Sixty-four-slice multidetector computed tomography for preoperative evaluation of left ventricular function and mass in patients with mitral regurgitation: comparison with magnetic resonance imaging and echocardiography

Cardiac chamber volumes and left ventricular mass in people living with HIV and matched uninfected controls

OBJECTIVES

People living with HIV (PLWH) have increased risk of cardiovascular diseases compared with uninfected populations. We assessed structural cardiac abnormalities and their associated risk factors in well-treated PLWH and uninfected controls using multidetector computed tomography (MDCT).

METHODS

People living with HIV and age- and sex-matched uninfected controls underwent MDCT to determine left atrial volume (LAV), left ventricular diastolic volume (LVDV), right ventricular diastolic volume (RVDV) and left ventricular mass (LVM). All outcomes were indexed to body surface area (BSA) (LAVi, LVDVi, RVDVi and LVMi).

RESULTS

A total of 592 PLWH and 1184 uninfected controls were included in the study. PLWH had smaller mean (SD) LAVi [40 (8) vs. 41 (9) mL/m² ; P = 0.002] and LVDVi [61 (13) vs. 65 (14) mL/m² ; P < 0.001] but larger RVDVi [89 (18) vs. 86 (17) mL/m² ; P < 0.001] than uninfected controls. HIV was independently associated with 7 mL (95% CI: -10 to -3) smaller LVDV, and with 12 mL (95% CI: 8-16) larger RVDV, and 4 g (95% CI: 1-6) larger LVM after adjustment for cardiovascular risk factors and BSA. Large RVDV in PLWH was not associated with obstructive lung function.

CONCLUSIONS

HIV was independently associated with smaller LVDV and larger RVDV and LVM. Alterations in cardiac chamber volumes in PLWH were mainly minor. The clinical impact of these findings is uncertain, but it seems unlikely that alterations in cardiac chamber volumes explain the increased burden of cardiovascular disease previously observed in PLWH.

Protective effect of glucagon-like peptide-1 agents on reperfusion injury for acute myocardial infarction: a meta-analysis of randomized controlled trials

BACKGROUND

The cardioprotective properties of glucagon-like peptide-1 (GLP-1) receptor agonists in acute myocardial infarction (AMI) patients against reperfusion injury remain unclear. We performed a meta-analysis to assess their role in the acute phase of AMI.

METHODS AND RESULTS

Randomized controlled trials (RCTs) comparing GLP-1 agents with placebo in AMI patients undergoing percutaneous coronary intervention were identified by searching PubMed, Embase and Cochrane libraries. Six RCTs with 800 patients were included in the meta-analysis. Compared with placebo, GLP-1 agents improved left ventricular ejection fraction (LVEF) by 2.46 [95% confidence interval (CI): 0.23-4.70%] and reduced the infarct size in grams as well as in percentage of the area at risk [weighted mean difference (WMD) - 5.29, 95% CI: -10.39 to -0.19; WMD -0.08, 95% CI: -0.12 to -0.04, respectively]. The incidence of cardiovascular events appeared to be lower with GLP-1 therapy, but the statistical significance was not reached [relative risk (RR): 0.78; 95% CI: 0.58-1.06]. In terms of safety evaluation, GLP-1 treatment increased the risk of gastrointestinal adverse events (RR: 5.50, 95% CI: 2.85-10.60).

CONCLUSIONS

Our analysis shows that in patients with AMI undergoing PCI, GLP-1 treatment is associated with improved LVEF and reduced infarct size.

Cardiac Computed Tomography and Magnetic Resonance Imaging in the Evaluation of Mitral and Tricuspid Valve Disease

Transcatheter interventions to treat mitral and tricuspid valve disease are becoming increasingly available because of the growing number of elderly patients with significant comorbidities or high operative risk. Thorough clinical and imaging evaluation in these patients is essential. The latter involves both characterization of the mechanism and severity of valvular disease as well as determining the hemodynamic consequences and extent of ventricular remodeling, which is an important predictor of future outcomes. Moreover, an assessment of the suitability and risk of complications associated with device-specific therapies is also an important component of the preprocedural evaluation in this cohort. Although echocardiography including 2-dimensional and 3-dimensional methods has an important role in the initial assessment and procedural guidance, cross-sectional imaging, including both computed tomographic imagning and cardiac magnetic resonance imaging, is increasingly being integrated into the evaluation of mitral and tricuspid valve disease. In this review, we discuss the role of cross-sectional imaging in mitral and tricuspid valve disease, primarily valvular regurgitation assessment, with an emphasis on the preprocedural evaluation and implications for transcatheter interventions.

Korean guidelines for the appropriate use of cardiac CT

The development of cardiac CT has provided a non-invasive alternative to echocardiography, exercise electrocardiogram, and invasive angiography and cardiac CT continues to develop at an exponential speed even now. The appropriate use of cardiac CT may lead to improvements in the medical performances of physicians and can reduce medical costs which eventually contribute to better public health. However, until now, there has been no guideline regarding the appropriate use of cardiac CT in Korea. We intend to provide guidelines for the appropriate use of cardiac CT in heart diseases based on scientific data. The purpose of this guideline is to assist clinicians and other health professionals in the use of cardiac CT for diagnosis and treatment of heart diseases, especially in patients at high risk or suspected of heart disease.

Computed Tomography for Structural Heart Disease and Interventions

Transcatheter cardiac interventions are a fast evolving field. The past decade has seen the development of transcatheter aortic valve replacement, transcatheter mitral valve repair and replacement, septal defect closure devices and left atrial appendage closure devices for thromboprophylaxis. More than ever, medical imaging is taking a central role in the care of patients with structural heart disease. In this review article we outline the use of MSCT as a tool for diagnosis of structural heart interventions, as well as patient selection, pre-procedural planning, device sizing and post-procedural assessment. We focus on procedures targeting the aortic valve, the mitral valve, the inter-atrial septum and the left atrial appendage.

Meta-analysis of global left ventricular function comparing multidetector computed tomography with cardiac magnetic resonance imaging

We compare the diagnostic accuracy of multidetector row computed tomography (MDCT) to cardiac magnetic resonance imaging (CMR) for evaluating global left ventricular function. We systematically searched PubMed, CINAHL, Cochrane CENTRAL, Scopus, and the Web of Science databases for studies published between 1966 to January 2013 that compared left ventricle (LV) volumes, ejection fraction (EF) and LV mass measured by MDCT and CMR. We performed meta-analyses and used random-effects model with inverse variance weighting test to determine the overall bias and limits of agreement of LV end-diastolic volume, end-systolic volume, stroke volume, and EF measured by MDCT and CMR. Furthermore, subgroup analyses were performed to compare 16-slice and 64-slice MDCT with CMR. Two study authors independently reviewed the 90 articles originally identified and selected 27 studies (n = 831) for analysis. Excellent correlation and a linear relation were seen between MDCT and CMR for LV end-diastolic volume (r = 0.93; p <0.001), LV end-systolic volume (r = 0.95; p <0.001), LV stroke volume (r = 0.85; p <0.001), LV ejection fraction (r = 0.93; p <0.001), and LV mass (r = 0.86; p <0.001). Subgroup analyses showed strong positive correlations for both 16- and 64-slice MDCT. In conclusion, although not the first-line test for LV function assessment in most patients, when appropriate, retrospectively gated MDCT provides an accurate and valid assessment of LV function compared with CMR.

Head-to-head comparison of left ventricular function assessment with 64-row computed tomography, biplane left cineventriculography, and both 2- and 3-dimensional transthoracic echocardiography: comparison with magnetic resonance imaging as the reference standard

OBJECTIVES

This study was designed to compare the accuracy of 64-row contrast computed tomography (CT), invasive cineventriculography (CVG), 2-dimensional echocardiography (2D Echo), and 3-dimensional echocardiography (3D Echo) for left ventricular (LV) function assessment with magnetic resonance imaging (MRI).

BACKGROUND

Cardiac function is an important determinant of therapy and is a major predictor for long-term survival in patients with coronary artery disease. A number of methods are available for assessment of function, but there are limited data on the comparison between these multiple methods in the same patients.

METHODS

A total of 36 patients prospectively underwent 64-row CT, CVG, 2D Echo, 3D Echo, and MRI (as the reference standard). Global and regional LV wall motion and ejection fraction (EF) were measured. In addition, assessment of interobserver agreement was performed.

RESULTS

For the global EF, Bland-Altman analysis showed significantly higher agreement between CT and MRI (p < 0.005, 95% confidence interval: ±14.2%) than for CVG (±20.2%) and 3D Echo (±21.2%). Only CVG (59.5 ± 13.9%, p = 0.03) significantly overestimated EF in comparison with MRI (55.6 ± 16.0%). CT showed significantly better agreement for stroke volume than 2D Echo, 3D Echo, and CVG. In comparison with MRI, CVG-but not CT-significantly overestimated the end-diastolic volume (p < 0.001), whereas 2D Echo and 3D Echo significantly underestimated the EDV (p < 0.05). There was no significant difference in diagnostic accuracy (range: 76% to 88%) for regional LV function assessment between the 4 methods when compared with MRI. Interobserver agreement for EF showed high intraclass correlation for 64-row CT, MRI, 2D Echo, and 3D Echo (intraclass correlation coefficient >0.8), whereas agreement was lower for CVG (intraclass correlation coefficient = 0.58).

CONCLUSIONS

64-row CT may be more accurate than CVG, 2D Echo, and 3D Echo in comparison with MRI as the reference standard for assessment of global LV function.

Coronary CT and the coronary calcium score, the future of ED risk stratification?

Accurate and efficient evaluation of acute chest pain remains clinically challenging because traditional diagnostic modalities have many limitations. Recent improvement in non-invasive imaging technologies could potentially improve both diagnostic efficiency and clinical outcomes of patients with acute chest pain while reducing unnecessary hospitalizations. However, there is still controversy regarding much of the evidence for these technologies. This article reviews the role of coronary artery calcium score and the coronary computed tomography in the assessment of individual coronary risk and their usefulness in the emergency department in facilitating appropriate disposition decisions. The evidence base and clinical applications for both techniques are also described, together with cost- effectiveness and radiation exposure considerations.

Accuracy of multi-slice computed tomography for measurement of left ventricular ejection fraction compared with cardiac magnetic resonance imaging and two-dimensional transthoracic echocardiography: a systematic review and meta-analysis

BACKGROUND

Multi-slice computed tomography (MSCT) allows non-invasive assessment of the coronary arteries and simultaneously can provide measurement of left ventricular ejection fraction (LVEF). The accuracy of newer MSCT generations (64-slice or more) for assessment of LVEF compared with magnetic resonance imaging (MRI) and two-dimensional transthoracic echocardiography (TTE) has not been evaluated in a meta-analysis.

PURPOSE

To evaluate, via a systematic literature review and meta-analysis, whether MSCT can assess LVEF with high accuracy compared with MRI and TTE.

METHODS

Electronic databases and reference lists for relevant published studies were searched. Twenty-seven eligible studies provided mean LVEF% with its standard deviation (SD) measured by MSCT versus MRI and TTE. Meta-analysis of weighted mean difference (WMD) and Bland-Altman method were used to quantify the mean difference and agreement between MSCT compared with MRI and TTE.

RESULTS

The results of combining 12 studies showed no significant difference in LVEF% between MSCT and MRI with a WMD of -0.11 (-1.48, 1.26, 95% CI), p=0.88. Bland-Altman analysis showed excellent agreement between MSCT and MRI with a bias of 0.0 (-3.7, 3.7 ± 1.96SD) with 95% CI. The results of combining 15 studies showed no significant difference in LVEF between MSCT versus TTE measurements with a WMD of 0.19 (-1.13 to 1.50; 95% CI), p=0.87. Bland-Altman analysis showed excellent agreement between MSCT and TTE with a bias of 0.3 (-4.7, 5.7 ± 1.96SD) with 95% CI.

CONCLUSION

The newer MSCT generations can provide accurate LVEF measurement compared to MRI and TTE. MSCT represents a valid technique for the combined evaluation of LVEF and coronary artery disease.

Relation of left ventricular mass and concentric remodeling to extent of coronary artery disease by computed tomography in patients without left ventricular hypertrophy: ROMICAT study

OBJECTIVE

Cardiac computed tomography allows for simultaneous assessment of left ventricular mass (LVM) and coronary artery disease (CAD). We aimed to determine whether LVM, LVM index (LVMi), and the left ventricular geometric pattern of concentric remodeling are associated with the extent of CAD in patients without left ventricular hypertrophy.

METHODS

In 348 patients from the Rule Out Myocardial Infarction Using Computer Assisted Tomography trial, 64-slice computed tomography was performed and LVM measured at end-diastole. We used three LVM indexation criteria to obtain three cohorts: LVM indexed to body surface area by echocardiography (n = 337) and computed tomography criteria (n = 325), and by height (n = 326). The cohorts were subdivided into concentric remodeling and normal geometry. Extent of coronary plaque was classified based on a 17-segment model, treated as a continuous variable, and stratified into three groups: zero segment, one to four segments, and more than four segments.

RESULTS

Patients with more than four segments of coronary plaque had higher LVM (Delta12.8-15.1 g) and LVMi (Delta4.0-5.5 g/m and Delta2.2 g/m) than those without CAD (all P < or = 0.03). After multivariable adjustment, LVM and LVMi remained independent predictors of extent of coronary plaque, with 0.27-0.29 segments more plaque per 20 g increase of LVM (all P = 0.02), 0.32-0.34 segments more plaque per 10 g/m increase of LVMi (both P = 0.02), and 0.80 segments more plaque per 10 g/m increase of LVMi (P = 0.008). Concentric remodeling patients had 1.1-1.3 segments more plaque than those with normal geometry (all P < or = 0.05). Patients with more than four segments of plaque had two-fold increase in odds (all P < or = 0.05) of having concentric remodeling as compared with those without CAD.

CONCLUSION

Increased LVM, LVMi, and concentric remodeling are associated with a greater degree of coronary plaque burden in patients without left ventricular hypertrophy. These findings could provide an indication to intensify medical therapy in patients with subclinical CAD and hypertension.