Δευτέρα 18 Νοεμβρίου 2019

Diagnosis of coronary artery disease in patients with atrial fibrillation using low tube voltage coronary CT angiography with isotonic low-concentration contrast agent

Abstract

This prospective study evaluated the image quality and accuracy of coronary computed tomography angiography (CCTA) for diagnosing coronary artery disease (CAD) in patients with atrial fibrillation (AF), in which CCTA used adaptive iterative dose reduction (AIDR) with a low tube voltage and low concentration of isotonic contrast agent. Sixty-eight consecutive patients with AF and suspected CAD were equally and randomly apportioned to two groups and underwent CCTA. In the experimental group, the contrast agent was iodixanol (270 mg I/mL), patients were scanned with 100 kV, and reconstruction was by AIDR. In the conventional scanning (control) group, the contrast agent was iopromide (370 mg I/mL), patients were scanned with 120 kV, and reconstruction was by filtered back projection. The image quality, effective radiation dose (E), and total iodine intake of the groups were compared. Thirty-nine patients with coronary artery stenosis later were given invasive coronary angiography (ICA). The groups were similar with regard to mean CT value, noise, and signal-to-noise and contrast-to-noise ratios. The figure of merit of the experimental group was significantly higher than that of the control group, while the E and total iodine were significantly lower. Using ICA as the diagnostic reference, the groups shared similar sensitivity, specificity, and false positive and false negative rates for diagnosing coronary artery stenosis. For determining CAD in patients with AF, CCTA with isotonic low-concentration contrast agent and low-voltage scanning is a feasible alternative that improves accuracy and reduces radiation dose and iodine intake.

Denoising and artefact removal for transthoracic echocardiographic imaging in congenital heart disease: utility of diagnosis specific deep learning algorithms

Abstract

Deep learning (DL) algorithms are increasingly used in cardiac imaging. We aimed to investigate the utility of DL algorithms in de-noising transthoracic echocardiographic images and removing acoustic shadowing artefacts specifically in patients with congenital heart disease (CHD). In addition, the performance of DL algorithms trained on CHD samples was compared to models trained entirely on structurally normal hearts. Deep neural network based autoencoders were built for denoising and removal of acoustic shadowing artefacts based on routine echocardiographic apical 4-chamber views and performance was assessed by visual assessment and quantifying cross entropy. 267 subjects (94 TGA and atrial switch and 39 with ccTGA, 10 Ebstein anomaly, 9 with uncorrected AVSD and 115 normal controls; 56.9% male, age 38.9 ± 15.6 years) with routine transthoracic examinations were included. The autoencoders significantly enhanced image quality across diagnostic subgroups (p < 0.005 for all). Models trained on congenital heart samples performed significantly better when exposed to examples from congenital heart disease patients. Our study demonstrates the potential of autoencoders for denoising and artefact removal in patients with congenital heart disease and structurally normal hearts. While models trained entirely on samples from structurally normal hearts perform reasonably in CHD, our data illustrates the value of dedicated image augmentation systems trained specifically on CHD samples.

Novel mesh-derived right ventricular free wall longitudinal strain analysis by intraoperative three-dimensional transoesophageal speckle-tracking echocardiography: a comparison with conventional parameters

Abstract

Longitudinal right ventricular (RV) function is substantial and might be reflected by free wall longitudinal strain (FWLS). Software solutions for FWLS analysis by two-dimensional (2D) and three-dimensional (3D) transesophageal echocardiography (TEE) are available, but data on validation are sparse. In this study, a novel method for FWLS analysis on 3D meshes (“mesh surface”, MS-FWLS,) was tested for feasibility and compared to available parameters. 80 patients undergoing left-sided cardiac valve surgery with intraoperative TEE were included retrospectively. 2D-FWLS, 3D-derived (3Dd)-FWLS (assessed in optimized four-chamber views after volume analysis) and MS-FWLS were measured and compared to conventional parameters (3Dd-TAPSE, FAC and RVEF). The mean FWLS values did not differ significantly between methods (− 19.0 ± 6.1%, − 20.0 ± 7.3%, − 19.5 ± 7.3% for 2D-, 3Dd- and MS-FWLS, respectively). No significant differences in the mean FWLS between patients with normal or increased pulmonary artery pressures as well as normal or reduced left ventricular ejection fraction were observed. Agreement was best between 3Dd- and MS-FWLS (r = 0.89, bias = − 1.0%, LOA ± 6.9%). Conventional echocardiographic parameters yielded poorer intermodality agreement. In patients with discrepant results between 2D- and 3Dd-FWLS, 3Dd-FWLS and MS-FWLS yielded similar results (r = 0.82, bias = − 0.3%, LOA ± 8.6%), while 2D-FWLS and MS-FWLS did not. Intra- and interobserver variabilities of strain analyses were low. MS-FWLS might represent a promising method to overcome artefacts associated with 2D analysis. Its prognostic relevance needs to be investigated in prospective studies.

Evaluation of left atrial volume and function in patients with coronary slow flow phenomenon using real-time three-dimensional echocardiography

Abstract

This study aimed to evaluate the left atrial (LA) volume and phasic functions using real-time three-dimensional echocardiography (RT3DE) in coronary slow flow phenomenon (CSFP) patients with preserved left ventricular ejection fraction (LVEF). 56 patients with CSFP (36 males, 20 females) and 48 controls with normal coronary flow (27 males, 21 females) were prospectively enrolled. Comprehensive transthoracic echocardiographic examination and RT3DE for the assessment of LA dynamics were performed in all participants. LA maximum, minimum, and pre-atrial contraction volumes (LAV-max, LAV-min, and LAV-preA) were obtained for every subject. Conventional echocardiographic parameters, except for isovolumetric relaxation time and transmitral deceleration time, did not differ in two groups. RT3DE demonstrated higher LAV-max, LAV-min, LAV-preA, indexed LAV-max (LAVi-max), LA total emptying volume, and LA active emptying volume and fraction for CSFP patients compared with controls (all P < 0.05). In addition, LA total emptying fraction and LA passive emptying fraction were found to be lower in CSFP patients than in controls (all P < 0.05). Moreover, there were positive correlations between mean thrombolysis in myocardial infarction frame count values and LAV-max, LAV-min, LAV-preA, LAVi-max, and LA total and active emptying volumes. CSFP was associated with enlarged LA volumes, impaired LA reservoir and conduit function and enhanced contractile function. Evaluation of LA dynamics using RT3DE could facilitate recognition of subtle myocardial alterations related with CSFP.

Patients with high left ventricular filling pressure may be missed applying 2016 echo guidelines: a pilot study

Abstract

2016 guidelines for the echographic evaluation of left ventricular filling pressure (LVFP) proposed a single algorithm with limited number of criteria (E/A ratio, tricuspid regurgitation velocity, left atrial volume index and average E/e′) mainly related to left atrial pressure. Pulmonary venous flow analysis, evaluating more specifically left ventricular end diastolic pressure (LVEDP) has been withdrawn. We aim to evaluate the proportion of patients diagnosed with normal LVFP according to 2016 recommendations, despite an abnormal pulmonary venous flow profile suggesting high LVEDP. We prospectively studied patients with stable ischemic cardiomyopathy and aortic stenosis, before cardiac surgery. Extensive echocardiography was performed including pulmonary and mitral A wave durations. We included 76 patients (mean age 72 ± 10 years, 78% were men), 37 (49%) with aortic stenosis and 22 (29%) with ischemic cardiomyopathy. Mean left ventricular ejection fraction was 67 ± 11%. Applying recommendations, 58 patients had normal LVFP and 15 patients had high LVFP. Among the 58 patients with normal LVFP, 26 patients had Apd–Amd duration > 30 ms highly suggestive of high LVEDP. These patients had higher LV mass (112 ± 30 g/m2 vs. 86 ± 20 g/m2, p = 0.004) and shorter A wave duration (120 ± 13.6 ms vs. 132 ± 16.5 ms, p = 0.006) as compared to the remaining 15 patients with concordant evaluation (normal LVFP and normal Apd–Amd). In the present study, we found that 26/58 patients with low LVFP according to the 2016 recommendations had Apd–Amd suggestive of high LVEDP. Pulmonary venous flow should be added to the algorithm, particularly in patients with unexplained symptom, high LV mass or truncated mitral A wave.

Diagnostic and prognostic value of cardiac magnetic resonance in acute myocarditis: a systematic review and meta-analysis

Abstract

While diagnostic criteria were elaborated for acute myocarditis using cardiac magnetic resonance (CMR) in 2009, studies have since examined the yield of traditional and novel CMR parameters to achieve greater accuracy and to predict clinical outcomes. The purpose of this systematic review and meta-analysis was to determine the diagnostic and prognostic value of CMR parameters for acute myocarditis. MEDLINE and EMBASE were systematically searched for original studies that reported CMR parameters in adult patients suspected of acute myocarditis. Each CMR parameter's binary prevalence, mean value and standard deviation were extracted. Parameters were meta-analyzed using a random-effects model to generate standardized mean differences. After screening 1492 abstracts, 53 studies were included encompassing 2823 myocarditis patients and 803 controls. Pooled standardized mean differences between myocarditis patients and controls were: T2 mapping time 2.26 (95% CI 1.50–3.02), extracellular volume 1.64 (95% CI 0.87–2.42), LGE percentage 1.30 (95% CI 0.95–1.64), T1 mapping time 1.18 (95% CI 0.35–2.01), T2 ratio 1.17 (95% CI 0.80–1.54), and EGE ratio 0.93 (95% CI 0.66–1.19). Prolonged T1 mapping time had the highest sensitivity (82%), pericardial effusion had the highest specificity (99%). Baseline LV dysfunction and the presence of LGE were predictive of major adverse cardiac events. The results support integration of parametric mapping criteria in the diagnostic criteria for myocarditis. The presence of baseline LV dysfunction and LGE predict patients at higher risk of adverse events.

Impact of lesion angle on optical coherence tomography findings and clinical outcomes after drug-eluting stent implantation in curved vessels

Abstract

Tortuous coronary lesions are associated with adverse outcomes after implantation of bare metal or first-generation drug-eluting stents (DESs). We investigated the impact of lesion angle on vessel wall injuries and stent apposition as assessed by optical coherence tomography (OCT) after second- and newer-generation DES implantation. We investigated 95 de novo lesions treated with a single DES (62 platinum-chromium everolimus-eluting stents and 33 bioresorbable-polymer sirolimus-eluting stents). Post-intervention OCT findings were compared between angled lesions (≥ 45°; n = 33) and non-angled lesions (< 45°; n = 62). The 12-month clinical outcomes were also compared between the groups. Cross-sectional OCT analysis revealed that compared to non-angled lesions, angled ones had a significantly higher incidence of intra-stent dissection around the centre of the angle (19.7% vs. 10.8%, p = 0.01) and incomplete stent apposition (ISA) in the distal and proximal sub-segments (10.0% vs. 4.1%, p = 0.002; 15.3% vs. 7.9%, p < 0.001, respectively). Strut-based analysis also showed that angled lesions demonstrated a higher rate of malapposed strut in the distal and proximal sub-segments (3.0% vs. 0.9%, p < 0.001; 4.3% vs. 1.8%, p < 0.001, respectively). The 12 month clinical outcomes were comparable between the groups. Compared to non-angled lesions, angled coronary lesions were associated with a higher incidence of intra-stent dissection and ISA on post-intervention OCT after implantation of second- and newer-generation DESs.

Impact of two formulas to calculate percentage diameter stenosis of coronary lesions: from stenosis models (phantom lesion model) to actual clinical lesions

Abstract

Percentage diameter stenosis (%DS) by angiography is still commonly used to determine luminal obstruction of coronary artery disease (CAD) lesions. While visual estimation of %DS is widespread, because of high inter-operator variability, quantitative coronary arteriography (QCA) analysis is the gold standard. There are two %DS formulas: %DS1 averages the proximal and distal reference vessel diameter (RVD); %DS2 interpolates the RVD. This study aims to evaluate the difference between %DS assessed by QCA in two datasets, phantom lesion models and CAD patients. Ten phantom lesion models (PLMs) and 354 CAD lesions from the FIRST trial were assessed by QCA. In the latter, two scenarios were assessed: Scenario A (worst view), the most common approach in the clinical setting; and Scenario B (average of two complementary views), the standard core-laboratory analysis. In the PLMs, %DS1 and %DS2 mean ± standard deviation (median) was 58.5 ± 21.7 (61.6) and 58.7 ± 21.6 (61.8), respectively, with a signed difference of − 0.2% ± 0.3% (− 0.1%). In Scenario A, the mean %DS1 was 43.8 ± 9.1 (43.3) and 44.0 ± 9.1 (42 .9) in %DS2. In Scenario B, the mean %DS1 was 45.3 ± 8.8 (45.1) and 45.5 ± 9.0 (45.1) in %DS2. The signed difference was − 0.2% ± 2.4% (0.0%) and − 0.2% ± 2.1% (0.0%) in Scenario A and B, respectively. These differences between formulas ranged from − 1.2 to 0.5% for the phantom cases compared to − 17.7% to 7.7% in Scenario A and to − 15.5% to 7.1% in Scenario B. Although the overall means of the formulas provide similar results, significant lesion-level differences are observed. The use of the worst view versus the average of two views provided similar results.

Subclinical left ventricular dysfunction assessed by two-dimensional speckle tracking echocardiography in asymptomatic patients with carotid stenosis

Abstract

The relationship between subclinical left ventricular (LV) dysfunction and atherosclerosis may have been underestimated in the past, which might be responsible for the high incidence of premature death in individuals with carotid stenosis. We sought to evaluate the underlying myocardial dysfunction in asymptomatic carotid stenosis patients using speckle tracking echocardiography (STE). Fifty patients with carotid stenosis ≥ 50% and a preserved LV ejection fraction (LVEF), and 45 controls without carotid stenosis who were matched in terms of vascular comorbidities were enrolled. All participants underwent carotid ultrasound and echocardiographic examination. The global LV longitudinal strain (GLS) was measured using STE. Compared with the control group, the e’ of the mitral annular velocity and GLS were decreased in asymptomatic carotid stenosis patients (p < 0.05), however, the LVEF was well preserved. Based on a predefined cutoff for subclinical LV systolic dysfunction that was defined at a GLS <  − 18%, this dysfunction was detected in 22 patients with carotid stenosis (44%) and in 10 patients in the control group (22%) (p < 0.05). The GLS was negatively correlated with the levels of low-density lipoprotein cholesterol (r =  − 0.356, p < 0.05) and triglyceride (r =  − 0.396, p < 0.05). In conclusion, LV diastolic and systolic functioning were significantly decreased in patients with asymptomatic carotid stenosis, and dyslipidemia likely contributed to the subclinical LV dysfunction in these patients. Our findings indicated the importance of detecting LV subclinical dysfunction and early intervention in this patient population.

Conservative gadolinium administration to patients with Duchenne muscular dystrophy: decreasing exposure, cost, and time, without change in medical management

Abstract

Cardiac MR (CMR) is increasingly used to assess for cardiac involvement in patients with Duchenne muscular dystrophy (DMD). The frequent use of gadolinium based contrast agents (GBCAs) has been called into question with reports of intracranial gadolinium deposition in patients receiving multiple administrations. We adopted a conservative GBCA administration policy, limiting the frequency of GBCA exposure in patients with previously documented late gadolinium enhancement. The aim of our study was to evaluate the clinical effects of this policy change. Data were retrospectively reviewed on 405 consecutive patients with DMD who underwent CMR evaluation. Patients were grouped into conservative GBCA administration or historical control. CMR reports were evaluated and clinical reports were reviewed to determine actionable changes. Ohio Medicaid reimbursements were used to estimate costs. A total of 187 patients comprised the conservative GBCA group and 218 patients the historical cohort. The conservative GBCA group had lower contrast administration rates (84% vs. 99%, p < 0.0001), shorter scan times (35.2 vs. 39.0 min, p < 0.0001), and lower estimated medical costs ($339 vs. $351/study). There was no change regarding the initial presence of first-time late gadolinium enhancement, and no difference in actionable change. Contrast administration substantially decreased 7 months post-policy change (65%) compared to the initial 7 months (96%, p < 0.0001). In the current era with unclear concern for intracranial gadolinium deposition, thoughtful GBCA administration is warranted in patients anticipated to undergo multiple CMRs. Our updated approach has resulted in fewer patients receiving contrast, shorter scan times, and less medical costs, without appreciable changes to patient management.

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