/2014;
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    ABSTRACT: It is known that expanded epicardial fat is associated with atrial fibrillation (AF). However, infiltrated intraatrial fat has not been previously quantified in individuals at risk as determined by the ARIC AF risk score. Patients in sinus rhythm (N=90, age 57±10years; 55 men [63.2%]), in 3 groups at risk of AF as determined by the ARIC AF risk score [low (≤11 points; n=15), moderate (12-18 points; n=40), high (≥19 points; n=23) risk of AF], and paroxysmal AF (n=12) underwent cardiac magnetic resonance study. Intraatrial and epicardial fat was analyzed with a Dark-blood DIR-prepared Fat-Water-separated sequence in the horizontal longitudinal axis. OsiriX DICOM viewer (Geneva, Switzerland) was used to quantify the intraatrial fat area. Width of the cephalad portion of the interatrial septum was measured at the level of the fossa ovalis. Intraatrial fat monotonically increased with growing AF risk in study groups (low AF risk 16±4 vs. moderate AF risk 32±18 vs. high AF risk 81±83mm(2); ANOVA P=0.012). Log-transformed intraatrial fat predicted ARIC AF risk score in multivariate ordered probit regression after adjustment for sex, race, left and right atrial area indices, and body mass index (β-coefficient 0.50 [95% CI 0.03-0.97]; P=0.037), whereas epicardial fat did not. Interatrial septum width showed similar association (3.0±1.4 vs. 5.0±1.8 vs. 7.1±2.7mm; ANOVA P<0.001; adjusted β-coefficient 2.80 [95% CI 1.19-4.41]; P=0.001). Infiltrated intraatrial fat characterizes evolving substrate in individuals at risk of AF.
    International journal of cardiology 01/2014; · 6.18 Impact Factor
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    ABSTRACT: We investigate how early adult and 20-year changes in modifiable cardiovascular risk factors (MRF) predict left atrial dimension (LAD) at age 43-55 years. The Coronary Artery Risk Development in Young Adults (CARDIA) study enrolled black and white adults (1985-1986). We included 2903 participants with echocardiography and MRF assessment in follow-up years 5 and 25. At years 5 and 25, LAD was assessed by M-mode echocardiography, then indexed to body surface area (BSA) or height. Blood pressure (BP), body mass index (BMI), heart rate (HR), smoking, alcohol use, diabetes and physical activity were defined as MRF. Associations of MRF with LAD were assessed using multivariable regression adjusted for age, ethnicity, gender and year-5 left atrial (LA) size. The participants were 30±4 years; 55% white; 44% men. LAD and LAD/height were modest but significantly higher over the follow-up period, but LAD/BSA decreased slightly. Increased baseline and 20-year changes in BP were related to enlargement of LAD and indices. Higher baseline and changes in BMI were also related to higher LAD and LAD/height, but the opposite direction was found for LAD/BSA. Increase in baseline HR was related to lower LAD but not LAD indices, when only baseline covariates were included in the model. However, baseline and 20-year changes in HR were significantly associated to LA size. In a biracial cohort of young adults, the most robust predictors for LA enlargement over a 20-year follow-up period were higher BP and BMI. However, an inverse direction was found for the relationship between BMI and LAD/BSA. HR showed an inverse relation to LA size.
    BMJ Open 01/2014; 4(1):e004001. · 1.58 Impact Factor

Publication Stats

10k Citations
2,191.89 Total Impact Points

Institutions

  • 2001–2014
    • Johns Hopkins University
      • • Department of Medicine
      • • Division of Cardiology
      • • Department of Radiology
      Baltimore, Maryland, United States
  • 1970–2014
    • Johns Hopkins Medicine
      • • Department of Medicine
      • • Division of Cardiology
      • • Department of Biomedical Engineering
      Baltimore, Maryland, United States
  • 2013
    • U.S. Food and Drug Administration
      • Office of Science and Engineering Laboratories
      Washington, Washington, D.C., United States
    • Toshiba Corporation
      Edo, Tōkyō, Japan
  • 2011–2013
    • University of Pennsylvania
      • Perelman School of Medicine
      Philadelphia, Pennsylvania, United States
    • Northwestern University
      • Department of Radiology
      Evanston, IL, United States
    • Hospices Civils de Lyon
      Lyons, Rhône-Alpes, France
    • Mount Sinai School of Medicine
      • Department of Radiology
      Manhattan, NY, United States
    • University of California, Los Angeles
      Los Angeles, California, United States
  • 2010–2013
    • National Institutes of Health
      • Radiology and Imaging Sciences Department
      Bethesda, MD, United States
    • Naval Medical Center San Diego
      • Division of Cardiology
      San Diego, California, United States
    • University of Toronto
      • Division of Cardiology
      Toronto, Ontario, Canada
  • 2012
    • University of Michigan
      • Division of Metabolism, Endocrinology & Diabetes
      Ann Arbor, MI, United States
    • National Heart, Lung, and Blood Institute
      • Division of Cardiovascular Sciences (DCVS)
      Maryland, United States
    • Alpert Medical School - Brown University
      Providence, Rhode Island, United States
  • 2007–2012
    • University of California, San Diego
      • Division of Cardiology
      San Diego, CA, United States
  • 2010–2011
    • Hospital of the University of Pennsylvania
      • Department of Medicine
      Philadelphia, Pennsylvania, United States
  • 2002–2009
    • Johns Hopkins Bloomberg School of Public Health
      • Department of Epidemiology
      Baltimore, Maryland, United States
  • 2004
    • GE India Industrial Pvt. Ltd.
      New Dilli, NCT, India
  • 1996
    • University of Maryland, Baltimore
      • Division of Cardiology
      Baltimore, MD, United States