Current complications of diagnostic and therapeutic cardiac catheterization

Aortic Stenosis: Haemodynamic Benchmark and Metric Reliability Study

Aortic stenosis is a condition which is fatal if left untreated. Novel quantitative imaging techniques which better characterise transvalvular pressure drops are being developed but require refinement and validation. A customisable and cost-effective workbench valve phantom circuit capable of replicating valve mechanics and pathology was created. The reproducibility and relationship of differing haemodynamic metrics were assessed from ground truth pressure data alongside imaging compatibility. The phantom met the requirements to capture ground truth pressure data alongside ultrasound and magnetic resonance image compatibility. The reproducibility was successfully tested. The robustness of three different pressure drop metrics was assessed: whilst the peak and net pressure drops provide a robust assessment of the stenotic burden in our phantom, the peak-to-peak pressure drop is a metric that is confounded by non-valvular factors such as wave reflection. The peak-to-peak pressure drop is a metric that should be reconsidered in clinical practice. The left panel shows manufacture of low cost, functional valves. The central section demonstrates circuit layout, representative MRI and US images alongside gross valve morphologies. The right panel shows the different pressure drop metrics that were assessed for reproducibility.

Deep learning for myocardial ischemia auxiliary diagnosis using CZT SPECT myocardial perfusion imaging

BACKGROUND

The World Health Organization reported that cardiovascular disease is the most common cause of death worldwide. On average, one person dies of heart disease every 26 min worldwide. Deep learning approaches are characterized by the appropriate combination of abnormal features based on numerous annotated images. The constructed convolutional neural network (CNN) model can identify normal states of reversible and irreversible myocardial defects and alert physicians for further diagnosis.

METHODS

Cadmium zinc telluride single-photon emission computed tomography myocardial perfusion resting-state images were collected at Chang Gung Memorial Hospital, Kaohsiung Medical Center, Kaohsiung, Taiwan, and were analyzed with a deep learning convolutional neural network to classify myocardial perfusion images for coronary heart diseases.

RESULTS

In these grey-scale images, the heart blood flow distribution was the most crucial feature. The deep learning technique of You Only Look Once was used to determine the myocardial defect area and crop the images. After surrounding noise had been eliminated, a three-dimensional CNN model was used to identify patients with coronary heart diseases. The prediction area under the curve, accuracy, sensitivity, and specificity was 90.97, 87.08, 86.49, and 87.41%, respectively.

CONCLUSION

Our prototype system can considerably reduce the time required for image interpretation and improve the quality of medical care. It can assist clinical experts by offering accurate coronary heart disease diagnosis in practice.

Evaluation of aortic stenosis: From Bernoulli and Doppler to Navier-Stokes

Uni-dimensional Doppler echocardiography data provide the mainstay of quantative assessment of aortic stenosis, with the transvalvular pressure drop a key indicator of haemodynamic burden. Sophisticated methods of obtaining velocity data, combined with improved computational analysis, are facilitating increasingly robust and reproducible measurement. Imaging modalities which permit acquisition of three-dimensional blood velocity vector fields enable angle-independent valve interrogation and calculation of enhanced measures of the transvalvular pressure drop. This manuscript clarifies the fundamental principles of physics that underpin the evaluation of aortic stenosis and explores modern techniques that may provide more accurate means to grade aortic stenosis and inform appropriate management.

Inverse problems in blood flow modeling: A review

Mathematical and computational modeling of the cardiovascular system is increasingly providing non-invasive alternatives to traditional invasive clinical procedures. Moreover, it has the potential for generating additional diagnostic markers. In blood flow computations, the personalization of spatially distributed (i.e., 3D) models is a key step which relies on the formulation and numerical solution of inverse problems using clinical data, typically medical images for measuring both anatomy and function of the vasculature. In the last years, the development and application of inverse methods has rapidly expanded most likely due to the increased availability of data in clinical centers and the growing interest of modelers and clinicians in collaborating. Therefore, this work aims to provide a wide and comparative overview of literature within the last decade. We review the current state of the art of inverse problems in blood flows, focusing on studies considering fully dimensional fluid and fluid-solid models. The relevant physical models and hemodynamic measurement techniques are introduced, followed by a survey of mathematical data assimilation approaches used to solve different kinds of inverse problems, namely state and parameter estimation. An exhaustive discussion of the literature of the last decade is presented, structured by types of problems, models and available data.

Coronary angiography in acute ischemic stroke patients: frequency and determinants of pathological findings in a multicenter cohort study

Background

Myocardial injury as indicated by cardiac troponin elevation is associated with poor prognosis in acute stroke patients. Coronary angiography (CAG) is the diagnostic gold-standard to rule-out underlying obstructive coronary artery disease (CAD) in these patients. However, weighing risks and benefits of coronary angiography (CAG) against each other is particularly challenging, because stroke patients undergoing CAG may have a higher risk for secondary intracranial bleeding. Current guidelines remain vague. Thus, the aim of this study was to analyze frequency of pathological findings of CAG and associated clinical factors.

Methods

We analyzed indications and frequency of CAG performed in acute ischemic stroke patients in clinical routine in two European tertiary care hospitals from 2011 to 2018. All data were obtained retrospectively. Multiple logistic regression analyses were performed to identify variables associated with absence of obstructive coronary artery disease defined as presence of at least one coronary vessel stenosis ≥ 50%.

Results

A total of 139 AIS patients underwent CAG. Frequent indications for CAG were suspected acute coronary syndrome (N = 114) or scheduled cardiac surgery (N = 25). Acute coronary stenting was applied in 51/139 patients. Among patients with suspected acute coronary syndrome, no obstructive CAD was found in 27/114 patients. Absence of obstructive CAD was associated with insular cortex lesions, no clinical symptoms for ACS, less than three cardiovascular risk factors, younger age and normal wall motion.

Conclusion

Several variables suggest absence of CAD in AIS patients and may help in clinical decision making in stroke patients with myocardial injury.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-022-11001-5.

Noninvasive quantification of cerebrovascular pressure changes using 4D Flow MRI

PURPOSE

Hemodynamic alterations are indicative of cerebrovascular disease. However, the narrow and tortuous cerebrovasculature complicates image-based assessment, especially when quantifying relative pressure. Here, we present a systematic evaluation of image-based cerebrovascular relative pressure mapping, investigating the accuracy of the routinely used reduced Bernoulli (RB), the extended unsteady Bernoulli (UB), and the full-field virtual work-energy relative pressure ( ν WERP) method.

METHODS

Patient-specific in silico models were used to generate synthetic cerebrovascular 4D Flow MRI, with RB, UB, and ν WERP performance quantified as a function of spatiotemporal sampling and image noise. Cerebrovascular relative pressures were also derived in 4D Flow MRI from healthy volunteers ( n = 8 ), acquired at two spatial resolutions (dx = 1.1 and 0.8 mm).

RESULTS

The in silico analysis indicate that accurate relative pressure estimations are inherently coupled to spatial sampling: at dx = 1.0 mm high errors are reported for all methods; at dx = 0.5 mm ν WERP recovers relative pressures at a mean error of 0.02 ± 0.25 mm Hg, while errors remain higher for RB and UB (mean error of -2.18 ± 1.91 and -2.18 ± 1.87 mm Hg, respectively). The dependence on spatial sampling is also indicated in vivo, albeit with higher correlative dependence between resolutions using ν WERP (k = 0.64, R2 = 0.81 for dx = 1.1 vs. 0.8 mm) than with RB or UB (k = 0.04, R2 = 0.03, and k = 0.07, R2 = 0.07, respectively).

CONCLUSION

Image-based full-field methods such as ν WERP enable cerebrovascular relative pressure mapping; however, accuracy is directly dependent on utilized spatial resolution.

Non-invasive estimation of relative pressure for intracardiac flows using virtual work-energy

Intracardiac blood flow is driven by differences in relative pressure, and assessing these is critical in understanding cardiac disease. Non-invasive image-based methods exist to assess relative pressure, however, the complex flow and dynamically moving fluid domain of the intracardiac space limits assessment. Recently, we proposed a method, νWERP, utilizing an auxiliary virtual field to probe relative pressure through complex, and previously inaccessible flow domains. Here we present an extension of νWERP for intracardiac flow assessments, solving the virtual field over sub-domains to effectively handle the dynamically shifting flow domain. The extended νWERP is validated in an in-silico benchmark problem, as well as in a patient-specific simulation model of the left heart, proving accurate over ranges of realistic image resolutions and noise levels, as well as superior to alternative approaches. Lastly, the extended νWERP is applied on clinically acquired 4D Flow MRI data, exhibiting realistic ventricular relative pressure patterns, as well as indicating signs of diastolic dysfunction in an exemplifying patient case. Summarized, the extended νWERP approach represents a directly applicable implementation for intracardiac flow assessments.

Multimodality Tachycardia-Induced Stress Testing Predicts a Low-Risk Group for Early Cardiovascular Mortality After Renal Transplantation

Background

Cardiovascular events remain a major cause of death in kidney transplant recipients. The optimal noninvasive workup to prevent peritransplant cardiac mortality remains contentious.

Methods

We conducted a retrospective analysis to assess the renal transplantation cardiovascular assessment protocol within a single-center population over a 5-year period. Asymptomatic patients aged less than 45 years with no history of cigarette smoking, without diabetes mellitus, and dialysis-dependent for less than 24 months did not undergo cardiac testing before listing. All other asymptomatic patients underwent a noninvasive, tachycardia-induced stress test, where a target heart rate of 85% predicted for age and gender was required. The primary endpoints were rates of acute myocardial infarction (AMI) and cardiovascular death at 30 days after renal transplantation.

Results

Between 2015 and 2019, 380 recipients underwent cardiac evaluation: 79 (20.8%) were deemed low cardiovascular risk and placed on the renal transplant waitlist without further assessment; 270 (71.1%) underwent a tachycardia-induced stress test; and 31 (8.1%) were deemed high risk and proceeded directly to invasive coronary angiography (ICA). In the 5-year follow-up, 3 patients (0.8%) experienced an AMI 30 days after renal transplantation, all of which occurred in the high-risk “direct to ICA” cohort. No events were documented in the low-risk cohort or in patients who had a negative tachycardia-induced stress test. There were no cardiovascular deaths within 30 days after transplantation.

Conclusion

A negative tachycardia-induced cardiac stress test, achieving 85% of predicted heart rate, was associated with a 0% AMI rate and no cardiovascular deaths at 30 days after renal transplantation.

Relationship between Semi-Quantitative Parameters of Thallium-201 Myocardial Perfusion Imaging and Coronary Artery Disease

This study aimed to investigate the diagnostic performance of semi-quantitative parameters of thallium-201 myocardial perfusion imaging (MPI) for coronary artery disease (CAD). From January to December 2017, patients were enrolled who had undergone Tl-201 MPI and received cardiac catheterization for coronary artery disease within three months of MPI. Receiver operating characteristics (ROC) analysis was used to determine the optimal cutoff values of semi-quantitative parameters. A comparison of the sensitivity and specificity of these parameters based on different subgroupings was further performed. A total of 130 patients were enrolled for further analysis. Among the collected parameters, the stress total perfusion deficit (sTPD) had the highest value of the area under curve (0.813) under the optimal cutoff value of 3.5%, with a sensitivity and specificity of 73.5% and 74.5%, respectively (p = 0.0000), for the diagnosis of CAD. With further subgrouping analysis based on history of diabetes or dyslipidemia, the sensitivity and specificity showed similar results. Based on the currently collected data and image acquisition conditions, the sTPD parameter has a clinical role for the diagnosis of CAD with a cutoff value of 3.5%.

Non-invasive estimation of relative pressure in turbulent flow using virtual work-energy

Vascular pressure differences are established risk markers for a number of cardiovascular diseases. Relative pressures are, however, often driven by turbulence-induced flow fluctuations, where conventional non-invasive methods may yield inaccurate results. Recently, we proposed a novel method for non-turbulent flows, νWERP, utilizing the concept of virtual work-energy to accurately probe relative pressure through complex branching vasculature. Here, we present an extension of this approach for turbulent flows: νWERP-t. We present a theoretical method derivation based on flow covariance, quantifying the impact of flow fluctuations on relative pressure. νWERP-t is tested on a set of in-vitro stenotic flow phantoms with data acquired by 4D flow MRI with six-directional flow encoding, as well as on a patient-specific in-silico model of an acute aortic dissection. Over all tests νWERP-t shows improved accuracy over alternative energy-based approaches, with excellent recovery of estimated relative pressures. In particular, the use of a guaranteed divergence-free virtual field improves accuracy in cases where turbulent flows skew the apparent divergence of the acquired field. With the original νWERP allowing for assessment of relative pressure into previously inaccessible vasculatures, the extended νWERP-t further enlarges the method's clinical scope, underlining its potential as a novel tool for assessing relative pressure in-vivo.

A new machine learning technique for an accurate diagnosis of coronary artery disease

BACKGROUND AND OBJECTIVE

Coronary artery disease (CAD) is one of the commonest diseases around the world. An early and accurate diagnosis of CAD allows a timely administration of appropriate treatment and helps to reduce the mortality. Herein, we describe an innovative machine learning methodology that enables an accurate detection of CAD and apply it to data collected from Iranian patients.

METHODS

We first tested ten traditional machine learning algorithms, and then the three-best performing algorithms (three types of SVM) were used in the rest of the study. To improve the performance of these algorithms, a data preprocessing with normalization was carried out. Moreover, a genetic algorithm and particle swarm optimization, coupled with stratified 10-fold cross-validation, were used twice: for optimization of classifier parameters and for parallel selection of features.

RESULTS

The presented approach enhanced the performance of all traditional machine learning algorithms used in this study. We also introduced a new optimization technique called N2Genetic optimizer (a new genetic training). Our experiments demonstrated that N2Genetic-nuSVM provided the accuracy of 93.08% and F1-score of 91.51% when predicting CAD outcomes among the patients included in a well-known Z-Alizadeh Sani dataset. These results are competitive and comparable to the best results in the field.

CONCLUSIONS

We showed that machine-learning techniques optimized by the proposed approach, can lead to highly accurate models intended for both clinical and research use.

Decision analytic modeling was useful to assess the impact of a prediction model on health outcomes before a randomized trial

OBJECTIVE

To demonstrate how decision analytic models (DAMs) can be used to quantify impact of using a (diagnostic or prognostic) prediction model in clinical practice and provide general guidance on how to perform such assessments.

STUDY DESIGN AND SETTING

A DAM was developed to assess the impact of using the HEART score for predicting major adverse cardiac events (MACE). Impact on patient health outcomes and health care costs was assessed in scenarios by varying compliance with and informed deviation (ID) (using additional clinical knowledge) from HEART score management recommendations. Probabilistic sensitivity analysis was used to assess estimated impact robustness.

RESULTS

Impact of using the HEART score on health outcomes and health care costs was influenced by an interplay of compliance with and ID from HEART score management recommendations. Compliance of 50% (with 0% ID) resulted in increased missed MACE and costs compared with usual care. Any compliance combined with at least 50% ID reduced both costs and missed MACE. Other scenarios yielded a reduction in missed MACE at higher costs.

CONCLUSION

Decision analytic modeling is a useful approach to assess impact of using a prediction model in practice on health outcomes and health care costs. This approach is recommended before conducting an impact trial to improve its design and conduct.

Estimation of Cardiovascular Relative Pressure Using Virtual Work-Energy

Many cardiovascular diseases lead to local increases in relative pressure, reflecting the higher costs of driving blood flow. The utility of this biomarker for stratifying the severity of disease has thus driven the development of methods to measure these relative pressures. While intravascular catheterisation remains the most direct measure, its invasiveness limits clinical application in many instances. Non-invasive Doppler ultrasound estimates have partially addressed this gap; however only provide relative pressure estimates for a range of constricted cardiovascular conditions. Here we introduce a non-invasive method that enables arbitrary interrogation of relative pressures throughout an imaged vascular structure, leveraging modern phase contrast magnetic resonance imaging, the virtual work-energy equations, and a virtual field to provide robust and accurate estimates. The versatility and accuracy of the method is verified in a set of complex patient-specific cardiovascular models, where relative pressures into previously inaccessible flow regions are assessed. The method is further validated within a cohort of congenital heart disease patients, providing a novel tool for probing relative pressures in-vivo.

Uncertainty Quantification for Non-invasive Assessment of Pressure Drop Across a Coarctation of the Aorta Using CFD

PURPOSE

Numerical assessment of the pressure drop across an aortic coarctation using CFD is a promising approach to replace invasive catheter-based measurements. The aim of this study was to investigate and quantify the uncertainty of numerical calculation of the pressure drop introduced during two essential steps of medical image processing: segmentation of the patient-specific geometry and measurement of patient-specific flow rates from 4D-flow-MRI.

METHODS

Based on the baseline segmentation, geometries with different stenosis diameters were generated for a sample of ten patients. The pressure drop generated by these geometries was calculated for different volume flow rates using computational fluid dynamics. Based on these simulations, a second order polynomial fit was calculated. Based on these polynomial fits an uncertainty of pressure drop calculation was quantified.

RESULTS

The calculated pressure drop values varied strongly between the patients. In four patients, pressure drops above and below the clinical threshold of 20 mmHg were found. The median standard deviation of the pressure drop was 2.3 mmHg. The sensitivity of the pressure drop toward changes in the volume flow rate or the stenosis geometry varied between patients.

CONCLUSION

The uncertainty of numerical pressure drop calculation introduced by uncertainties during image segmentation and measurement of volume flow rates was comparable to the uncertainty of pressure drop measurements using invasive catheterization. However, in some patients this uncertainty would have led to different treatment decision. Therefore, patient-specific uncertainty assessment might help to better understand the reliability of a numerically calculated biomarker as the pressure drop across an aortic coarctation.

Are iso-osmolar, as compared to low-osmolar, contrast media cost-effective in patients undergoing cardiac catheterization? An economic analysis

PURPOSE

Contrast-induced acute kidney injury is a prominent complication following cardiac catheterization, though the risk has progressively decreased in recent times with appropriate risk stratification and use of safer contrast agents. Despite data supporting further lowering of risk with the iso-osmolar agent, iodixanol, uptake has lagged, perhaps due to increased upfront cost of this agent. We undertook an economic analysis to estimate the cost-effectiveness of a strategy utilizing iodixanol compared to using a low-osmolar contrast agent.

METHODS

We created a Markov model to evaluate the two strategies, and included a differential relative risk of contrast-induced acute kidney injury, based on a systematic review of the literature. Downstream clinical events, including need for dialysis and mortality, were modeled using data from existing published literature. A third-party payer perspective was utilized for the analysis and presentation of the primary economic analysis.

RESULTS

The strategy of using iodixanol dominated in both the low-risk and high-risk base case analyses. However, the difference was quite small in the low-risk scenario (lifetime cost: C$678,034 vs. C$678,059 and life expectancy: 19.80 vs. 19.72 years). The difference was more marked (life expectancy 15.65 vs. 14.15 years and cost C$680,989 vs. C$682,023) in the high-risk case analysis. This was robust across most of the variables tested in sensitivity analyses.

CONCLUSION

The use of iodixanol, compared with low-osmolar contrast agents, for cardiac catheterization, results in a small benefit clinical outcomes, and in a savings in direct healthcare costs. Overall, our analysis supports the use of iodixanol for cardiac catheterization, especially in patients at high risk of acute kidney injury.

Validity of algorithm for estimating left sided filling pressures on echocardiography in a population referred for pulmonary arterial hypertension

The determination of LV filling pressure is integral to the diagnosis of pulmonary arterial hypertension (PAH). The American Society of Echocardiography (ASE) has devised algorithms for their estimation. We aimed to test these algorithms in a population referred for suspected PAH. In our retrospective study, we evaluated the accuracy of the ASE Algorithms compared to right heart catheterization done within three months, in patients seen during 2006–2014. All echocardiograms were classified as showing normal, elevated or indeterminate filling pressures. Those with indeterminate pressures were excluded. We evaluated the diagnostic properties of this algorithm to predict a pulmonary artery wedge pressure (PAWP) and left ventricular end diastolic pressure (LVEDP) >15 mmHg. A total of 94 patients were included. The ASE algorithms yielded indeterminate results in 50 (53.2%) patients. This occurred more commonly in older patients and patients with cardiovascular comorbidities. The algorithm had a high sensitivity for predicting an elevated PAWP at 89.5% (95% confidence interval [CI] = 66.9–98.7) and an elevated LVEDP at 100% (95% CI = 76.8–100). The algorithm had a negative predictive value of 81.8% and 100% for predicting an elevated PAWP (95% CI = 52.4–94.8) and LVEDP, respectively, but a poor positive predictive value. The ASE algorithm for predicting LV filling pressures often cannot be applied in populations with suspected PAH. When they are interpretable, they have a high negative predictive value for elevated PAWP and LVEDP. We recommend caution when using these algorithms in populations with suspected PAH.

Effective Heart Disease Detection Based on Quantitative Computerized Traditional Chinese Medicine Using Representation Based Classifiers

At present, heart disease is the number one cause of death worldwide. Traditionally, heart disease is commonly detected using blood tests, electrocardiogram, cardiac computerized tomography scan, cardiac magnetic resonance imaging, and so on. However, these traditional diagnostic methods are time consuming and/or invasive. In this paper, we propose an effective noninvasive computerized method based on facial images to quantitatively detect heart disease. Specifically, facial key block color features are extracted from facial images and analyzed using the Probabilistic Collaborative Representation Based Classifier. The idea of facial key block color analysis is founded in Traditional Chinese Medicine. A new dataset consisting of 581 heart disease and 581 healthy samples was experimented by the proposed method. In order to optimize the Probabilistic Collaborative Representation Based Classifier, an analysis of its parameters was performed. According to the experimental results, the proposed method obtains the highest accuracy compared with other classifiers and is proven to be effective at heart disease detection.

Intravenous Contrast-Induced Nephropathy-The Rise and Fall of a Threatening Idea

Contrast-induced nephropathy (CIN) has been considered to be a cause of renal failure for over 50 years, but careful review of past and recent studies reveals the risks of CIN to be overestimated. Older studies frequently cited the use of high-osmolality contrast media, which have since been replaced by low-osmolality contrast media, which have lower risks for nephropathy. In addition, literature regarding CIN typically describes the incidence following cardiac angiography, whereas the risk of CIN from intravenous injection is much lower. Most of the early published literature also lacked appropriate control groups to compare to those that received iodinated contrast, and thus attributed rises in creatinine to intravenous contrast without considering normal creatinine fluctuations (frequent in patients with kidney disease) and other acute pathologic states such as hypotension or nephrotoxic drug administration. The aim of this paper is to review the literature detailing CIN risk, discuss why CIN risk is often overestimated and how withholding contrast can lead to misdiagnosis and delay in appropriate patient management.

Integrate imaging approach for minimally invasive and robotic procedures

Over the past two decades, robotic and minimally invasive cardiac surgery has been continuously refined and is currently an alternative to traditional open-heart surgery for some patients. The parallel evolution of imaging modalities has made robotic surgery safer and more efficient. Here, we review the pre- and post-operative use of computed tomography (CT) in minimally invasive and robotic cardiac procedures.

Predictors of common femoral artery access site complications in patients on oral anticoagulants and undergoing a coronary procedure

Background

It is unclear whether patients on oral anticoagulants (OAC) undergoing a procedure using common femoral artery access have higher adverse events when compared to patients who are not anticoagulated at the time of the procedure.

Methods

We retrospectively reviewed data from consecutive patients who underwent a cardiac procedure at a tertiary medical center. Patients were considered (group A) fully or partially anticoagulated if they had an international normalized ratio (INR) ≥1.6 on the day of the procedure or were on warfarin or new OAC within 48 h and 24 h of the procedure, respectively. The nonanticoagulated group (group B) had an INR <1.6 or had stopped their warfarin and new OAC >48 h and >24 h preprocedure, respectively. The index primary end point of the study was defined as the composite end point of major bleeding, vascular complications, or cardiovascular-related death during index hospitalization. The 30-day primary end point was defined as the occurrence of the index primary end point and up to 30 days postprocedure.

Results

A total of 779 patients were included in this study. Of these patients, 27 (3.5%) patients were in group A. The index primary end point was met in 11/779 (1.4%) patients. The 30-day primary composite end point was met in 18/779 (2.3%) patients. There was no difference in the primary end point at index between group A (1/27 [3.7%]) and group B (10/752 [1.3%]; P=0.3155) and no difference in the 30-day primary composite end point between group A (2/27 [7.4%]) and group B (16/752 [2.1%]; P=0.1313). Multivariable analysis showed that a low creatinine clearance (odds ratio [OR] =0.56; P=0.0200) and underweight patients (<60 kg; OR =3.94; P=0.0300) were independent predictors of the 30-day primary composite end point but not oral anticoagulation (P=0.1500).

Conclusion

Patients on OAC did not have higher 30-day major adverse events than those who were not anticoagulated at index procedure.

Non-invasive cardiac pacing with image-guided focused ultrasound

Currently, no non-invasive cardiac pacing device acceptable for prolonged use in conscious patients exists. High Intensity Focused Ultrasound (HIFU) can be used to perform remote pacing using reversibility of electromechanical coupling of cardiomyocytes. Here we described an extracorporeal cardiac stimulation device and study its efficacy and safety. We conducted experiments ex vivo and in vivo in a large animal model (pig) to evaluate clinical potential of such a technique. The stimulation threshold was determined in 10 different ex vivo hearts and different clinically relevant electrical effects such as consecutive stimulations of different heart chambers with a single ultrasonic probe, continuous pacing or the inducibility of ventricular tachycardia were shown. Using ultrasonic contrast agent, consistent cardiac stimulation was achievable in vivo for up to 1 hour sessions in 4 different animals. No damage was observed in inversion-recovery MR sequences performed in vivo in the 4 animals. Histological analysis revealed no differences between stimulated and control regions, for all ex vivo and in vivo cases.

Severe Coronary Artery Spasm with Anaphylactoid Shock Caused by Contrast Medium

This study reports 2 cases of severe coronary artery spasm with anaphylactoid shock caused by contrast medium. The first patient had anaphylactoid shock in response to contrast medium and severe coronary spasms of both the left anterior descending coronary artery and the left circumflex coronary artery. The patient developed ventricular arrhythmia and complete atrioventricular block following the severe coronary spasm. The second patient had a totally occluded right coronary artery, owing to a spasm after anaphylactoid shock. Anaphylactoid shock should always be considered when persistent shock is noted after the coronary artery spasm has been relieved.

Complications of Cardiac Catheterization: A Single-Center Study

In Turkey as well as in the whole world, cardiac catheterization is an invasive intervention that is being increasingly used both for diagnosis and treatment. With technological and pharmacologic development and experience, the indications for this intervention are ever increasing. This invasive intervention brings, of course, some complications with it. These may range from local ones to death. In this study the authors analyzed the local cardiac complications and those related to other systems that they encountered in 10,445 catheterizations conducted for diagnosis and treatment in their clinic over a 26-month period. They found the rate of all complications to be 3.54% (2.05% diagnostic, 9.1% therapeutic). Of these complications, 1.89% (0.80% diagnostic, 6.02% therapeutic) were cardiac, 1.27% (0.97% diagnostic, 2.4% therapeutic) local. They found that the ratios of death were 0.09% for diagnostic interventions, 1.13% for therapeutic interventions, and 0.31% altogether. In the diagnostic group 0.02% required urgent coronary bypass surgery, and 0.41% needed urgent coronary bypass surgery in the therapeutic group. In conclusion, despite the noticeable changes in patient profile and application, the ratios for cardiac catheterization have changed little over the years.

Unusual Retrograde Aortic Arch Dissection During Percutaneous Coronary Intervention

Coronary dissection is one of the most frequently occurring complications during coronary interventional procedures. However, extensive coronary dissection retrograde to the coronary sinus of Valsalva and to the arch of aorta is very rarely observed. The authors report a case of retrograde coronary dissection extending into the arch of aorta. Management and coronary angiography at 6-month follow-up are discussed.

A New Access Site Management Tool: The Angio-Seal™ Hemostatic Puncture Closure Device

Purpose:

Given the increasing number of percutaneously applied endovascular therapies, the incidence of access-related vascular complications can be expected to rise, particularly in association with those techniques requiring large sheaths or anticoagulation. The need exists for a safe, easy to use, and effective hemostatic technique to replace the labor-intensive method of manual compression.

Methods:

A bioabsorbable, sheath-delivered vascular closure device (Angio-Seal™) has been developed that deposits a small collagen plug within the arterial wall to mechanically seal the puncture defect. An anchor connected by suture to the plug is first deployed in the arterial lumen and pulled flush against the interior arterial wall to guard against intraluminal deposition of the collagen.

Results:

The Angio-Seal device was deployed successfully in 80 (96%) of 83 attempts involving common femoral arteries accessed for peripheral angioplasty (n = 30), coronary angiography (n = 30), and coronary angioplasty (n = 16). Three popliteal artery access sites and one femoropopliteal bypass graft were also treated. Hemostasis was immediate in 78 cases (98%); 2 sites required a 5-minute manual compression to effect a secure seal. Three devices failed to deploy, and manual pressure was used to close the puncture. Nondeployment did not cause any sequelae, and no complications were encountered with the technique.

Conclusions:

This novel vascular closure device is quick (< 1 minute application time) and simple to use, providing a positive seal of common femoral artery puncture sites for both peripheral and coronary interventions. It appears to be a reliable alternative to standard manual hemostasis.

Risk Factors for Groin Wound Infection After Femoral Artery Catheterization A Case-Control Study

Objective.

Groin wound infection (GWI) after femoral artery catheterization is unusual. However, several reports of GWI associated with the use of a Perclose device appear in the surgical literature.

Design.

A case-control study.

Setting.

We pooled 23 cases and 83 controls from a university hospital and a community medical center.

Patients.

A case was defined as a patient who developed a GWI after a femoral artery catheterization. At the university hospital, 3 controls were randomly selected from the at-risk population and matched to each case by time of procedure only (within 2 weeks). At the community medical center, 4 controls were selected and matched to each case by time of procedure (within 2 weeks), sex, and age (within 5 years).

Results.

We considered several covariates, including age, sex, body mass index, medical conditions, Perclose use, hematoma formation, and antithrombotic therapy. In a multivariate model, only hematoma formation (odds ratio, 68.8; 95% confidence interval, 12.1-391.4) and glycoprotein IIb/IIIa platelet inhibitor therapy (odds ratio, 6.1; 95% confidence interval, 1.1-33.6) were statistically significant predictors of GWI; Perclose use (odds ratio, 0.9; 95% confidence interval, 0.2-3.7) was not a statistically significant predictor of GWI. However, most of the hematomas (15/17) formed after procedures during which a Perclose device was used.

Conclusion.

Perclose use did not have any additional effect on GWI risk beyond the effect that hematoma formation had.

Why can't I see after my heart is fixed: a case series of ocular complications after cardiac intervention

Background

The purpose of this study was to report case series of retinal artery occlusion (RAO) as one of the significant complication post cardiac intervention.

Case presentation

We are reporting one case of branch RAO and one case of central RAO after percutaneous coronary intervention (PCI). In case 1, a 74-year-old gentleman with pre-existing diabetes mellitus and hypertension was electively admitted for PCI for coronary artery disease (CAD) in our centre (UKMMC). Few hours after the procedure, patient complained of sudden blurring of vision in the right eye. He was found to have branch retinal artery occlusion. In case 2, a 49-year-old gentleman presented with ST segment elevation myocardial infarction (STEMI) and had an emergency PCI performed 2 h upon admission. He noticed sudden dropped of vision in his right eye immediately after the procedure. He was diagnosed to have central retinal artery occlusion.

Conclusions

In conclusion, retinal artery occlusion is a possible complication post PCI. Patients need to be informed especially in high risk cases.

Percutaneous instillation of physiological saline solution for the treatment of femoral pseudoaneuryms

OBJECTIVE

To investigate the efficacy of para-aneurysmal saline injection for closure of postcatheterization pseudo-aneurysm (PA) at the vascular access site.

METHODS

Fifty-one consecutive patients with postcatheterization PA at the vascular access site were included to undergo percutaneous para-aneurysmal saline injection. In case of technical failure the day after, PA were treated by bovine thrombin injection. Anatomical properties of the PA were recorded as were details to injection.

RESULTS

Initially all patients exhibited success which was reduced to 43 % at day one. A saline volume of median 7 ml (interquartile range 6-8 ml) has been injected. The amount of injected saline was not different in patients with and without treatment success at day one (P = 0.6). Several anatomical properties of the PA exhibited marked differences in patients with or without success. The length (10.3 mm (7.8-12.0) vs. 12.5 mm (10.3-15.0); P = 0.009) and the angulation (110° (100-118) vs. 140° (129-146); P < 0.001) of the fistula/vessel axis was statistically different between groups. The peak systolic velocity failed to show significance with a tendency to higher values in the ineffective study group (P = 0.07). No peripheral complications occurred.

CONCLUSION

Para-aneurysmal saline injection may be a therapeutic alternative to percutaneous thrombin injection in patients exhibiting favorable anatomical properties.

Echocardiographic Assessment of Right Atrial Pressure in a Pediatric and Young Adult Population

Right atrial pressure (RAP) reflects right-sided cardiac hemodynamics and is useful in management of patients with cardiac and systemic disease. Studies in older adults demonstrated that inferior vena cava (IVC) diameter, IVC collapsibility index, hepatic vein systolic filling fraction (SFF), and right atrial volume (RAV) correlated with mean RAP at catheterization. This study aimed to assess the utility of echocardiographic parameters for assessment of RAP in children and young adults. Patients with pulmonary hypertension or heart transplantation undergoing right heart catheterization were recruited for this prospective observational pilot study. Transthoracic echocardiographic assessment of RAP was performed simultaneously with catheterization. For each parameter, three consecutive cardiac cycles were recorded. Long- and short-axis images of the IVC were obtained. RAV was assessed by area-length and biplane methods. IVC diameters and RAV were indexed to body surface area (BSA)(0.5) and (BSA)(1.4), respectively. Relationships between echocardiographic parameters and mean RAP were correlated using "Pearson's r." Fifty subjects aged 0.3-23 years (median 13, mean 12.3 ± 7 years) were enrolled. Mean RAP correlated modestly with RAV (r = 0.51, p < 0.001). Long-axis IVCmax (r = 0.30, p < 0.05) and tricuspid E wave velocity (r = 0.36, p < 0.01) also correlated with mean RAP. RV free wall tissue Doppler velocities, IVC collapsibility index, and hepatic vein SFF had no relation to mean RAP. In a pediatric and young adult population with pulmonary hypertension or heart transplantation, echocardiographic assessment of RAV and long-axis IVCmax provided a reasonable estimate of mean RAP. IVC collapsibility index and hepatic vein SFF demonstrated no association with mean RAP.

Systemic lupus erythematosus coronary vasculitis demonstrated on cardiac computed tomography

Coronary artery aneurysms are an uncommon manifestation of systemic lupus erythematosus (SLE), with only 14 cases reported previously in the literature. Herein, we report a 29-year-old woman with SLE who developed clinical and serologic evidence of an SLE flare and presented with chest pain and elevated serum troponin-T level. Cardiac computed tomography was performed and demonstrated fusiform aneurysmal enlargement of the proximal and middle portions of the coronary arteries and a beaded appearance of the distal coronary arteries. Extensive intercostal artery aneurysms were also noted. Several areas of abnormal myocardial perfusion were also noted. The patient improved after treatment with steroid pulses and cyclophosphamide. This case report is the first description of the appearance of lupus coronary vasculitis on cardiac computed tomography.

Aortic dissection as a rare complication of percutaneous coronary intervention

Aortic dissection is a rare but life-threatening complication that can occur during percutaneous coronary intervention procedures. We present a case of a 55-year-old woman who underwent a right coronary angioplasty that was complicated by a proximal dissection of the ascending aorta. Urgent surgical repair of the aorta was performed and the patient was discharged in stable clinical condition.

A case of delayed occlusive dissection of the right coronary artery during coronary intervention of the left anterior descending artery

Catheter-induced coronary artery dissection occurs rarely during selective coronary angiography but generally progresses to complete coronary occlusion. We present a case of delayed occlusive dissection of the right coronary artery during coronary intervention of the left anterior descending artery. Bailout stenting was employed to treat the giant hematoma quickly using a unique technique. The use of two guidewires created a high probability that the true lumen was selected, and aspiration of the hematoma with the microcatheter and indeflator effectively repaired a catheter-induced coronary artery dissection.

Diagnostic Accuracy of Dual-Source 64-Slice Multidetector Computed Tomography in Evaluation of Coronary Artery Bypass Grafts

Background

The aim of this study was to compare the diagnostic accuracy of 64-slice multidetector computed tomography (MDCT) with conventional coronary angiography to detect graft patency and stenosis.

Methods

In this retrospective analysis, we included a total of 284 subjects (210 men, 73.9%; mean ± SD age, 62.6 ± 9.9) and evaluated 684 bypass grafts using a dual-source 64-slice MDCT scanner The mean ± SD time interval between coronary artery bypass grafting operation and MDCT was 30.8 ± 6.2 months. The mean ± SD interval between MDCT angiography and conventional coronary angiography was 14.2 ± 3.6 days. Significant stenosis was defined as lesions causing 50% or greater luminal narrowing. All atherosclerotic lesion components were assessed on per-segment basis.

Results

All of the 684 grafts (420 venous and 264 arterial grafts) were evaluable and included in the analysis. For the detection of 50% or greater graft stenosis, the sensitivity, specificity, positive predictive value and negative predictive value of MDCT was 98.3%, 99.3%, 98.3%, and 99.3% for venous grafts and 100%, 99.5%, 98.0%, and 100% for arterial grafts. In detection of graft patency, the sensitivity, specificity, positive predictive value, and negative predictive value of MDCT was 99.6%, 97.2%, 99.0%, and 99.0% for venous grafts and 99.5%, 97.5%, 99.5%, and 97.5% for arterial grafts. Diagnostic accuracy for the detection of graft patency was 99% (416/420) and 99.2% (262/264) for venous and arterial grafts, respectively.

Conclusion

The diagnostic accuracy of dual-source 64-slice MDCT angiography for evaluating coronary artery bypass grafts patency and stenosis was high. Dual-source 64-slice MDCT can be used for the evaluation of patients after coronary artery bypass grafting.

Percutaneous coronary intervention through unintentional sheath placement in the inferior epigastric artery

A 64 year old female underwent percutaneous coronary intervention (PCI) with stent placement through the femoral approach. On femoral angiography after the PCI, the arterial sheath insertion site was found to be in the inferior epigastric artery and not in the common femoral artery. We used an Angioseal vascular closure device for management and there were no access site complications.

Diagnostic accuracy of 16- versus 64-slice multidetector computed tomography angiography in the evaluation of coronary artery bypass grafts: a comparative study

OBJECTIVES

Multidetector computed tomography (MDCT) angiography, which is used for native coronary vessels and bypass graft (CABG) imaging is a non-invasive test. Here, we aimed to compare the diagnostic accuracy of 16- and 64-slice MDCT for graft patency and stenosis.

METHODS

A total of 129 consecutive patients with CABG who underwent both MDCT (58 patients with 16-slice, 71 patients with 64-slice) and invasive angiography were included. Median time interval between the two procedures was 12 days (range 3-28 days). Bypass grafts were evaluated concerning patency and presence of stenosis ≥ 50%. Both 16- and 64-slice MDCT results were compared with invasive angiography.

RESULTS

Overall diagnostic accuracy for the detection of graft patency was 95% for 64-slice vs 92% for 16-slice MDCT. By analyzing the 173 grafts by 64-slice vs 153 grafts by 16-slice MDCT that could be evaluated, sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) of the MDCT for visualization of graft patency were 90, 98, 90 and 98% vs 87, 97, 94 and 93%, respectively. The accuracy of MDCT for the detection of significant graft stenosis was relatively low (sensitivity, specificity, PPV and NPV were 67, 98.6, 50 and 98.6% with 16-slice vs 80, 98.1, 72.7 and 98.7% with 64-slice).

CONCLUSIONS

This study showed that the 16-slice has a diagnostic accuracy comparable with the 64-slice system for graft patency and can still be used for this purpose if newer systems with improved performance are not available on-site. On the other hand, by the virtue of better image quality, the 64-slice MDCT demonstrates significant graft lesions with higher sensitivity.

Risks and complications of coronary angiography: a comprehensive review

Coronary angiography and heart catheterization are invaluable tests for the detection and quantification of coronary artery disease, identification of valvular and other structural abnormalities, and measurement of hemodynamic parameters. The risks and complications associated with these procedures relate to the patient’s concomitant conditions and to the skill and judgment of the operator. In this review, we examine in detail the major complications associated with invasive cardiac procedures and provide the reader with a comprehensive bibliography for advanced reading.

Perforation of the sinus of Valsalva by guiding catheter during the percutaneous coronary intervention via the right transradial approach: a very unusual complication

Iatrogenic dissection of the sinus of Valsalva or of the ascending aorta is a rare but potentially fatal event, during the percuteneous coronary intervention (PCI). We reported a case of perforation of the sinus of Valsalva by guiding catheter during PCI via the right transradial approach (TRA) successfully managed and sealed without any sequelae. The choice of guiding catheter into the right TRA should be done carefully and its manipulation should be performed with caution in the coronary artery and in the sinus of Valsalva.