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We sought to evaluate whether differences in left ventricular assist device (LVAD) canula alignment are associated with stroke. There is a paucity of clinical data on contribution of LVAD canulae alignment to strokes. We conducted a retrospective analysis of patients who underwent LVAD implantation at Houston Methodist hospital from 2011 to 2016 and included those who had undergone cardiac computed tomography (CT) with contrast. LVAD graft alignment using X-ray, echocardiography, and cardiac CT was evaluated. The primary outcome was stroke within 1 year of LVAD implantation. Of the 101 patients that underwent LVAD Implantation and cardiac CT scan during the study period, 78 met inclusion criteria. The primary outcome occurred in 12 (15.4%) patients with a median time to stroke of 77 days (interquartile range: 42–132 days). Of these, 10 patients had an ischemic and two had hemorrhagic strokes. The predominant device type was Heart Mate II (94.8%). Patients with LVAD outflow cannula to aortic angle lesser than 37.5° and those with outflow graft diameter of anastomosis less than 1.5 cm (assessed by cardiac CT) had significantly higher stroke risk ( p

The primary objective was to compare the accuracy of dynamic computed tomography (CT) angiography (d-CTA) with standardized triphasic contrast enhanced CT angiography (t-CTA) in diagnosing endoleak type after endovascular aortic repair (EVAR) using digital subtraction angiography (DSA) as reference standard. The secondary objective was to study the impact of d-CTA on image fusion-guided endoleak embolization.A retrospective review of patients who underwent d-CTA imaging after EVAR between March 2019 and July 2021 was performed. Deidentified images were independently reviewed by two-two blinded readers to document endoleak type and target vessels. An impact of d-CTA-guided embolization was evaluated by a number of planning angiograms, radiation exposure, and accuracy of target vessel overlay.During the study period, 52 patients underwent d-CTA and 19 had all 3 modalities available for analysis. DSA imaging confirmed 4 (21.0%) type-I, 14 (73.7%) type-II, and 1 (5.3%) type-III endoleak. Findings from d-CTA matched with DSA in 19/19 cases (100%), whereas t-CTA matched in 14/19 cases (73.7%). In type-II endoleaks, the number of target vessels identified by d-CTA, t-CTA, and DSA were 23, 17, and 16, respectively. Mean dose-length product from d-CTA and t-CTA was 1,445 ± 551 and 1,612 ± 530 mGy × cm (P = 0.26). Nine patients underwent d-CTA-guided type-II endoleak embolization, using a median of 1 (range: 1-4) planning angiogram before embolization using 21.6 (± 8.7)% of total procedural radiation dose. Target vessel overlay was accurate in 9/9 (100%) cases.Dynamic, time-resolved CTA is more accurate compared to standardized triphasic contrast enhanced CTA in diagnosing endoleak type after EVAR. In type-II endoleak, d-CTA better identified target vessels and enabled safe, targeted embolization.

Better time-resolved imaging of stent grafts in the ascending aorta and arch accounting for cardiac motion is necessary to understand device-related complications and endoleaks. This report describes dynamic time-resolved computed tomographic angiography (d-CTA) and its combination with electrocardiography gating (d-gated CTA) to image stent grafts in the ascending aorta and to characterize endoleaks more clearly.d-CTA involves multiple scans acquired at different time points along the contrast enhancement curve. d-Gated CTA involves concomitant electrocardiography gating in a predefined cardiac phase minimizing motion-induced artifacts.This report illustrates the utility of d-CTA and d-gated CTA in 2 clinical cases. d-CTA demonstrated a type 1A endoleak in a patient with an aortic arch aneurysm treated with total arch debranching and a thoracic stent graft. d-gated CTA demonstrated a type 1A endoleak in a patient with an ascending aortic pseudoaneurysm treated with aortic cuff placement.Dynamic, cardiac-gated CTA enables time-resolved angiographic imaging of the ascending aorta and arch without any cardiac motion-related artifacts. Such advanced imaging techniques help with better characterization of endoleaks after stent graft deployment in the ascending aorta and arch.

The aim of this study was to compare the incremental prognostic value of coronary computed tomography (CT) angiography (CCTA)-derived machine learning fractional flow reserve CT (ML-FFRct) versus that of ischemia detected on single-photon emission-computed tomography (SPECT) myocardial perfusion imaging (MPI) on incident cardiovascular outcomes.SPECT MPI and ML-FFRct are noninvasive tools that can assess the hemodynamic significance of coronary atherosclerotic disease.We studied a retrospective cohort of consecutive patients who underwent clinically indicated CCTA and SPECT MPI. ML-FFRct was computed using a ML prototype. The primary outcome was all-cause mortality and nonfatal myocardial infarction (D/MI), and the secondary outcome was D/MI and unplanned revascularization, percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) occurring more than 90 days postimaging. Multiple nested multivariate cox regression was used to model a scenario wherein an initial anatomical assessment was followed by a functional assessment.A total of 471 patients (mean age: 64 ± 13 year; 53% males) were included. Comorbidities were prevalent (78% hypertension, 66% diabetes, 81% dyslipidemia). ML-FFRct was 0.8 in at least 1 proximal/midsegment was present in 41.6% of patients, and ischemia on MPI was present in 13.8%. After a median follow-up of 18 months, 7% of patients (n = 33) experienced D/MI. On multivariate Cox proportional analysis, the presence of ischemia on MPI but not ML-FFRct significantly predicted D/MI (HR: 2.3; 95% CI: 1.0-5.0; P = 0.047; or HR: 0.7; 95% CI: 0.3-1.4; P = 0.306 respectively) when added to CCTA obstructive stenosis. Furthermore, the model with SPECT ischemia had higher global chi-square result and significantly improved reclassification. Results were similar using the secondary outcome and on several sensitivity analyses.In a high-risk patient cohort, SPECT MPI but not ML-FFRct adds independent and incremental prognostic information to CCTA-based anatomical assessment and clinical risk factors in predicting incident outcomes.

Purpose: Our purpose was to study the accuracy of dynamic computed tomography angiography (d-CTA) in characterizing endoleak type, inflow vessels as compared with digital subtraction angiography (DSA) using qualitative and quantitative analysis. Methods: Between March 2019 and January 2021, all patients who underwent d-CTA imaging after EVAR were retrospectively reviewed. Two blinded independent reviewers qualitatively reviewed d-CTA and DSA images. Quantitative region of interest (ROI) analysis was performed by measuring time-resolved contrast enhancement within the aorta and endoleak lesion(s) in the aneurysm sac. Differences between time-to-peak enhancement (Δ TTP) across different ROIs were quantified. Results: A total of 48 patients underwent d-CTA during the study period, of whom 24 patients had abdominal EVAR and DSA imaging for comparison. Qualitative review of DSA imaging showed type I (n=4), type II (n=16), and type III (n=2) and no endoleak (n=2). In 23 of 24 patients (95.8%), d-CTA findings correlated with DSA findings for endoleak type. One patient had a type III endoleak that was demonstrated only in d-CTA (arising from defect in polymer sealing ring of Ovation stent graft) imaging. In type II endoleak cases, d-CTA identified more inflow vessels than DSA imaging (33 vs 21 vessels, p=0.010). Quantitative analysis showed mean (±SD) Δ TTP values for type I endoleak as 1.8 (±1.8) seconds, type II as 9.6 (±3.5) seconds, and for type III endoleak as 5.6 (±1.3) seconds. Conclusion: Dynamic CTA can accurately characterize aortic endoleak type, inflow vessels as compared with DSA imaging. Quantitative parameters such as Δ TTP enhancement can help better differentiate endoleak types and provide an objective approach to endoleak diagnosis.

Background New data suggests long term outcomes of coronary revascularization based on instantaneous wave free ratio (iFR) are equivalent to invasive fractional flow reserve (FFR). We aimed to evaluate the correlation between non-invasive FFR derived from cardiac CT (FFR CT) and iFR. Methods Data from 21 patients with 26 vessels, who underwent both FFRCT computation and invasive iFR measurement, were analysed. We evaluated diagnostic performance of FFRCT according to two cut-off values of ≤0.80 and ≤0.70 with iFR ≤0.89 as the reference standard. Results In a per vessel analysis, the average diameter stenosis was 59%, mean FFRCT was 0.81 while mean iFR was 0.90. Using an FFRCT cut-off of 0.80, the sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy for FFRCT were 86%, 84%, 67%, 94%, and 85% respectively. When the cut-off was lowered to 0.70, the sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy for FFRCT were 57%, 100%, 100%, 86% and 88% respectively. Conclusion FFRCT correlates well with iFR in this small retrospective study. Larger studies are required to confirm this finding.

Purpose: To illustrate dynamic, time-resolved CTA (d-CTA) imaging technique in characterizing aortic endoleak type/inflow using quantitative parameters and its value in providing image guidance for targeted treatment approach. Technique: Dedicated endoleak protocol involved acquiring multiple time-resolved contrast enhanced scans using third-generation CT scanner (Somatom Force®, Siemens Healthineers). Parameters such as scan field of view (FOV), kV, number/timing of scans were customized based on patient’s body-mass-index, timing bolus, and prior imaging findings. D-CTA image datasets were evaluated qualitatively and quantitatively using time-attenuation curves (TAC) analysis after motion correction using a dedicated software ( syngo.via®, Siemens). D-CTA findings from 4 illustrative cases demonstrating type I, type II (inferior mesenteric and lumbar artery inflow), and type III endoleak were illustrated. TAC analysis with time to peak parameter enabled better characterization of endoleak type and inflow. During endoleak intervention, target vessels from d-CTA images were electronically annotated and overlaid on fluoroscopy using 2D−3D image fusion to provide image guidance for targeted treatment. Conclusion: D-CTA imaging with TAC analysis characterizes aortic endoleak type and inflow, in addition to providing image guidance for targeted endoleak treatment. Such dynamic, time-resolved imaging techniques may provide further insights into understanding aortic endoleak that remains an Achilles heel for endovascular aortic aneurysm repair.

The International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial showed no difference in outcomes between medical therapy vs coronary revascularization in the management of patients with stable coronary artery disease. We aimed to determine the percentage of patients with at least moderate ischemia that would have been eligible for enrollment and evaluate the outcomes of those who would not. Consecutive patients who underwent cardiac single-photon emission computed tomography (SPECT) between April 2016 and September 2019 were identified and all-cause mortality was determined. There were a total of 1508 patients (mean age 67 ± 11.6 years, 69.5% males) with any perfusion defect on SPECT. Patients had a high prevalence of cardiac risk factors (73.4% with hypertension and 54.4% with diabetes mellitus.) Nearly half (709, 47%) had moderate-to-severe ischemia but over two-thirds (479/709, 66.3%) had at least one ISCHEMIA trial exclusion criteria. Patients meeting ISCHEMIA enrollment criteria had a significantly lower all-cause mortality than those who would have been excluded (3.91% vs. 11.3%, respectively, P

Prosthetic valve thrombosis is the second leading cause of prosthetic valve deterioration and is being more readily diagnosed with the use of echocardiography and multidetector cardiac CT. Presentation of valve thrombosis can be acute or subacute and any change in clinical status of a patient with a prosthetic valve should raise a suspicion of prosthetic valve thrombosis. Diagnosis entails detailed clinical examination and comprehensive imaging. The choice of therapeutic options includes anticoagulation, fibrinolytic therapy, or valve replacement. Antiplatelet and anticoagulation therapy remain the mainstay of thrombosis prevention in patients with a prosthetic valve and a personalized approach is required to optimize prosthetic valve function and minimize the risk of bleeding.

The paper discusses a stabilization of a finite element method for the equations of fluid motion in a time-dependent domain. After experimental convergence analysis, the method is applied to simulate a blood flow in the right ventricle of a post-surgery patient with the transposition of the great arteries disorder. The flow domain is reconstructed from a sequence of 4D CT images. The corresponding segmentation and triangulation algorithms are also addressed in brief.

Coronary computed tomography angiography (CCTA) derived machine learning fractional flow reserve (ML-FFRCT) can assess the hemodynamic significance of coronary artery stenoses. We aimed to assess sex differences in the association of ML-FFRCT and incident cardiovascular outcomes. We studied a retrospective cohort of consecutive patients who underwent clinically indicated CCTA and single photon emission computed tomography (SPECT). Obstructive stenosis was defined as ≥ 70% stenosis severity in non-left main vessels or ≥ 50% in the left main coronary. ML-FFRCT was computed using a machine learning algorithm with significant stenosis defined as ML-FFRCT CT CT (0.76 (0.53–0.86) vs. 0.71 (0.47–0.84); p = 0.047). In multivariable adjusted models, there was no significant association between ML-FFRCT CT was higher in women than men. There was no significant association between ML-FFRCT and incident mortality or MI and no evidence that the prognostic value of ML-FFRCT differs by sex.

A 54-year-old woman with a mechanical mitral valve replacement presented with recurrent admissions for pneumonia and pulmonary edema. Multimodality imaging revealed mobile masses on the prosthesis and discrepant point of care and inpatient international normalized ratio levels owing to antiphospholipid antibody cross-reactivity on the outpatient assay. The prosthetic valve thromboses resolved with therapeutic anticoagulation. (Level of Difficulty: Beginner.), Graphical abstract, A 54-year-old woman with a mechanical MVR presented with recurrent admissions for pneumonia and pulmonary edema. Multimodality imaging revealed…

In the United States, more than 80% of all abdominal aortic aneurysms are treated by endovascular aortic aneurysm repair (EVAR). The endovascular approach warrants good early results, but adequate follow-up imaging after EVAR is imperative to maintain long-term positive outcomes. Potential graft-related complications are graft migration, infection, fraction, and endoleaks, with the last one being the most common. The most frequently used imaging after EVAR is computed tomography angiography (CTA) and duplex ultrasound. Dynamic, time-resolved computed tomography angiography (d-CTA) is a reasonably new technique to characterize the endoleaks. Multiple scans are done sequentially around the endograft during acquisition that grants good visualization of the contrast passage and graft-related complications. This high diagnostic accuracy of d-CTA can be implemented into therapy via image fusion and reduce additional radiation and contrast material exposure. This protocol describes the technical aspects of this modality: patient selection, preliminary image review, d-CTA scan acquisition, image processing, qualitative and quantitative endoleak characterization. The steps of integrating dynamic CTA into intra-operative fluoroscopy using 2D-3D fusion-imaging to facilitate targeted embolization are also demonstrated. In conclusion, time-resolved, dynamic CTA is an ideal modality for endoleak characterization with additional quantitative analysis. It can reduce radiation and iodinated contrast material exposure during endoleak treatment by guiding interventions.

Introduction Cardiac computed tomography angiography (CCTA) derived fractional flow reserve (FFRCT) has been shown to add incremental diagnostic value by providing functional severity of coronary lesion in patients with coronary artery disease (CAD). Purpose We aimed to assess the prognostic value of FFRCT in patients with suspected CAD. Methods Consecutive patients who had clinically indicated CCTA and FFRCT determination at a tertiary care cardiology practice were included. FFRCT was determined off-site using computational flow dynamics. Patients were followed for major adverse cardiovascular events (MACE, inclusive of all-cause death, non-fatal myocardial infarction, and late percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) 90-days after imaging test.) Results A total of 667 patients with at least Coronary Artery Disease Reporting & Data System (CAD-RADS) 2 were included. Mean age was 68±10 years, 37% were women, 73% had hypertension, 12% had diabetes and 61% had dyslipidemia. More than half (57%) of the patients had moderate (CAD-RADS 3) stenosis. FFRCT Conclusion Our results suggest that in a real-world cohort of patients with suspected CAD, FFRCT can identify patients at higher risk of incident cardiovascular outcomes. Funding Acknowledgement Type of funding sources: None.

The International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial showed no difference in outcomes between medical therapy vs coronary revascularization in the management of patients with stable coronary artery disease. We aimed to determine the percentage of patients with at least moderate ischemia that would have been eligible for enrollment and evaluate the outcomes of those who would not.Consecutive patients who underwent cardiac single-photon emission computed tomography (SPECT) between April 2016 and September 2019 were identified and all-cause mortality was determined.There were a total of 1508 patients (mean age 67 ± 11.6 years, 69.5% males) with any perfusion defect on SPECT. Patients had a high prevalence of cardiac risk factors (73.4% with hypertension and 54.4% with diabetes mellitus.) Nearly half (709, 47%) had moderate-to-severe ischemia but over two-thirds (479/709, 66.3%) had at least one ISCHEMIA trial exclusion criteria. Patients meeting ISCHEMIA enrollment criteria had a significantly lower all-cause mortality than those who would have been excluded (3.91% vs. 11.3%, respectively, P .001).Our results show that ISCHEMIA selected a relatively small subset of lower risk patients among the larger higher risk group of patients with moderate-to-severe ischemia typical to most cardiology centers.

New data suggests long term outcomes of coronary revascularization based on instantaneous wave free ratio (iFR) are equivalent to invasive fractional flow reserve (FFR). We aimed to evaluate the correlation between non-invasive FFR derived from cardiac CT (FFRData from 21 patients with 26 vessels, who underwent both FFRIn a per vessel analysis, the average diameter stenosis was 59%, mean FFRFFR

Coronary computed tomographic angiography (CCTA) with prospective electrocardiographic gating reduces radiation exposure, but its prognostic power for predicting cardiovascular risk in patients with suspected CAD has not been fully validated. To determine whether prospective gating performs as well as retrospective gating in this population, we compared these scan modes in patients undergoing 64-slice CCTA. From January 2009 through September 2011, 1,407 patients underwent CCTA; of these, 915 (mean age, 57.8 ± 13.5 yr; 54% male) had suspected coronary artery disease at the time of CCTA and were included in the study. Prospective gating was used in 195 (21%) and retrospective gating in 720 (79%). The mean follow-up duration was 2.4 ± 0.9 years. Overall, 390 patients (42.6%) had normal results on CCTA, 382 (41.7%) had nonobstructive coronary artery disease, and 143 (15.6%) had obstructive disease. Major adverse cardiac events occurred in 32 patients (3.5%): 11 cardiac deaths, 15 late revascularizations, and 6 nonfatal myocardial infarctions. Total event occurrences were similar in both groups (retrospective, 3.8%; prospective, 2.6%; P=0.42), as were the occurrences of each type of event. On adjusted multivariate analysis, nonobstructive (P=0.015) and obstructive (P The prognostic value of CCTA with prospective electrocardiographic gating compares favorably with that of retrospective gating, and it involves significantly less radiation exposure.

In situ detection of Cu2+ ions in the effluent from thin-film transistor-liquid crystal display (TFT-LCD) manufacturing facility has been successfully achieved using thiol-capped CdS/ZnS quantum do...

Purpose: Cardiac computed tomographic angiography (CCTA) - derived measures of coronary artery disease (CAD) burden such as segment involvement score (SIS), which quantifies the number of segments with plaque, have been shown to independently predict incident cardiovascular events. We aimed to compare the added prognostic value of plaque burden to CCTA anatomic assessment and single photon emission computed tomography (SPECT) physiologic assessment in a high-risk cohort undergoing both tests.Methods: Consecutive patients who underwent clinically indicated CCTA and SPECT myocardial imaging for suspected CAD at a tertiary care cardiology practice were included. Stenosis severity and SIS were determined from CCTA, and presence of ischemia was determined from SPECT. Patients were followed for major adverse cardiovascular events (MACE, inclusive of all-cause death, non-fatal myocardial infarction, and percutaneous coronary intervention or coronary artery bypass grafting 90-days after imaging test.)Results: A total of 956 patients were included. Mean age was 61.1 ± 14.2 years, 54% were men, 89% had hypertension, 81% had diabetes, 84% had dyslipidemia and 56% had recorded chest pain. Obstructive stenosis (left main ≥ 50%, all other coronary segments ≥ 70%) and ischemia were observed in similar number of patients (14%). After a median follow-up of 31 months, 102 patients (11%, 29.2 events per 1000 person-year) experienced a MACE. In multivariable Cox regression models, SIS significantly predicted outcomes and improved risk discrimination in models with CCTA obstructive stenosis (HR 1.15 95% CI 1.09 - 1.21 p= Conclusion: Our results suggest that in high-risk patients with suspected CAD, plaque burden adds incremental prognostic value over established measures in predicting incident cardiovascular outcomes.

Reduced graphene oxide (rGO) has been prepared through hydrothermal reduction, an environmentally safe reduction of graphene oxide (GO). rGO is used to fabricate a highly compatible and orderly stacked lamellar structure of composite membranes with chitosan (CS). This method also facilitates a continuous large-scale fabrication of membranes. Conventionally, GO and CS are the preferred compounds for this type of fabrication because of their hydrophilic nature. Nevertheless, when they are mixed together, the occurrence of ionic complexation (−COO− H3+ N−R) between the negatively charged carboxylate ions of GO and the positively charged protonated amines of CS create extreme membrane aggregation. Hydrothermal reduction is useful for preventing undesired ionic complexation from mixing rGO and CS because it can remove most carboxylate ions from GO. Consequently, the hydrophilic CS molecular chain is inserted in between the rGO laminates, improving the dispersion and enabling the rGO/CS to stack-up and self-assemble into a lamellar structure. Furthermore, excellent methanol dehydration can be observed through pervaporation, which is attributed to the selective water channels formed in the rGO laminates.

Background Coronary artery calcium score (CACS) is a well-established test for risk stratifying asymptomatic patients for overall cardiovascular or coronary events. However; the prognostic value for incident stroke remains controversial. The objective of this study was to investigate the predictive value of CACS obtained by non-contrast electrocardiogram-gated computed tomography for incident stroke. Methods We searched PubMed, EMBASE, Cochrane databases for prospective longitudinal studies of CACS which reported the incidence of stroke. Incidence of stroke was compared in patients with and without coronary calcification. Results Three studies evaluated 13,262 asymptomatic patients (mean age=60years, 50% men) without apparent cardiovascular diseases. During a follow-up of 7.2years (median 5years, range 4.4–9.5years, 95,434patient-years), the overall pooled incidence of stroke was 0.26%/year. The pooled risk ratio of CACS>0 for incident stroke was 2.95 (95% CI: 2.18–4.01, p 2 =0%). The pooled incidence rate of stroke categorized by CACS was 0.12%/year for CACS 0, 0.26%/year for CACS 1–99, 0.41%/year for CACS 100–399 and 0.70%/year for CACS ≥400. Conclusions In asymptomatic patients without apparent cardiovascular diseases, the incidence of stroke was overall low. The presence and severity of coronary artery calcification were associated with incident stroke over mid-long term follow-up.

The number of left ventricular assist device implants has increased significantly in the last decade. Left ventricular assist device (LVAD) optimization, trouble-shooting complications, and surgical planning require a multi-modality imaging approach. Echocardiography remains the imaging modality of choice, particularly for physiological evaluation but accurate anatomical evaluation of the entirety of the LVAD is often challenging if not impossible. Cardiac computed tomography (CCT) offers additional information that is valuable in taking care of these complex patients. The purpose of this review is to understand the nuances of LVAD imaging and areas where CCT can aid LVAD evaluation and management. CCT has a well-established role in trouble-shooting complications particularly inflow and outflow cannula-related anatomic complications from suction and kinking. Even though the literature is scarce, there is evolving data to suggest that adverse inflow and outflow cannula positions may result in unfavorable outcomes. There is more interest in novel mechanisms of device implantation and planning for which data set from CCT is ideal. Functional evaluation of the right ventricle with CCT is becoming more sophisticated and maybe particularly useful in this patient population. Development in CCT technology has helped minimize safety concerns and improved image quality with reduction in LVAD-related artifacts. CCT is an important adjunct modality to echocardiography for patients with LVAD. Information obtained from CCT may help our understanding of LVAD and in turn help reduce and managed LVAD-related complications.

A microwave-assisted hydrothermal method has been developed as an efficient approach to readily induce phase transition of titanate assemblies in conjunction with decoration of Cu2O clusters on the surface. The influence of Cu2+ ions on the hydrothermally induced structural evolution was examined, and the roles of heterojunctions in the resulting composites in charge separation for improved photocatalytic activity were clarified. Hierarchical titanate assemblies with high adsorption capacity for Cu2+ ions (95.7 mg/g) were prepared from a low alkaline condition. Microwave-assisted hydrothermal treatment was then used to transform the adsorbents into Cu2O/titanate/titania photocatalysts in 20 min via inducing titanate-to-titania and Cu2+-to-Cu2O dual transitions. While tubular architecture was maintained in the composites, the Cu2O clusters highly dispersed on the surface. Adsorbed Cu2+ ions have been found to retard the titanate-to-titania transformation locally, thus leading to Cu2O/titanate/titania heter...

BACKGROUND Transesophageal echocardiography (TEE) is recommended for diagnosis in patients suspected of prosthetic valve dysfunction, but could be limited in its ability to identify the etiology of these dysfunctions and to assess extracardiac structures. Our objective is to examine the usefulness of multidetector computed tomography (MDCT) in establishing the etiology of the dysfunctions and its clinical utility in preoperative assessment in these patients. METHODS Twenty-two prosthetic heart valves from 20 consecutive patients who had a preoperative MDCT and underwent redo prosthetic valve procedures from December 2008 to February 2013 were examined retrospectively. Results from MDCT and TEE were compared to intraoperative findings. Extravalvular MDCT findings including coronary artery/bypass graft, high-risk features for reoperative cardiac surgery, and extracardiac findings were also assessed. RESULTS MDCT correctly identified 15 valve regurgitation and seven valve obstructions compared to intraoperative findings. Both TEE and MDCT were able to correctly identify the etiologies in 93% (14/15) of regurgitant valves. However, MDCT was better able to identify the etiology of obstructive valves than TEE (86% [6/7] vs. 43% [3/7]) compared to intraoperative findings. In patients who had preoperative invasive angiography, MDCT correctly identified two patients with significant coronary artery disease (CAD) and ruled out 11 without significant CAD. Furthermore, MDCT detected five high-risk features for postoperative complications and eight clinically relevant extracardiac findings. CONCLUSIONS MDCT displayed comparable or better diagnostic performance than TEE for identifying the type of dysfunction and its etiology, as well as providing additional coronary and other extravalvular evaluations useful for preoperative planning.

The purpose of this study was to determine whether stress myocardial perfusion (SPECT) optimized with stress-only (SO) imaging is comparable to cardiac CT angiography (CTA) for evaluating patients with acute chest pain (ACP).This was a prospective randomized observational study in 598 ACP patients who underwent CTA versus SPECT. The primary endpoint was length of hospital stay, and secondary endpoints were test feasibility, time to diagnosis, diagnostic accuracy, radiation exposure, and overall cost. Median follow-up was 6.5 mo, with a 3.8% cardiac event rate defined as death or an acute coronary syndrome.Of 2,994 patients screened, 1,703 (56.9%) were not candidates for CTA because of prior cardiac disease (41%) or imaging contraindications (16%). Time to diagnosis (8.1 ± 8.5 vs. 9.4 ± 7.4 h) and length of hospital stay (19.7 ± 27.8 vs. 23.5 ± 34.4 h) were significantly shorter with CTA than with SPECT (P = 0.002). However, time to diagnosis (7.0 ± 6.2 vs. 6.8 ± 5.9 h, P = 0.20), length of stay (15.5 ± 17.2 vs. 16.7 ± 15.3 h, P = 0.36), and hospital costs ($4,242 ± $3,871 vs. $4,364 ± 1781, P = 0.86) were comparable with CTA versus SO SPECT, respectively. SO was also superior to conventional SPECT regarding all of the above metrics and significantly reduced radiation exposure (5.5 ± 4.4 vs. 12.5 ± 2.7 mSv, P0.0001).Stress SPECT when optimized with SO imaging is similar to CTA in time to diagnosis, length of hospital stay, and cost, with improved prognostic accuracy and less radiation exposure. Our results emphasize the importance of SO imaging, particularly in low-intermediate-risk emergency room patients who are a population likely to have a normal test result.

The objective of this study was to examine prevalence and clinical implications of subclinical coronary artery disease (CAD) detected by coronary artery calcium score (CACS) testing in patients with atrial fibrillation (AF). CACS was assessed in patients without history of CAD undergoing catheter ablation of AF. Age- and gender-matched patients with normal sinus rhythm (NSR) presenting with chest pain served as controls. Predicted arterial age using the Multi-Ethnic Study of Atherosclerosis registry was also compared to the chronologic age. A total of 860 patients (430 AF and 430 NSR, age 63 ± 10 years, 65% men) were included. Subclinical CAD prevalence (CACS >0) was 74% (319 of 430) in the AF group. Compared to the patients with NSR, patients with AF had higher prevalence of Subclinical CAD (74% vs 63%; p

Paravalvular leaks (PVL) occur in 2–12% of patients after mitral valve replacement and in 1–5% after aortic valve replacement 1,2 and can cause heart failure and/or hemolytic anemia. Redo surgery h...

Purpose of review Chest pain and myocardial ischemia are common features in patients with hypertrophic cardiomyopathy (HCM). This review addresses diagnostic roles of computed tomography and nuclear stress testing (NST) in patients with HCM. Recent findings Current evidence showed the limitation of NST in the diagnosis of epicardial coronary artery stenosis due to the prevalent microvascular dysfunction. In this context, the excellent negative predictive value of coronary computed tomography angiography (CCTA) makes it very attractive to serve as a gatekeeper to invasive angiography in low-risk symptomatic patients, either as the first noninvasive imaging test of choice or after the presence of perfusion defect seen in NST. Furthermore, the identification of coronary atherosclerosis process in the absence of obstructive lesion could have impacts on the management of risk factors for coronary artery disease. We also propose an algorithm for evaluation of ischemia in HCM patients based on the recent evidence. Summary In low-intermediate-risk symptomatic patients with HCM, both NST and CCTA are acceptable diagnostic tools for the evaluation of myocardial ischemia. In the presence of nuclear perfusion defect, CCTA can be used to rule out significant epicardial stenosis. Presence of significant major epicardial artery stenosis on CCTA or high-risk patients could be considered for invasive angiography.

To investigate incidence and timing, risk factors, prognostic significance, and electrophysiological mechanisms of atrial arrhythmia (AA) after lung transplantation.Although new-onset AA is common after thoracic surgery and is associated with poorer outcomes, prognostic and mechanistic data is sparse in lung transplant populations.A total of 293 consecutive isolated lung transplant recipients without known AA were retrospectively reviewed. Mean follow-up was 28±17 months. Electrophysiology studies (EPS) were performed in 25 patients with AA.The highest incidence of new-onset AA after lung transplantation occurred within 30 days postoperative AA, (25 % of all patients). In multivariable analysis, postoperative AA was associated with double lung transplantation (OR 2.79; p=0.005) and lower mean pulmonary artery pressure (OR 0.95; p=0.027). Patients with postoperative AA had longer hospital stays (21 days vs 12 days; p0.001). Postoperative AA was independently associated with late AA (HR 13.52; p0.001) but not mortality (HR 1.55; p=0.14). In EPS, there were 14 patients with atrial flutter alone and 11 with atrial flutter and fibrillation. Of all EPS patients, 20 (80%) had multiple AA mechanisms, including peritricuspid flutter (48%), perimitral flutter (36%), right atrial incisional reentry (24%), focal tachycardia from recipient pulmonary vein (PV) antrum (32 %), focal PV fibrillation (24%), and left atrial roof flutter (20%). Left atrial mechanisms were present in 80% (20/25) of EPS patients and originated from the anastomotic PV antrum.Postoperative AA was independently associated with longer length of stay and late AA but not mortality. Pleomorphic PV antral arrhythmogenesis from native PV antrum is the main cause of AA after lung transplantation.

Transcatheter mitral valve-in-valve implantation (TMVIV) is an option for patients with mitral prosthetic valve dysfunction who are at high risk for surgical valve replacement. Efficacy and safety of TMVIV is at its infancy. We report a high-risk symptomatic dialysis-dependent end-stage renal disease patient with severe bioprosthetic mitral valve stenosis who had TMVIV performed successfully.

Objectives This prospective, observational study in 988 asymptomatic or symptomatic low-risk patients without prior coronary artery disease was conducted to define the relative value of coronary artery calcium score (CACS), exercise treadmill testing (ETT), and stress myocardial perfusion single-photon emission computed tomography (SPECT) variables in predicting long-term risk stratification. Background CACS, ETT, and stress myocardial perfusion SPECT results predict patients9 outcome. There are currently no data comparing their relative value in long-term risk stratification. Methods Patients were stratified by Framingham risk score (FRS), with a median follow-up of 6.9 years. Cardiac events were defined as a composite of cardiac death, nonfatal myocardial infarction, and the need for coronary revascularization. Most patients (87%) were considered appropriate candidates for functional testing as defined by current appropriate use criteria. Results The long-term cardiac event rate was 11.2% (1.6% per year). Multivariate risk predictors in all patients and in the appropriate use cohort were abnormal SPECT (hazard ratio [HR]: 1.83 and 1.99), ETT ischemia (HR: 1.70 and 1.76), decreasing exercise capacity (HR: 1.11 and 1.17), decreasing Duke treadmill score (HR: 1.07 for both), and CACS severity (HR: 1.29 for both), respectively. Throughout the 10-year follow-up, CACS improved risk prediction, with event rates ranging from 0.6% per year (CACS ≤10) to 3.7% per year (CACS >400) (p Conclusions CACS significantly improved long-term risk stratification beyond FRS, ETT, and SPECT results across the spectrum of clinical risk and importantly even among those who are currently considered appropriate candidates for functional testing or have low-risk functional test results. Our findings support CACS as a first-line test over ETT or SPECT for accurately assessing long-term risk in such patients.