Association between coronary plaque volume and myocardial ischemia detected by dynamic perfusion CT imaging.

Introduction: We aimed to evaluate the relationship between quantitative plaque metrics derived from coronary CT angiography (CTA) and segmental myocardial ischemia using dynamic perfusion CT (DPCT). Methods: In a prospective single-center study, patients with > 30% stenosis on rest CTA underwent regadenoson stress DPCT. 480 myocardium segments of 30 patients were analyzed. Quantitative plaque assessment included total plaque volume (PV), area stenosis, and remodeling index (RI). High-risk plaque (HRP) was defined as low-attenuation plaque burden > 4% or RI > 1.1. Absolute myocardial blood flow (MBF) and relative MBF (MBFi: MBF/75th percentile of all MBF values) were quantified. Linear and logistic mixed models correcting for intra-patient clustering and clinical factors were used to evaluate the association between total PV, area stenosis, HRP and MBF or myocardial ischemia (MBF < 101 ml/100 g/min). Results: Median MBF and MBFi were 111 ml/100 g/min and 0.94, respectively. The number of ischemic segments were 164/480 (34.2%). Total PV of all feeding vessels of a given myocardial territory differed significantly between ischemic and non-ischemic myocardial segments (p = 0.001). Area stenosis and HRP features were not linked to MBF or MBFi (all p > 0.05). Increase in PV led to reduced MBF and MBFi after adjusting for risk factors including hypertension, diabetes, and statin use (per 10 mm3; ß = -0.035, p < 0.01 for MBF; ß = -0.0002, p < 0.01 for MBFi). Similarly, using multivariate logistic regression total PV was associated with ischemia (OR = 1.01, p = 0.033; per 10 mm3) after adjustments for clinical risk factors, area stenosis and HRP. Conclusion: Total PV was independently associated with myocardial ischemia based on MBF, while area stenosis and HRP were not.

Subclinical leaflet thrombosis after transcatheter aortic valve implantation is associated with silent brain injury on brain magnetic resonance imaging.

AIMS: Whether hypoattenuated leaflet thickening (HALT) following transcatheter aortic valve implantation (TAVI) carries a risk of subclinical brain injury (SBI) is unknown. We investigated whether HALT is associated with SBI detected on magnetic resonance imaging (MRI), and whether post-TAVI SBI impacts the patients' cognition and outcome. METHODS AND RESULTS: We prospectively enrolled 153 patients (age: 78.1 ± 6.3 years; female 44%) who underwent TAVI. Brain MRI was performed shortly post-TAVI and 6 months later to assess the occurrence of acute silent cerebral ischaemic lesions (SCIL) and chronic white matter hyperintensities (WMH). HALT was screened by cardiac computed tomography (CT) angiography (CTA) 6 months post-TAVI. Neurocognitive evaluation was performed before, shortly after and 6 months following TAVI. At 6 months, 115 patients had diagnostic CTA and 10 had HALT. HALT status, baseline, and follow-up MRIs were available in 91 cases. At 6 months, new SCIL was evident in 16%, new WMH in 66%. New WMH was more frequent (100 vs. 62%; P = 0.047) with higher median volume (319 vs. 50 mm3; P = 0.039) among HALT-patients. In uni- and multivariate analysis, HALT was associated with new WMH volume (beta: 0.72; 95%CI: 0.2-1.39; P = 0.009). The patients' cognitive trajectory from pre-TAVI to 6 months showed significant association with the 6-month SCIL volume (beta: -4.69; 95%CI: -9.13 to 0.27; P = 0.038), but was not related to the presence or volume of new WMH. During a 3.1-year follow-up, neither HALT [hazard ratio (HR): 0.86; 95%CI: 0.202-3.687; P = 0.84], nor the related WMH burden (HR: 1.09; 95%CI: 0.701-1.680; P = 0.71) was related with increased mortality. CONCLUSIONS: At 6 months post-TAVI, HALT was linked with greater WMH burden, but did not carry an increased risk of cognitive decline or mortality over a 3.1-year follow-up (NCT02826200).

Blood-filled cyst of the tricuspid valve: Multiple cardiac disorders, one surgical case.

BACKGROUND: Intracardiac blood cysts are an exceedingly rare occurrence in adulthood. Detailed imaging modalities aid in the diagnosis of such incidental lesions and procedure planning. METHODS: We report the case of a 51-year-old male accusing dyspnea on exertion as a sole symptom which led to the discovery of multiple cardiac anomalies, namely, severe aortic valve insufficiency on a bicuspid aortic valve, ascending aortic aneurysm, a cystic mass on the tricuspid valve, patent foramen ovale, and an occluded right coronary artery. RESULTS: The disorders were managed in a single surgical intervention, the resected mass being confirmed as a blood cyst. CONCLUSIONS: Our case presents a unique association of cardiac disorders, including a highly uncommon intracardiac blood-filled cyst, and underlines the importance of multimodality imaging and interdisciplinary approach in the successful management of such complex cases.

Fully automatic segmentation of right and left ventricle on short-axis cardiac MRI images.

Cardiac magnetic resonance imaging (CMR) is a widely used non-invasive imaging modality for evaluating cardiovascular diseases. CMR is the gold standard method for left and right ventricular functional assessment due to its ability to characterize myocardial structure and function and low intra- and inter-observer variability. However the post-processing segmentation during the functional evaluation is time-consuming and challenging. A fully automated segmentation method can assist the experts; therefore, they can do more efficient work. In this paper, a regression-based fully automated method is presented for the right- and left ventricle segmentation. For training and evaluation, our dataset contained MRI short-axis scans of 5570 patients, who underwent CMR examinations at Heart and Vascular Center, Semmelweis University Budapest. Our approach is novel and after training the state-of-the-art algorithm on our dataset, our algorithm proved to be superior on both of the ventricles. The evaluation metrics were the Dice index, Hausdorff distance and volume related parameters. We have achieved average Dice index for the left endocardium: 0.927, left epicardium: 0.940 and right endocardium: 0.873 on our dataset. We have also compared the performance of the algorithm to the human-level segmentation on both ventricles and it is similar to experienced readers for the left, and comparable for the right ventricle. We also evaluated the proposed algorithm on the ACDC dataset, which is publicly available, with and without transfer learning. The results on ACDC were also satisfying and similar to human observers. Our method is lightweight, fast to train and does not require more than 2 GB GPU memory for execution and training.

Quantification of hypo-attenuated leaflet thickening after transcatheter aortic valve implantation: clinical relevance of hypo-attenuated leaflet thickening volume.

AIMS: Our aim was to establish an objective, quantitative methodology for volumetric hypo-attenuated leaflet thickening (HALT) diagnosis and evaluate its clinical significance. METHODS AND RESULTS: We prospectively enrolled 144 patients who underwent transcatheter aortic valve implantation (TAVI) between 2011 and 2016. At inclusion, cardiac computed tomography angiography (CTA), transthoracic echocardiography, and brain magnetic resonance imaging (MRI) were performed. We quantified HALT on CTA datasets by segmenting the inner volume of TAVI frame at the level of leaflets and extracted voxels between a threshold of -200 to 200 HU based on prior recommendation. The median HALT volume was 72 [inter-quartile range (IQR): 1-154] mm3 (intra- and inter-reader agreement: intra-class correlation coefficient = 0.92 and 0.94, respectively) and 79% (n = 87/111) of the patients had HALT >0 mm3. In multivariate linear regression, oral anti-coagulation (ß: -0.32; 95% CI: -0.62 to -0.01; P = 0.004) and history of myocardial infarction (ß: 0.32; 95% CI: 0.01-0.63; P = 0.043) were associated with HALT quantity. Log-transformed HALT volume was associated with elevated (>13 mmHg) aortic mean gradient (AMG, OR: 12.85; 95% CI: 1.96-152.93; P = 0.021) and moderate-to-severe valvular degeneration (AMG ≥ 20 mmHg or ΔAMG ≥ 10 mmHg; OR: 10.56; 95% CI: 1.44-148.71; P = 0.046) but did not predict ischaemic brain lesions on MRI or all-cause death after a median follow-up of 29 (IQR: 11-29) months (all P > 0.05). CONCLUSION: Through systematic analysis of asymptomatic patients with TAVI, an objective and reproducible methodology was feasible for volumetric measurement of HALT. Anti-coagulation might have a protective effect against HALT. Ischaemic brain lesions and all-cause death were not associated with HALT; nevertheless, it might deteriorate prosthesis function due to its association with elevated AMG. CLINICAL TRIAL REGISTRATION: http//:www.ClinicalTrials.gov; NCT02826200.

How are ECG parameters related to cardiac magnetic resonance images? Electrocardiographic predictors of left ventricular hypertrophy and myocardial fibrosis in hypertrophic cardiomyopathy.

BACKGROUND: Structural myocardial changes in hypertrophic cardiomyopathy (HCM) are associated with different abnormalities on electrocardiographs (ECGs). The diagnostic value of the ECG voltage criteria used to screen for left ventricular hypertrophy (LVH) may depend on the presence and degree of myocardial fibrosis. Fibrosis can cause other changes in ECG parameters, such as pathological Q waves, fragmented QRS (fQRS), or repolarization abnormalities. METHODS: We investigated 146 patients with HCM and 35 healthy individuals who underwent cardiac magnetic resonance imaging (CMR; with late gadolinium enhancement [LGE] in HCM patients) and standard 12-lead ECGs. On the ECG, depolarization and repolarization abnormalities, the Sokolow-Lyon index, the Cornell index, and the Romhilt-Estes score were evaluated. The left ventricular ejection fraction, volumes, and myocardial mass (LVM) were quantified. Myocardial fibrosis was quantified on LGE images. RESULTS: The sensitivity of the Romhilt-Estes score was the highest (75%), and this hypertrophy criterion had the strongest correlation with the LVM index (p < .0001; r = .41). The amount of fibrosis was negatively correlated with the Cornell index (p = .015; r = -.201) and the Sokolow-Lyon index (p = .005; r = -.23), and the Romhilt-Estes score was independent of fibrosis (p = .757; r = 0.026). fQRS and strain pattern predicted more fibrosis, while the Cornell index was a negative predictor of myocardial fibrosis (p < .0001). Among others, the strain pattern was an independent predictor of the LVM (p < .0001). CONCLUSION: The Romhilt-Estes score is the most sensitive ECG criterion for detecting LVH in HCM patients, as myocardial fibrosis does not affect this criterion. The presence of fQRS and strain pattern predicts myocardial fibrosis.

Subclinical leaflet thrombosis is associated with impaired reverse remodelling after transcatheter aortic valve implantation.

AIMS: Cardiac CT is increasingly applied for planning and follow-up of transcatheter aortic valve implantation (TAVI). However, there are no data available on reverse remodelling after TAVI assessed by CT. Therefore, we aimed to evaluate the predictors and the prognostic value of left ventricular (LV) reverse remodelling following TAVI using CT angiography. METHODS AND RESULTS: We investigated 117 patients with severe, symptomatic aortic stenosis (AS) who underwent CT scanning before and after TAVI procedure with a mean follow-up time of 2.6 years after TAVI. We found a significant reduction in LV mass (LVM) and LVM indexed to body surface area comparing pre- vs. post-TAVI images: 180.5 ± 53.0 vs. 137.1 ± 44.8 g and 99.7 ± 25.4 vs. 75.4 ± 19.9 g/m2, respectively, both P < 0.001. Subclinical leaflet thrombosis (SLT) was detected in 25.6% (30/117) patients. More than 20% reduction in LVM was defined as reverse remodelling and was detected in 62.4% (73/117) of the patients. SLT, change in mean pressure gradient on echocardiography and prior myocardial infarction was independently associated with LV reverse remodelling after adjusting for age, gender, and traditional risk factors (hypertension, body mass index, diabetes mellitus, and hyperlipidaemia): OR = 0.27, P = 0.022 for SLT and OR = 0.22, P = 0.006 for prior myocardial infarction, OR = 1.51, P = 0.004 for 10 mmHg change in mean pressure gradient. Reverse remodelling was independently associated with favourable outcomes (HR = 0.23; P = 0.019). CONCLUSION: TAVI resulted in a significant LVM regression on CT. The presence of SLT showed an inverse association with LV reverse remodelling and thus it may hinder the beneficial LV structural changes. Reverse remodelling was associated with improved long-term prognosis.

Left ventricular and atrial strain imaging with cardiac computed tomography: Validation against echocardiography.

BACKGROUND: Data on left ventricular (LV) deformation imaging using CT angiography (CTA) are scarce and the feasibility of atrial deformation analysis by CT has not been addressed. We aimed to compare 2D echocardiographic and CT derived LV and left atrial (LA) global longitudinal strain (GLS) obtained by using a novel feature tracking algorithm in patients following transcatheter aortic valve implantation. METHODS: Twenty-eight patients were included who underwent retrospectively-gated 256-slice CTA and speckle-tracking echocardiography (STE) on the same day. CT datasets in 10% increments were reconstructed throughout the cardiac cycle. LV GLS and LA global peak reservoir strain (LA GS) was measured. RESULTS: Median absolute values for LV GLS were 19.9 [14.8-22.4] vs. 19.9 [16.8-24.7], as measured by CT vs STE, respectively (p = 0.017). We found good inter-modality correlation for LV GLS (ρ = 0.78, p < 0.05) with a mean bias of -1.6. Regarding atrial measurements, the median LA GS was 19.0 [13.5-27.3] for CT vs. 28.0 [17.5-32.6] for STE (p < 0.001) with a mean bias of -5.6 between CT and STE and a correlation coefficient of ρ = 0.87, p < 0.001. CT measurements were highly reproducible: intra-observer intra-class correlation coefficient was 0.96 for LV GLS and 0.95 for LA GS. CONCLUSION: We detected good correlation between CTA and echocardiography-based LV and LA longitudinal strain parameters. CTA provides accurate strain measurements with high reproducibility. Feature tracking-based deformation analysis could provide a clinically important addition to CT examinations by complementing anatomical information with functional data.

Esmolol is noninferior to metoprolol in achieving a target heart rate of 65 beats/min in patients referred to coronary CT angiography: a randomized controlled clinical trial.

BACKGROUND: Coronary CT angiography (CTA) is an established tool to rule out coronary artery disease. Performance of coronary CTA is highly dependent on patients' heart rates (HRs). Despite widespread use of ß-blockers for coronary CTA, few studies have compared various agents used to achieve adequate HR control. OBJECTIVE: We sought to assess if the ultrashort-acting ß-blocker intravenous esmolol is at least as efficacious as the standard of care intravenous metoprolol for HR control during coronary CTA. METHODS: Patients referred to coronary CTA with a HR >65 beats/min despite oral metoprolol premedication were enrolled in the study. We studied 412 patients (211 male; mean age, 57 ± 12 years). Two hundred four patients received intravenous esmolol, and 208 received intravenous metoprolol with a stepwise bolus administration protocol. HR and blood pressure were recorded at arrival, before, during, immediately after, and 30 minutes after the coronary CTA scan. RESULTS: Mean HRs of the esmolol and metoprolol groups were similar at arrival (78 ± 13 beats/min vs 77 ± 12 beats/min; P = .65) and before scan (68 ± 7 beats/min vs 69 ± 7 beats/min; P = .60). However, HR during scan was lower in the esmolol group vs the metoprolol group (58 ± 6 beats/min vs 61 ± 7 beats/min; P < .0001), whereas HRs immediately and 30 minutes after the scan were higher in the esmolol group vs the metoprolol group (68 ± 7 beats/min vs 66 ± 7 beats/min; P = .01 and 65 ± 8 beats/min vs 63 ± 8 beats/min; P < .0001; respectively). HR ≤ 65 beats/min was reached in 182 of 204 patients (89%) who received intravenous esmolol vs 162 of 208 of the patients (78%) who received intravenous metoprolol (P < .05). Of note, hypotension (systolic BP <100 mm Hg) was observed right after the scan in 19 patients (9.3%) in the esmolol group and in 8 patients (3.8%) in the metoprolol group (P < .05), whereas only 5 patients (2.5%) had hypotension 30 minutes after the scan in the esmolol group compared to 8 patients (3.8%) in the metoprolol group (P = .418). CONCLUSION: Intravenous esmolol with a stepwise bolus administration protocol is at least as efficacious as the standard of care intravenous metoprolol for HR control in patients who undergo coronary CTA.