57 research outputs found
Coronary spiral CT
This dissertation describes the use and clinical potential of ECG gated multislice
spiral computed tomography in patients with coronary artery disease. First the
use of other non invasive cardiac imaging, i.e. the previously mentioned
electron beam CT and magnetic resonance imaging is reviewed (chapter 2.1).
Part 3 contains studies related to the characteristics of multislice spiral CT for
the imaging of the heart and coronary arteries, and the diagnostic potential of
ECG gated spiral CT coronary angiography to detect and visualize obstructive
coronary artery disease in symptomatic patients, using conventional coronary
angiography as the standard of reference. Part 4 is focussed on the feasibility
and characteristics of coronary wall imaging by CT, including the assessment of
non calcified atherosclerotic plaque material. The usefulness of
contrast enhanced multislice spiral CT in symptomatic patients who previously
underwent coronary artery bypass grafting and percutaneous coronary
intervention with stent implantation is discussed in part 5. Finally, the first results with the latest generation 16 slice computed tomography scanners and
patient preparation with ~ receptor blockers are described in part 6, including a
review and future outlook on the continuing development and clinical use of
non invasive coronary angiography with spiral computed tomography
Prognostic Value of Subclinical Coronary Artery Disease in Atrial Fibrillation Patients Identified by Coronary Computed Tomography Angiography
Identifying coronary artery disease (CAD) in atrial fibrillation (AF) patients improves risk stratification and defines clinical management. However, the value of screening for subclinical CAD with cardiac CT in AF patients is unknown. Between 2011 and 2015, 94 consecutive patients without known or suspected CAD (66 (57–73) years, 68% male), who were referred for AF evaluation, under
Non-invasive coronary angiography with multislice spiral computed tomography: impact of heart rate
OBJECTIVE: To evaluate the impact of heart rate on the diagnostic accuracy
of coronary angiography by multislice spiral computed tomography (MSCT).
DESIGN: Prospective observational study. PATIENTS: 78 patients who
underwent both conventional and MSCT coronary angiography for suspicion of
de novo coronary artery disease (n=53) or recurrent coronary artery
disease after percutaneous intervention (n=25). SETTING: Tertiary referral
centre. METHODS: Intravenously contrast enhanced MSCT coronary angiography
was done during a single breath hold, and ECG synchronised images were
reconstructed retrospectively. All coronary segments of > or = 2.0 mm
without stents were evaluated by two investigators and compared with
quantitative coronary angiography. Patients were classified according to
the average heart rate (mean (SD)) into three equally sized groups: group
1, 55.8 (4.1) beats/min; group 2, 66.6 (2.8) beats/min; group 3, 81.7
(8.8) beats/min. RESULTS: Image quality was sufficient for analysis in 78%
of the coronary segments in patients in group 1, 73% in group 2, and 54%
in group 3 (p < 0.01). The sensitivity and specificity for detecting
significant stenoses (> or = 50% lumen reduction) in these assessable
segments were: 97% (95% confidence interval (CI) 84% to 100%) and 96% in
group 1; 74% (52% to 89%) and 94% in group 2; and 67% (33% to 90%) and 94%
in group 3 (p or = 2.0 mm,
including lesions in non-assessable segments as false negatives, the
sensitivity decreased to 82% (28/34 lesions, 95% CI 69% to 91%), 61%
(14/23 lesions, 42% to 77%), and 32% (6/19 lesions, 15% to 50%),
respectively (p < 0.01). CONCLUSIONS: MSCT allows reliable coronary
angiography in patients with low heart rates
Diagnostic value of transmural perfusion ratio derived from dynamic CT-based myocardial perfusion imaging for the detection of haemodynamically relevant coronary artery stenosis
Objectives: To investigate the additional value of transmural perfusion ratio (TPR) in dynamic CT myocardial perfusion imaging for detection of haemodynamically significant coronary artery disease compared with fractional flow reserve (FFR). Methods: Subjects with suspected or known coronary artery disease were prospectively included and underwent a CT-MPI examination. From the CT-MPI time-point data absolute myocardial blood flow (MBF) values were temporally resolved using a hybrid deconvolution model. An absolute MBF value was measured in the suspected perfusion defect. TPR was defined as the ratio between the subendocardial and subepicardial MBF. TPR and MBF results were compared with invasive FFR using a threshold of 0.80. Results: Forty-three patients and 94 territories were analysed. The area under the receiver operator curve was larger for MBF (0.78) compared with TPR (0.65, P = 0.026). No significant differences were found in diagnostic classification between MBF and TPR with a territory-based accuracy of 77 % (67-86 %) for MBF compared with 70 % (60-81 %) for TPR. Combined MBF and TPR classification did not improve the diagnostic classification. Conclusions: Dynamic CT-MPI-based transmural perfusion ratio predicts haemodynamically significant coronary artery disease. However, diagnostic performance of dynamic CT-MPI-derived TPR is inferior to quantified MBF and has limited incremental value. Key Points: • The transmural perfusion ratio from dynamic CT-MPI predicts functional obstructive coronary artery disease• Performance of the transmural perfusion ratio is inferior to quantified myocardial blood flow• The incremental value of the transmural perfusion ratio is limite
Conventional hemodynamic resuscitation may fail to optimize tissue perfusion: An observational study on the effects of dobutamine, enoximone, and norepinephrine in patients with acute myocardial infarction complicated by cardiogenic shock
Aim: To investigate the effects of inotropic agents on parameters of tissue perfusion in patients with cardiogenic shock. Methods and Results: Thirty patients with cardiogenic shock were included. Patients received dobutamine, enoximone, or norepinephrine. We performed hemodynamic measurements at baseline and after titration of the inotropic agent until cardiac index (CI) ≥2.5 L.min-1.m-2 or mixed-venous oxygen saturation (SvO 2) ≥70% (dobutamine or enoximone), and mean arterial pressure (MAP) ≥70 mmHg (norepinephrine). As parameters of tissue perfusion, we measured central-peripheral temperature gradient (delta-T) and sublingual perfused capillary density (PCD). All patients reached predefined therapeutic targets. The inotropes did not significantly change delta-T. Dobutamine did not change PCD. Enoximone increased PCD (9.1 [8.9-10.2] vs. 11.4 [8.4-13.9] mm.mm-2; p10.3 mm.mm-2; mortality 72% vs. 17%, p = 0.003). Conclusion: This study demonstrates the effects of commonly used inotropic agents on parameters of tissue perfusion in patients with cardiogenic shock. Despite hemodynamic optimization, tissue perfusion was not sufficiently restored in most patients. In these patients, mortality was high. Interventions directed at improving microcirculation may eventually help bridging the gap between improved hemodynamics and dismal patient outcome in cardiogenic shock
HEART score improves efficiency of coronary computed tomography angiography in patients suspected of acute coronary syndrome in the emergency department
Aims: Coronary computed tomography angiography is increasingly employed in the emergency department for
suspected acute coronary syndrome patients. The HEART score has been proposed for initial risk stratification in these
patients. The aim of this study was to investigate the diagnostic value and efficiency of the HEART score before coronary
computed tomography angiography.
Methods and results: We included patients suspected of acute coronary syndrome who underwent coronary computed
tomography angiography in the emergency department. Based on the HEART score, patients were stratified as low-risk
(HEART≤3), intermediate-risk (HEART4–6) and high-risk (HEART≥7). We assessed coronary computed tomography
angiography for the presence of significant coronary artery disease (>50% stenosis). The primary outcome, the level of major
adverse cardiac events, was a composite endpoint of all-cause mortality, acute coronary syndrome or coronary revascularisation
within 30 days. The study population consisted of 340 patients (mean age: 55.6±10.1 years, 44.7% women), major adverse
cardiac events occurred in 45 (13.2%) patients. The incidence of major adverse cardiac events in patients stratified as low-risk
(35.0%), intermediate-risk (56.8%) and high-risk
Validation of 4D flow CMR against simultaneous invasive hemodynamic measurements: a swine study
The purpose of this study was to compare invasively measured aorta fow with 2D phase contrast fow and 4D fow measurements by cardiovascular magnetic resonance (CMR) imaging in a large animal model. Nine swine (mean weight 63±4 kg)
were included in the study. 4D fow CMR exams were performed on a 1.5T MRI scanner. Flow measurements were performed
on 4D fow images at the aortic valve level, in the ascending aorta, and main pulmonary artery. Simultaneously, fow was
measured using an invasive fow probe, placed around the ascending aorta. Additionally, standard 2D phase contrast fow
and 2D left ventricular (LV) volumetric data were used for comparison. The correlations of cardiac output (CO) between
the invasive fow probe, and CMR modalities were strong to very strong. CO measured by 4D fow CMR correlated better
with the CO measured by the invasive fow probe than 2D fow CMR fow and volumetric LV data (4D fow CMR: Spearman’s rho = 0.86 at the aortic valve level and 0.90 at the ascending aorta level; 2D fow CMR: 0.67 at aortic valve level; LV
measurements: 0.77). In addition, there tended to be a correlation between mean pulmonary artery fow and aorta fow with
4D fow (Spearman’s rho=0.65, P=0.07), which was absent in measurements obtained with 2D fow CMR (Spearman’s
rho=0.40, P=0.33). This study shows that aorta fow can be accurately measured by 4D fow CMR compared to simultaneously measured invasive fow. This helps to further validate the quantitative reliability of this technique
Impact of machine-learning CT-derived fractional flow reserve for the diagnosis and management of coronary artery disease in the randomized CRESCENT trials
Objective: To determine the potential impact of on-site CT-derived fractional flow reserve (CT-FFR) on the diagnostic efficiency and effectiveness of coronary CT angiography (CCTA) in patients with obstructive coronary artery disease (CAD) on CCTA. Methods: This observational cohort study included patients with suspected CAD who had been randomized to cardiac CT in the CRESCENT I and II trials. On-site CT-FFR was blindly performed in all patients with at least one ≥ 50% stenosis on CCTA and no exclusion criteria for CT-FFR. We retrospectively assessed the effect of adding CT-FFR to the CT protocol in patients with a stenosis ≥ 50% on CCTA in terms of diagnostic effectiveness, i.e., the number of additional tests required to determine the final diagnosis, reclassification of the initial management strategy, and invasive coronary angiography (ICA) efficiency, i.e., ICA rate without ≥ 50% CAD. Results: Fifty-three patients out of the 372 patients (14%) had at least one ≥ 50% stenosis on CCTA of whom 42/53 patients (79%) had no exclusion criteria for CT-FFR. CT-FFR showed a hemodynamically significant stenosis (≤ 0.80) in 27/53 patients (51%). The availability of CT-FFR would have reduced the number of patients requiring additional testing by 57%-points compared with CCTA alone (37/53 vs. 7/53, p < 0.001). The initial management strategy would have changed for 30 patients (57%, p < 0.001). Reserving ICA for patients with a CT-FFR ≤ 0.80 would have reduced the number of ICA following CCTA by 13%-points (p = 0.016). Conclusion: Implementation of on-site CT-FFR may change management and improve diagnostic efficiency and effectiveness in patients with obstructive CAD on CCTA. Key Points: • The availability of on-site CT-FFR in the diagnostic evaluation of patients with obstructive CAD on CCTA would have significantly reduced the number of patients requiring additional testing compared with CCTA alone. • The implementation of on-site CT-FFR would have changed the initial management strategy significantly in the patients with obstructive CAD on CCTA. • Restricting ICA to patients with a positive CT-FFR would have significantly reduced the ICA rate in patients with obstructive CAD on CCTA
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