Assessing the Role of Pericardial Fat as a Biomarker Connected to Coronary Calcification-A Deep Learning Based Approach Using Fully Automated Body Composition Analysis.

(1) Background: Epi- and Paracardial Adipose Tissue (EAT, PAT) have been spotlighted as important biomarkers in cardiological assessment in recent years. Since biomarker quantification is an increasingly important method for clinical use, we wanted to examine fully automated EAT and PAT quantification for possible use in cardiovascular risk stratification. (2) Methods: 966 patients with intermediate Framingham risk scores for Coronary Artery Disease referred for coronary calcium scans were included in clinical routine retrospectively. The Coronary Artery Calcium Score (CACS) was extracted and tissue quantification was performed by a deep learning network. (3) Results: The Computed Tomography (CT) segmentations predicted by the network indicated no significant correlation between EAT volume and EAT radiodensity when compared to Agatston score (r = 0.18, r = -0.09). CACS 0 category patients showed significantly lower levels of total EAT and PAT volumes and higher EAT and PAT densities than CACS 1-99 category patients (p < 0.01). Notably, this difference did not reach significance regarding EAT attenuation in male patients. Women older than 50 years, thus more likely to be postmenopausal, were shown to be at higher risk of coronary calcification (p < 0.01, OR = 4.59). CACS 1-99 vs. CACS ≥100 category patients remained below significance level (EAT volume: p = 0.087, EAT attenuation: p = 0.98). (4) Conclusions: Our study proves the feasibility of a fully automated adipose tissue analysis in clinical cardiac CT and confirms in a large clinical cohort that volume and attenuation of EAT and PAT are not correlated with CACS. Broadly available deep learning based rapid and reliable tissue quantification should thus be discussed as a method to assess this biomarker as a supplementary risk predictor in cardiac CT.

Right ventricular involvement in acute left ventricular myocardial infarction: prognostic implications of MRI findings.

OBJECTIVE: The purpose of this study was to investigate the prevalence and prognostic importance of the cardiac MRI finding of right ventricular involvement in patients with acute ST-segment elevation myocardial infarction (MI). SUBJECTS AND METHODS: Fifty patients (41 men, nine women; mean age, 58 +/- 11 years) with first-ST-segment elevation MI underwent 1.5-T cardiac MRI immediately after successful percutaneous coronary intervention. The cardiac MRI protocol included steady-state free precession cine sequences for functional assessment of the left, right, and both ventricles and inversion recovery FLASH delayed enhancement sequences after contrast administration for the quantification of myocardial damage. The prevalence of right ventricular involvement detected with ECG and echocardiography was compared with the prevalence detected with cardiac MRI, which was the reference standard. Patients underwent follow-up for 32 +/- 8 months. RESULTS: Right ventricular involvement was diagnosed with cardiac MRI in 27 patients (54%): 14 of 30 patients (47%) with inferior ST-segment elevation MI and 13 of 20 patients (65%) with anterior ST-segment elevation MI. ECG and echocardiographic findings showed only moderate agreement with cardiac MRI findings in the detection of right ventricular involvement in inferior acute MI (kappa = 0.38). Patients with right ventricular involvement in anterior ST-segment elevation MI had larger infarcts (delayed enhancement, 25.9% +/- 14.5% vs 11.4% +/- 10.1%; p = 0.030), lower left ventricular ejection fraction (34.3% +/- 8.2% vs 45.2% +/- 9.5%; p < 0.015), and lower right ventricular ejection fraction (39.8% +/- 6.6% vs 54.9% +/- 8.8%; p < 0.001) than those without right ventricular involvement. In a multivariate logistic regression model, right ventricular involvement was a strong independent predictor (odds ratio, 15.8; 95% CI, 4-63%) of major cardiac adverse events. CONCLUSION: Right ventricular involvement in ST-segment elevation MI is detected more frequently with cardiac MRI than with ECG and echocardiography and is an independent prognostic indicator.

Relation of B-type natriuretic peptide (BNP) and infarct size as assessed by contrast-enhanced MRI.

BACKGROUND: Plasma B-type natriuretic peptide (BNP) measured in acute coronary syndromes independently predicts mortality, myocardial infarction and congestive heart failure. OBJECTIVES: To investigate the relationship between the extent of delayed enhancement (DE) and microvascular obstruction (MO) in contrast-enhanced MRI and the plasma level of BNP in patients with acute myocardial infarction. METHODS: The study group consisted of 41 consecutive patients (26 males, mean age 57±11 years) with a first STEMI and complete reperfusion by primary PCI. EDTA-plasma samples were obtained 40±15 h after admission and analyzed for NT-pro-BNP. Cardiac MRI (CMR) was performed 50±29 h after coronary intervention on a 1.5 Tesla scanner. Cine images were acquired in contiguous short-axis views using a segmented steady-state free precession (SSFP) sequence (TR, 3 ms; TE, 1.5 ms; FA, 60°). Additionally, contrast-enhanced imaging was performed using a single shot steady-state free precession (IR-SSFP) sequence with an inversion recovery prepulse (TR, 2.4 ms; TE, 1.1 ms; FA, 50°; TI, 180 to 260 ms). RESULTS: Strong correlations between NT-pro-BNT plasma levels and delayed enhancement extent (r=0.74, p<0.001) as well as MO (r=0.7, p<0.001) were observed. The correlation between LVEF and plasma levels of BNP, however, was only moderate (r=-0.44, p=0.002). In a multiple linear regression model, DE remains the only parameter with an independent linear association with BNP. CONCLUSION: NT-pro-BNP, a surrogate biomarker for prognosis after STEMI, is closely associated with myocardial damage as assessed by contrast-enhanced CMR.

Assessment of left ventricular function and mass in dual-source computed tomography coronary angiography: influence of beta-blockers on left ventricular function: comparison to magnetic resonance imaging.

PURPOSE: To quantify left ventricular (LV) function and mass (LVM) derived from dual-source computed tomography (DSCT) and the influence of beta-blocker administration compared to cardiac magnetic resonance imaging (CMR). METHODS: Thirty-two patients undergoing cardiac DSCT and CMR were included, where of fifteen received metoprolol intravenously before DSCT. LV parameters were calculated by the disc-summation method (DSM) and by a segmented region-growing algorithm (RGA). All data sets were analyzed by two blinded observers. Interobserver agreement was tested by the intraclass correlation coefficient. RESULTS.: 1. Using DSM LV parameters were not statistically different between DSCT and CMR in all patients (DSCT vs. CMR: EF 63+/-8% vs. 64+/-8%, p=0.47; EDV 136+/-36 ml vs. 138+/-35 ml, p=0.66; ESV 52+/-21 ml vs. 52+/-22 ml, p=0.61; SV 83+/-22 ml vs. 87+/-19 ml, p=0.22; CO 5.4+/-0.9l/min vs. 5.7+/-1.2l/min, p=0.09, LVM 132+/-33 g vs. 132+/-33 g, p=0.99). 2. In a subgroup of 15 patients beta-blockade prior to DSCT resulted in a lower ejection fraction (EF), stroke volume (SV), cardiac output (CO) and increase in end systolic volume (ESV) in DSCT (EF 59+/-8% vs. 62+/-9%; SV 73+/-17 ml vs. 81+/-15 ml; CO 5.7+/-1.2l/min vs. 5.0+/-0.8 l/min; ESV 52+/-27 ml vs. 57+/-24 ml, all p<0.05). 3. Analyzing the RGA parameters LV volumes were not significantly different compared to DSM, whereas LVM was higher using RGA (177+/-31 g vs. 132+/-33 g, p<0.05). Interobserver agreement was excellent comparing DSM values with best agreement between RGA calculations. CONCLUSION: Left ventricular volumes and mass can reliably be assessed by DSCT compared to CMR. However, beta-blocker administration leads to statistically significant reduced EF, SV and CO, whereas ESV significantly increases. DSCT RGA reliably analyzes LV function, whereas LVM is overestimated compared to DSM.

Prognostic impact of contrast-enhanced CMR early after acute ST segment elevation myocardial infarction (STEMI) in a regional STEMI network: results of the "Herzinfarktverbund Essen".

BACKGROUND AND PURPOSE: In acute ST segment elevation myocardial infarction (STEMI), rapid restoration of epicardial coronary blood flow and myocardial perfusion limits infarct size and improves survival. Primary percutaneous coronary intervention (PCI) is superior to systemic fibrinolysis when instantly performed by experienced operators. The "Herzinfarktverbund Essen" (HIVE) is an urban STEMI network supporting direct patient transfer for primary PCI to four PCI centers covering a city area of 600,000 inhabitants. Integrated health care is an optional part of the HIVE allowing for reimbursement of medical innovations such as the evaluation of infarct size and the presence and extent of microvascular obstruction by contrast-enhanced cardiac magnetic resonance (CMR). The aim of this study was to assess the prognostic impact of contrast-enhanced CMR in the patient cohort of a regional STEMI network. PATIENTS AND METHODS: Within the 1st year (09/2004 to 08/2005) of the HIVE registry, 489 patients with acute myocardial infarction were treated in the four primary PCI centers. In one of the centers, including 143 patients, early CMR imaging using a standardized MR protocol for infarct quantification was performed whenever possible. Patients with hemodynamic instability, emergency coronary artery bypass grafting, resuscitation or death prior to CMR, claustrophobia, and other general contraindications to MRI had to be excluded, leaving 67 patients (54 male; mean age 61 +/- 12 years) for final evaluation. CMR was performed 4.5 +/- 2.5 days after admission on a 1.5-T MR scanner (Sonata, Siemens Medical Solutions, Erlangen, Germany) including steady-state free precession (SSFP) cine imaging for left ventricular function and single-shot inversion-recovery SSFP imaging for delayed enhancement (DE) and no-reflow (NR) evaluation following injection of 0.2 mmol/kg body weight gadodiamide (Omniscan, GE Healthcare Buchler, Munich, Germany). NR and DE volumes were calculated from single-shot short-axis stacks taken within the 1st minute following gadodiamide infusion by manual planimetry and summation of disks. 1-year follow-up data (telephone interview) for major adverse cardiac events (MACE: cardiac death, myocardial infarction, and rehospitalization for congestive heart failure, angina pectoris, or revascularization) were available for all patients. RESULTS: DE as a measure of infarct size was 9% +/- 7% (range 0-33%) of left ventricular mass (LVM), and mean volume of microvascular obstruction was 2% +/- 3% (range 0-17%). Microvascular obstruction was present in 61% of patients. 16 MACE (one cardiac death, one myocardial infarction, and 14 rehospitalizations for congestive heart failure or unstable angina pectoris with PCI in six cases) occurred within the follow-up period of 430 +/- 63 days. Patients with MACE had larger infarcts (14% +/- 10% vs. 8% +/- 6% DE), lower left ventricular ejection fraction (LVEF 44% +/- 17% vs. 48% +/- 14%) and larger NR (3% +/- 5% vs. 2% +/- 3%). Using a stepwise logistic regression model, only NR > 0.5% of LVM was independently related to outcome (odds ratio = 3.9, confidence interval 1.1-13.9). CONCLUSION: NR as a correlate of microvascular obstruction remains independently related to prognosis in patients with acute myocardial infarction treated by PCI.

Quantification of aortic valve stenosis in MRI-comparison of steady-state free precession and fast low-angle shot sequences.

We compared two different magnetic resonance (MR) sequences [steady-state free precession (SSFP) and gradient echo fast low-angle shot (FLASH)] for the assessment of aortic valve areas in aortic stenosis using transesophageal echocardiography (TEE) as the standard of reference. Thirty-two patients with known aortic stenosis underwent MR (1.5 T) using a cine SSFP sequence and a cine FLASH sequence. Planimetry was performed in cross-sectional images and compared to the results of the TEE. In seven patients the grade of stenosis was additionally assessed by invasive cardiac catheterization (ICC). The mean aortic valve area measured by TEE was 0.97+/-0.19 mm(2), 1.00+/-0.25 mm(2) for SSFP and 1.25+/-0.23 mm(2) based on FLASH images. The mean difference between the valve areas assessed based on SSFP and TEE images was 0.15+/-0.13 cm(2) (FLASH vs TEE: 0.29+/-0.17 cm(2)). Bland-Altman analysis demonstrated that measurements using FLASH images overestimated the aortic valve area compared to TEE. Comparing ICC with MRI and TEE, only a weak to moderate correlation was found (ICC vs TEE: R=0.52, p=0.22; ICC vs SSFP: R=0.20, p=0.65; ICC vs FLASH: R=0.16, p=0.70). Measurements of the aortic valve area based on SSFP images correlate better with TEE compared to FLASH images.

Imaging of myocardial perfusion with magnetic resonance.

Coronary artery disease (CAD) is currently the leading cause of death in developed nations. Reflecting the complexity of cardiac function and morphology, noninvasive diagnosis of CAD represents a major challenge for medical imaging. Although coronary artery stenoses can be depicted with magnetic resonance (MR) and computed tomography (CT) techniques, its functional or hemodynamic impact frequently remains elusive. Therefore, there is growing interest in other, target organ-specific parameters such as myocardial function at stress and first-pass myocardial perfusion imaging to assess myocardial blood flow. This review explores the pathophysiologic background, recent technical developments, and current clinical status of first-pass MR imaging (MRI) of myocardial perfusion.