2012 American College of Cardiology Foundation/Society for Cardiovascular Angiography and Interventions expert consensus document on cardiac catheterization laboratory standards update: A report of the American College of Cardiology Foundation Task Force on Expert Consensus documents developed in collaboration with the Society of Thoracic Surgeons and Society for Vascular Medicine

The functional assessment of patients with non-obstructive coronary artery disease: expert review from an international microcirculation working group

Symptomatic non-obstructive coronary artery disease (NOCAD) is an increasingly recognised entity that is associated with poor cardiovascular outcomes. Nearly half of those undergoing coronary angiography for appropriate indications, such as typical angina, or a positive stress test have no obstructive lesion. There are no guideline recommendations as to how to care properly for these patients. Physiologic assessment of the coronary arteries beyond two-dimensional angiography is not standardised, yet it can provide valuable information in patients presenting with typical angina in the setting of NOCAD. In this consensus document, we detail steps for the interventional cardiologist to evaluate the patient with symptomatic NOCAD in the cardiac catheterisation laboratory, first with the assessment of coronary flow reserve (CFR), and then with delineation of deficiencies in non-endothelium-dependent CFR (CFRne) versus endothelium-dependent CFR (CFRe) using provocative agents such as adenosine and acetylcholine, respectively, followed by the evaluation of smooth muscle function with nitroglycerine (NTG). Once the mechanism behind the anginal symptoms is established, one can identify the appropriate treatment strategies to address the physiologic deficiency that is present. Despite an established safety profile, a comprehensive assessment may be considered for selected patients which requires an understanding of the appropriate invasive evaluation by the practising interventional cardiologist when evaluating not only patients with obstructive CAD but also those with NOCAD.

Validation of a low-dose contrast 64-slice cardiac computed tomography angiography protocol for aortic valve annulus sizing

Cardiac computed tomography angiography (CCTA) is the gold standard for accurately sizing the aortic valve annulus prior to aortic valve replacement. A reduction of contrast volume administered for CCTA, without sacrificing image quality, is desirable. Signal-to-noise ratio represents final CCTA image quality. Consecutive patients referred to CCTA for aortic valve annulus sizing were retrospectively analyzed. Patients were grouped into a low-dose contrast (LDCT) group and traditional dose contrast (TDCT) group. In the LDCT group, contrast dose was <50% of the maximal allowable dose (3.7 × estimated glomerular filtration rate). Guided by a time-density curve, the contrast was administered in a two-stage infusion, and retrospectively gated images were acquired with a 64-multidetector computed tomography scanner. Out of 123 patients (age 80 ± 9 years; 46% female), 65 (52.9%) underwent LDCT and 58 (47.2%) underwent TDCT. Contrast volume was significantly lower in the LDCT group (LDCT 41.2 ± 9.8 vs TDCT 76.2 ± 14.2 mL; P < 0.001). The signal-to-noise ratio of the aortic root was 10.4 ± 4.1 for the LDCT group and 8.4 ± 3.3 for the TDCT group (P = 0.004). Aortic root dimensions could be measured in both LDCT and TDCT groups. In conclusion, LDCT with 64-slice CCTA can effectively size the aortic valve annulus to direct aortic valve replacement while offering reduced contrast exposure.

Operational and Institutional Recommendations and Requirements for TAVR: A Review of Expert Consensus and the Impact on Health Care Policy

When transcatheter aortic valve replacement (TAVR) was first approved for use in the United States in 2012, multiple leading surgical and cardiology societies were tasked with creating recommendations and requirements for operators and institutions starting and maintaining TAVR programs. Creation of this consensus document was challenging due to limited experience with this new technology, and a lack of robust centralized data that could be used to validate outcome measures and create benchmarks for self-assessment and improvement. Despite these limitations, this document provided government agencies a framework for regulation that ultimately determined requirements for Medicare payment for TAVR and therefore greatly determined how and where care was delivered for patients with aortic stenosis. After the proliferation of TAVR institutions throughout the US and with data from more than 100,000 cases in the STS/ACC Transcatheter Valve Therapies TM Registry, leaders of the same societies reconvened in 2018 to update their consensus document. The new recommendations include suggested personnel, facilities, training, and assessment of outcomes and competencies required to run a safe and efficient TAVR program. This article seeks to detail the changes from the original consensus document with a particular focus on issues relevant to cardiac anesthesiologists as well as important healthcare policy ramifications for patients and providers in the United States.

The current practice and care of paediatric patients post cardiac catheterisation

BACKGROUND

Literature is lacking to guide standardised care and assessment practices for paediatric patients post cardiac catheterisation. In response to this gap, we sought to describe the current state of practice in cardiology programmes performing paediatric cardiac catheterisations procedures in the United States of America.Materials and methodsA web-based survey was distributed to the Congenital Cardiovascular Interventional Study Consortium Listserv, with representation from 113 identified institutions. A 36-question survey, including fixed-choice and open-ended questions, was developed and piloted for reliability and validity before distribution. Data were summarised descriptively with count and frequency or median and range.

RESULTS

Of the 113 identified institutions, 52% (n=59) responded to the survey. Manual pressure is used to achieve haemostasis by 94.9% of the respondents. Pressure dressings are used by a majority of the facilities and the length of time for bed rest is variable, with the majority using 6 hours for arterial access and 4 hours for venous access. Predominantly, respondents use the time of haemostasis as the start time of bed rest while a third of respondents reported using the time the sheath was removed.

CONCLUSION

In this study, variation in a number of post catheterisation care and assessment practices for paediatric patients was noted across cardiology programmes. Information from this assessment identifies key opportunities to collaborate in developing standardised practices for the care and assessment of the paediatric patients post catheterisation.

Incidence and outcome of peri-procedural cardiogenic shock: results from the international Euro Heart Survey PCI registry

BACKGROUND

There is a large body of literature on acute myocardial infarction complicated by cardiogenic shock. However, very little is known about patients who are initially haemodynamically stable and develop cardiogenic shock during percutaneous coronary intervention.

METHODS

A total of 47,407 consecutive patients were prospectively enrolled in the PCI Registry of the Euro Heart Survey Programme. We analysed interventions with peri-procedural complications that were classified as 'shock induced by procedure' on the case report form. Clinical and procedural characteristics as well as hospital outcomes of haemodynamically stable patients who developed cardiogenic shock during percutaneous coronary intervention were evaluated. Patients with haemodynamic instability at presentation prior to intervention were excluded.

RESULTS

A total of 68 patients (0.2%) developed cardiogenic shock as a complication of percutaneous coronary intervention. The majority of cases comprised acute coronary syndrome (60.3%) with complex lesions (93.1%). Most patients had multi-vessel disease (82.1%) and an ejection fraction less than 40% (58.1%). In the multivariate analysis, left main disease (odds ratio (OR) 9.51), ST-segment elevation myocardial infarction (OR 5.31) and multi-vessel disease without left main involvement (OR 3.32) were the strongest independent predictors of peri-procedural cardiogenic shock. Among these patients procedural success was low (66.1%) and in-hospital mortality was very high (39.7%).

CONCLUSIONS

In this real-world registry the rate of haemodynamically stable patients who developed cardiogenic shock during percutaneous coronary intervention was very low. Patients at a priori high risk were more likely to be affected by this complication. The in-hospital mortality rate of these patients was very high.

Variability in radiation dose and image quality: A comparison across fluoroscopy-system vendors, generations of equipment and institutions

OBJECTIVES

To evaluate differences in radiation dose and image quality across institutions, fluoroscope vendors and generations of fluoroscopes for pediatric cardiac catheterization.

BACKGROUND

Increased recognition of the potentially harmful effects of ionizing radiation has spurred technological advances in fluoroscopes, as well as increased focus on optimizing fluoroscope performance. There is currently little understanding of variability in the dose-image quality relationship across institutions, fluoroscope vendor and/or generation of equipment.

METHODS

We evaluated latest generation fluoroscopes from Phillips, Siemens, GE, and Toshiba, and an older generation Phillips fluoroscope (release date 2003) at three different institutions. Radiation dose was measured using an anthropomorphic dose-assessment phantom with effective dose in mSv estimated from Monte Carlo simulations. Image quality phantom images were scored on a 12-point scale by three blinded reviewers.

RESULTS

Fluoroscope effective doses ranged from 0.04 to 0.14 mSv/1,000 pulses for fluoroscopy with associated composite image quality scores ranging from 8.0 ± 0.6 to 10.4 ± 1.3. For cineangiography, effective doses ranged from 0.17 to 0.57 mSv/1,000 frames with image quality scores ranging from 10.1 ± 0.3 to 11.1 ± 0.3. There was modest correlation between effective dose and image quality (r = 0.67, P = 0.006). The older generation fluoroscope delivered consistently higher doses than the newer generation systems (2.3- to 3.5-fold higher for fluoroscopy; 1.1- to 3.4-fold higher for cineangiography) without appreciable differences in image quality.

CONCLUSION

Technological advances have markedly improved fluoroscope performance. Comparing latest generation systems across vendors and institutions, we found variability in the dose-IQ relationship and speculate that this reflects both equipment and institutional optimization practices.

A propensity score matched valuation on feasibility of low frame rate fluoroscopy during primary percutaneous coronary intervention for patients with STEMI

The present study aimed to evaluate the feasibility of low frame rate fluoroscopy during primary percutaneous coronary intervention (PPCI) for patients with acute ST elevation myocardial infarction (STEMI). From January 2016 to December 2017, 165 consecutive patients with STEMI who underwent PPCI were retrospectively divided into two groups: the 7.5-frame group (fluoroscopy at 7.5 frames/s) and the 15-frame group (fluoroscopy at 15 frames/s), according to the frame rate of fluoroscopy used in their treatment. Reduction of radiation and safety of fluoroscopy at 7.5 frames/s were compared by a method of propensity score matching (PSM) with fluoroscopy at 15 frames/s. After PSM, there were 56 patients in each group. There were no differences in patients' baseline characteristics between two groups. The 7.5-frame protocol resulted in 48.9% reduction of DAP (9917 ± 5543 cGycm² vs. 14766 ± 7272 cGycm², P < 0.001) and 61.1% reduction of AK (1209 ± 562 mGy vs. 1948 ± 1105 mGy, P < 0.001) with comparable procedural time (38.1 ± 15.3 min vs. 38.8 ± 17.2 min, P = 0.830), fluoroscopy time (13.0 ± 7.2 min vs. 13.5 ± 8.1 min, P = 0.703) and contrast volume (122.3 ± 39.4 ml vs. 119.3 ± 49.4 ml, P = 0.725) to the 15-frame group. Meanwhile, this new protocol didn't increase the incidence of contrast-induced nephropathy (23.2% vs. 25.0%, OR = 0.907, 95% CI 0.381-2.157, P = 0.825) and peri-PPCI cumulative adverse events (30.4% vs. 28.6%, OR = 1.090, 95% CI 0.483-2.456, P = 0.836). In conclusion, low frame rate fluoroscopy at 7.5 frames/s is a safe and feasible strategy for reducing radiation during PPCI.

Meeting the evolving demands of neurointervention: Implementation and utilization of nurse practitioners

Growth in the neurointerventional field, as a result of the emergence of thrombectomy as the gold standard treatment for large vessel occlusions, has created complex challenges. In an effort to meet evolving demands and fill workflow gaps, nurse practitioners have taken on highly specialized roles. Neurointerventional care has rapidly evolved similarly to interventional cardiac care, in that nurse practitioners are successfully being incorporated as procedural assistants in catheterization laboratories. Similar utilization of nurse practitioners in interventional neuroradiology holds the capacity to decrease physician workload, mitigate stresses contributing to burn-out, and reallocate more physician time to procedures. Nurse practitioner practice faces procedural, clinical, legal and interpersonal barriers. Despite calls for expanded practice by the Institutes of Medicine, a paucity of nurse practitioner training opportunities exists. Fragmented privileging processes contribute to environments where nurse practitioners must navigate hurdles without established interventional neuroradiology-specific precedent. Increased nurse practitioner mentorship, fluoroscopy law standardization, physician support surrounding nurse practitioner autonomy, and role consistency is imperative for optimal nurse practitioner utilization. Nurse practitioners are uniquely equipped to bridge evolving gaps through the provision of safe, efficacious care, and generating revenue at lower costs. Discussion surrounding nurse practitioner use to bridge workflow gaps is an exciting opportunity for future practice development.

Cost analysis of combining congenital cardiac catheterization and electrophysiology procedures in an outpatient setting

BACKGROUND

Patients with congenital heart disease require multiple procedures over their lifetime. These procedures increase cost and time commitment. Previous studies in the field of medicine have shown that combining procedures is an effective method to reduce cost and time. There has been no such study to evaluate the cost and efficiency of combining pediatric cardiac procedures.

OBJECTIVE

The objective of this study was to compare the cost and time commitment of combined cardiac catheterization (cath) and electrophysiology (EP) outpatient procedures against separate cath and EP procedure.

METHODS

Outpatient combination procedures performed in the pediatric cardiac cath lab from 2013 to 2016 were matched to a control population of two or three similar single outpatient procedures from 2009 to 2016 for patients of similar age and cardiac anatomy. Procedure duration, recovery duration, length of stay, equipment charges, physician charges, all other hospital charges, and total admission charges were analyzed. The two groups were compared using an unpaired t-test.

RESULTS

A total of 92 subjects, 32 study subjects and 60 control subjects, were included in this study. Study group procedures had a significantly shorter recovery duration (P = 0.04) and length of stay (P = 0.01). Study group procedure duration trended shorter on average but statistically insignificant (P = 0.20). The total median savings for patients undergoing combined procedures in the study group was $13,181 (interquartile range $423.8-$26710).

CONCLUSIONS

Combining cath and EP outpatient procedures reduces the time commitment and provides some economic advantage.

Left ventricular end diastolic pressure and contrast-induced acute kidney injury in patients with acute coronary syndrome undergoing percutaneous coronary intervention

BACKGROUND

Left ventricular end-diastolic pressure (LVEDP) reflects ventricular performance and volume status. We sought to analyze the relationship between LVEDP and the incidence of contrast-induced acute kidney injury (AKI) in patients with acute coronary syndrome undergoing percutaneous coronary intervention (PCI).

METHODS

Between January 2006 and December 2008, a total of 254 patients presenting with an acute coronary syndrome had the LVEDP assessed prior to the intervention. Contrast-induced AKI was defined as an increase in serum creatinine ≥25% from baseline or an absolute increase of >0.5 mg/dL from baseline. Patients were divided into three groups according to baseline LVEDP (<12 mmHg, 12-20 mmHg and > 20 mmHg). Baseline clinical, angiographic and procedural characteristics, as well as serum creatinine and estimated glomerular filtration rate (eGFR) at baseline and at 24, 48 and 72 h were retrospectively collected.

RESULTS

Baseline clinical characteristics were similar in all three groups with the exception of lower left ventricular ejection fraction in patients with elevated LVEDP (p = 0.02). Among the 17 patients with an LVEDP < 12 mmHg, only one (5.9%) developed AKI; among the 82 patients with an LVEDP = 12-20 mmHg, 15 (18.3%) developed AKI; and among the 155 patients with an LVEDP > 20 mmHg, only 22 developed AKI (13.6%). There was no correlation between LVEDP and the change in GFR at 24 h and at 48 h. Further comparison between the group of patients that developed contrast induced AKI versus those that did not, showed a that there was a significantly lower baseline left ventricular ejection fraction (LVEF) among patients that developed contrast induced AKI compared to those that did not (41.4% vs. 48.3%, p = 0.045, respectively).

CONCLUSIONS

In patients with acute coronary syndrome undergoing PCI, baseline LVEDP was not associated with contrast-induced AKI. However patients with reduced ejection fraction seemed to be at a higher risk of developing AKI. More studies are needed to assess the relationship between LVEDP, LVEF and the risk of developing contrast induced AKI.

Utility of intracoronary imaging in the cardiac catheterization laboratory: comprehensive evaluation with intravascular ultrasound and optical coherence tomography

BACKGROUND

Intracoronary imaging is an important tool for guiding decision making in the cardiac catheterization laboratory.

SOURCES OF DATA

We have reviewed the latest available evidence in the field to highlight the various potential benefits of intravascular imaging.

AREAS OF AGREEMENT

Coronary angiography has been considered the gold standard test to appropriately diagnose and manage patients with coronary artery disease, but it has the inherent limitation of being a 2-dimensional x-ray lumenogram of a complex 3-dimensional vascular structure.

AREAS OF CONTROVERSY

There is well-established inter- and intra-observer variability in reporting coronary angiograms leading to potential variability in various management strategies. Intracoronary imaging improves the diagnostic accuracy while optimizing the results of an intervention. Utilization of intracoronary imaging modalities in routine practice however remains low worldwide. Increased costs, resources, time and expertise have been cited as explanations for low incorporation of these techniques.

GROWING POINTS

Intracoronary imaging supplements and enhances an operator's decision-making ability based on detailed and objective lesion assessment rather than a subjective visual estimation. The benefits of intravascular imaging are becoming more profound as the complexity of cases suitable for revascularization increases.

AREAS TIMELY FOR DEVELOPING RESEARCH

While the clinical benefits of intravascular ultrasound have been well validated, optical coherence tomography in comparison is a newer technology, with robust clinical trials assessing its clinical benefit are underway.

Utility of cardiac computed tomography scanning in the diagnosis and pre-operative evaluation of patients with infective endocarditis

Transesophageal echocardiography (TEE) is the gold standard imaging study used in the diagnosis of infective endocarditis (IE). Computed tomography angiography (CTA) has undergone rapid advancement as a cardiac imaging technique and has previously shown promise in small non-randomized studies for evaluation of IE. We hypothesized that cardiac CTA would perform similarly to TEE in the detection of endocarditic lesions and that there would be no difference in clinical outcomes whether the coronary arteries were evaluated by CTA or invasive coronary angiography (ICA). 255 adults who underwent surgery for IE at the Mayo Clinic Rochester between January 1, 2006 and June 1, 2014 were identified retrospectively. 251 patients underwent TEE and 34 patients underwent cardiac CTA. TEE had statistically higher detection of vegetations (95.6 vs. 70.0%, p < 0.0001) and leaflet perforations (81.3 vs. 42.9%, p = 0.02) as compared to cardiac CTA. For detection of abscess/pseudoaneurysm TEE had a similar sensitivity to cardiac CTA (90.5 vs. 78.4%, p = 0.21). There was no significant difference in peri-operative outcomes whether coronary arteries were evaluated by CTA or ICA. The greatest advantage of cardiac CT in the setting of IE is its ability to couple the detection of complex cardiac anatomic abnormalities with coronary artery delineation, serving two important components of the diagnostic evaluation, particularly among patients who will require surgical intervention due to IE complications. Cardiac CTA may be considered as an alternate coronary artery imaging modality in IE patients with low to intermediate risk of disease but meet guideline recommendations for coronary artery imaging.

Coronary microvascular dysfunction in patients with heart failure with preserved ejection fraction

There are multiple proposed mechanisms for the pathophysiology of heart failure (HF) with preserved ejection fraction (HFpEF). We hypothesized that coronary microvascular dysfunction is common in these patients. In a prospective, observational study, patients undergoing cardiac catheterization with HFpEF [left ventricular (LV) ejection fraction ≥ 50% and with clinical HF] were compared with similar patients without HFpEF. Patients with ≥50% stenosis were excluded, and coronary flow reserve (CFR) and the index of microvascular resistance (IMR) were measured after adenosine administration using a guidewire, with CFR ≤ 2 and IMR ≥ 23 being abnormal. Baseline characteristics and CFR and IMR were compared in 30 HFpEF patients and 14 control subjects. Compared with control subjects, HFpEF patients were older (65.4 ± 9.6 vs. 55.1 ± 3.1 yr, P < 0.01), had higher numbers of comorbidities (4.4 ± 1.5 vs. 2.6 ± 1.9, P = 0.002), had higher median B-type natriuretic peptide [161 (interquartile range: 75-511) pg/dl vs. 37 (interquartile range: 18.5-111) pg/dl, P < 0.01], and had higher LV end-diastolic pressure (17.8 ± 4.2 vs. 8.4 ± 4.2, P < 0.01). HFpEF patients had lower CFR (2.55 ± 1.60 vs. 3.84 ± 1.89, P = 0.024) and higher IMR (26.7 ± 10.3 vs. 19.7 ± 9.7 units, P = 0.037) than control subjects. Most (71.4%) control subjects had normal coronary physiology, whereas 36.7% of HFpEF patients had both abnormal CFR and IMR and another 36.7% had either abnormal CFR or IMR. In conclusion, this is the first study that has reported invasively determined CFR and IMR in HFpEF patients. We demonstrated the presence of four distinct coronary physiology groups in HFpEF patients. Investigation into the potential mechanisms for these findings is needed. NEW & NOTEWORTHY In this prospective observational study of patients with heart failure with preserved ejection fraction (HFpEF), we found that patients with HFpEF had more abnormalities of coronary flow and resistance than asymptomatic control patients, indicating that coronary microvascular dysfunction may play a role in the HFpEF disease process.

CKD-EPI versus Cockcroft-Gault formula for predicting contrast-induced nephropathy following percutaneous coronary intervention in patients without significant renal impairment

INTRODUCTION

Individuals with glomerular filtration rate (GFR) ≥60 ml/min/1.73 m² estimated by the Cockcroft-Gault formula (CG) who undergo percutaneous coronary intervention (PCI) frequently develop contrast-induced nephropathy (CIN). This study aimed to assess whether individuals with significant renal impairment assessed by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula, but not by CG, more often develop CIN following PCI than those without renal impairment by either formula.

METHODS

In this cross-sectional study analyzing patients with baseline CG GFR ≥60 ml/min/1.73 m² before PCI, subjects were divided into two groups according to CIN occurrence. Baseline CKD-EPI GFR was calculated for all patients.

RESULTS

We analyzed 140 patients. Baseline GFR was 87.5±21.3 and 77.1±15.0 ml/min/1.73 m² for CG and CKD-EPI, respectively. CIN occurred in 84.6% of individuals with baseline CKD-EPI GFR <60 ml/min/1.73 m² vs. 51.1% of those without. Males and those with higher body mass index were more likely to present baseline CKD-EPI GFR <60 ml/min/1.73 m² (p=0.021). Non-ionic contrast agent use and baseline CKD-EPI GFR ≥60 ml/min/1.73 m² were protective factors against CIN. Greater amounts of contrast agent and acute coronary syndrome were associated with higher CIN risk. In subjects with serum creatinine <1.0 mg/dl, GFR was more likely to be overestimated by CG, but not by CKD-EPI (sensitivity 100.0%; specificity 52.0%).

CONCLUSION

In patients undergoing PCI without renal dysfunction by CG, a finding of CKD-EPI GFR <60 ml/ min/1.73 m² was associated with a higher probability of CIN, especially among men and those with higher body mass index.

The Current Status of Percutaneous Coronary Intervention in Korea: Based on Year 2014 Cohort of Korean Percutaneous Coronary Intervention (K-PCI) Registry

BACKGROUND AND OBJECTIVES

Although several multicenter registries have evaluated percutaneous coronary intervention (PCI) procedures in Korea, those databases have been limited by non-standardized data collection and lack of uniform reporting methods. We aimed to collect and report data from a standardized database to analyze PCI procedures throughout the country.

MATERIALS AND METHODS

Both clinical and procedural data, as well as clinical outcomes data during hospital stay, were collected based on case report forms that used a standard set of 54 data elements. This report is based on 2014 Korean PCI registry cohort data.

RESULTS

A total of 92 hospitals offered data on 44967 PCI procedures. The median age was 66.0 interquartile range 57.0-74.0 years, and 70.3% were men. Thirty-eight percent of patients presented with acute myocardial infarction and one-third of all PCI procedures were performed in an urgent or emergency setting. Non-invasive stress tests were performed in 13.9% of cases, while coronary computed tomography angiography was used in 13.7% of cases prior to PCI. Radial artery access was used in 56.1% of all PCI procedures. Devices that used PCI included drug-eluting stent, plain old balloon angioplasty, drug-eluting balloon, and bare-metal stent (around 91%, 19%, 6%, and 1% of all procedures, respectively). The incidences of in-hospital death, non-fatal myocardial infarction, and stroke were 2.3%, 1.6%, and 0.2%, respectively.

CONCLUSION

These data may provide an overview of the current PCI practices and in-hospital outcomes in Korea and could be used as a foundation for developing treatment guidelines and nationwide clinical research.

OPERATOR DEPENDENCY OF THE RADIATION EXPOSURE IN CARDIAC INTERVENTIONS: FEASIBILITY OF ULTRA LOW DOSE LEVELS

INTRODUCTION

Mean radiation exposure in invasive cardiology varies greatly between different centres and interventionists. The International Commission on Radiological Protection and the EURATOM Council stipulate that, despite reference values, 'All medical exposure for radiodiagnostic purposes shall be kept as low as reasonably achievable' (ALARA). The purpose of this study is to establish the effects of the routine application of ALARA principles and to determine operator and procedure impact on radiation exposure in interventional cardiology.

MATERIALS AND METHODS

A total of 240 consecutive cardiac interventional procedures were analysed. Five operators performed the procedures, two of whom were working in accordance with ALARA principles (Group 1 operators) with the remaining three working in a standard manner (Group 2 operators). Radiation exposure levels of these two groups were compared.

RESULTS

Total fluoroscopy time and the number of radiographic runs were similar between groups. However, dose area product and cumulative dose were significantly lower in Group 1 when compared with Group 2. Radiation levels of Group 1 were far below even the reference levels in the literature, thus representing an ultra-low-dose radiation exposure in interventional cardiology.

CONCLUSION

By use of simple radiation reducing techniques, ultra-low-dose radiation exposure is feasible in interventional cardiology. Achievability of such levels depends greatly on operator awareness, desire, knowledge and experience of radiation protection.

Coronary artery calcification detection with invasive coronary angiography in comparison with unenhanced computed tomography

OBJECTIVE

The presence of extensive coronary artery calcifications (CAC) influences treatment decisions, particularly for revascularization. However, important CAC might be missed with invasive coronary angiography (ICA). Our aim was to determine the accuracy of ICA in the identification of CAC using computed tomography (CT) as reference standard.

PATIENTS AND METHODS

Overall, 349 consecutive patients who underwent both CT-based CAC-scoring and invasive coronary angiography within 60 days were retrospectively included. Two experienced operators classified CAC on ICA, without knowledge of CT-based CAC scoring, for each of the four main vessels as (0) absent, (1) mild, (2) moderate, or (3) dense calcifications. These scores were correlated with the CT-based Agatston CAC-scores, the noninvasive reference standard. The sensitivity, specificity, and accuracy of identified CAC using ICA were derived. Calcifications identified as moderate or dense on ICA or with a vessel-based Agatston score of more than 100 were considered important.

RESULTS

CT classified 671 (48%) of the 1396 vessels as having moderately or densely calcified vessels (Agatston score >100), whereas this was 137 (9.8%) using ICA (P<0.001). A significant correlation was found between the CT-based and ICA-based CAC-scores for all vessels (P<0.001). The sensitivity in detecting any CAC by means of ICA was 43% with a specificity of 92% and an accuracy of 55%. The sensitivity of important CAC identification by ICA was 19%, the specificity 99%, and the accuracy 61%.

CONCLUSION

The accuracy of ICA for the identification of calcifications is very low as only 19% of the relevant calcifications was identified. Preprocedural assessment of CAC with CT could be considered to improve the treatment approach.

Management of Patients on Non-Vitamin K Antagonist Oral Anticoagulants in the Acute Care and Periprocedural Setting: A Scientific Statement From the American Heart Association

Non-vitamin K oral anticoagulants (NOACs) are now widely used as alternatives to warfarin for stroke prevention in atrial fibrillation and management of venous thromboembolism. In clinical practice, there is still widespread uncertainty on how to manage patients on NOACs who bleed or who are at risk for bleeding. Clinical trial data related to NOAC reversal for bleeding and perioperative management are sparse, and recommendations are largely derived from expert opinion. Knowledge of time of last ingestion of the NOAC and renal function is critical to managing these patients given that laboratory measurement is challenging because of the lack of commercially available assays in the United States. Idarucizumab is available as an antidote to rapidly reverse the effects of dabigatran. At present, there is no specific antidote available in the United States for the oral factor Xa inhibitors. Prothrombin concentrate may be considered in life-threatening bleeding. Healthcare institutions should adopt a NOAC reversal and perioperative management protocol developed with multidisciplinary input.

Renal acoustic radiation force impulse elastography in the evaluation of coronary artery disease

Background Renal insufficiency may occur in patients with coronary artery disease (CAD). Acoustic radiation force impulse (ARFI) is a method for quantifying tissue elasticity, which could be used as an additional diagnostic test for renal insufficiency and provide an additional contribution to the determination of CAD. Purpose To evaluate ARFI elastography with shear wave velocity (SWV) measurements in the diagnosis of mild-to-moderate chronic kidney disease (CKD) in CAD patients, and to analyze the relationship between the severity of CAD assessed by the Gensini scoring system and kidney stiffness. Material and Methods The study included 76 CAD patients and 79 healthy volunteers. SWV was measured for each kidney in the both groups. The CAD group was divided into two subgroups based on Gensini score: mild CAD and severe CAD. SWV values of the CAD patients were compared to those of the healthy volunteers; values of subgroups were also compared with each other. Results The patient group had significantly lower renal mean SWV values than those of the healthy group (1.87 ± 0.58 vs. 2.34 ± 0.38, P < 0.01). The SWV value decreased as the eGFR level decreased. Mean SWV values for kidneys of the patients with severe CAD were lower than those of the mild CAD patients (1.64 ± 0.39 vs. 2.42 ± 0.60, P < 0.01). Conclusion renal mean SWV values of CAD patients decreased in proportion to the reduction in eGFR, and the SWV values decreased as the severity of CAD increased. ARFI elastography is a novel technique for diagnosing CKD and defining illness severity in CAD patients.

Relationship between hospital procedure volume and complications following congenital cardiac catheterization: A report from the IMproving Pediatric and Adult Congenital Treatment (IMPACT) registry

BACKGROUND

The association between institutional volume and outcomes has been demonstrated for cardiac catheterization among adults, but less is known about this relationship for patients with congenital heart disease (CHD) undergoing cardiac catheterization.

METHODS

Within the IMPACT registry, we identified all catheterizations between January 2011 and March 2015. Hierarchical logistic regression, adjusted for patient and procedural characteristics, was used to determine the association between annual catheterization lab volume and occurrence of a major adverse event (MAE).

RESULTS

Of 56,453 catheterizations at 77 hospitals, an MAE occurred in 1014 (1.8%) of cases. In unadjusted analysis, a MAE occurred in 2.8% (123/4460) of cases at low-volume hospitals (<150 procedures annually), as compared with 1.5% (198/12,787), 2.0% (431/21,391), and 1.5% (262/17,815) of cases at medium- (150-299 annual procedures), high- (300-499 annual procedures), and very-high-volume (≥500 procedures annually) hospitals, respectively, P<.001. After multivariable adjustment, this significant relationship between annual procedure volume and occurrence of an MAE persisted. Compared to low-volume programs, the odds of an MAE was 0.55 (95% CI 0.35-0.86, P=.008), 0.62 (95% CI 0.41-0.95, P=.03), and 0.52 (95% CI 0.31-0.90, P=.02) at medium-, high-, and very-high-volume programs, respectively.

CONCLUSIONS

Although the risk of MAE after cardiac catheterization in patients with CHD is low at all hospitals, it is higher among hospitals with fewer than 150 cases annually. These results support the notion that centers meeting this threshold volume for congenital cardiac catheterizations may achieve improved patient outcomes.

The need for maximal sterile barrier precaution in routine interventional coronary procedures; microbiology analysis

Background

Maximal sterile barrier precautions (MSBP) including head coverings and face masks are advocated for use in invasive procedures, including coronary interventions. The rationale for MSBP assumes it is an obligatory measure for infection prevention. However, in many coronary catheterization laboratories, head coverings/face masks are not used in daily practice. This study prospectively evaluated the potential hazards of not routinely using head coverings/face masks in routine coronary interventions.

Methods

This is a prospective study of ambulatory patients in hospital care. A total of 110 successive elective patients undergoing cardiac catheterizations were recruited. Patients were catheterized by several interventional cardiologists who employed only routine infection control precautions without head coverings or face masks. For each patient, we took blood cultures and cultures from the tips of the coronary catheters and from the sterile saline water flush bowl. Cultures were handled and analyzed at our certified hospital microbiology laboratory.

Results

In none of the cultures was a clinically significant bacterial growth isolated. No signs of infection were reported later by any of the study patients and there were no relevant subsequent admissions.

Conclusion

Operating in the catheterization lab without head coverings/face masks was not associated with any bacterial infection in multiple blood and equipment cultures. Accordingly, we believe that the use of head coverings/face masks should not be an obligatory requirement and may be used at the interventional cardiologist’s discretion.

Daily cardiac catheterization procedural volume and complications at an academic medical center

BACKGROUND

Over 1,000,000 cardiac catheterizations (CC) are performed annually in the United States. There is a small risk of complication that has persisted despite advances in technology. It is unknown whether daily CC procedural volume can influence this risk. In an effort to improve outcomes at our academic medical center, we investigated the relationship between daily CC volume and complication rates.

METHODS

We obtained data from both the National Cardiovascular Data Registry (NCDR) Cath-PCI and Lumedx© databases reviewing the records of patients undergoing scheduled, non-emergent CC at our facility between January 2005 to June 2013. Daily CC volume was analyzed as were complications including death, post-procedure MI, cardiogenic shock, heart failure, stroke, tamponade, bleeding, hematoma and acute kidney injury (AKI).

RESULTS

12,773 patients were identified who underwent 16,612 CCs on 2,118 days. The average age was 63 years (SD 12.4; range, 18-95). 61% were men. A total of 326 complications occurred in 243 patients on 233 separate days (2.0% CC complication rate). The average volume per day was 7.8 CCs. We found a low correlation between daily complications and CC volume (Spearman's rho =0.11; P<0.01) though complication rates were lowest on days with 6-11 procedures; higher rates were found on slower and busier days.

CONCLUSIONS

We observed a U-shaped association between CC volume and rates of CC complications. The lowest complication rates were found on days with 6-11 procedures a day. The highest complication rate was seen with >11 procedures a day.

Impact of imaging approach on radiation dose and associated cancer risk in children undergoing cardiac catheterization

OBJECTIVES

To quantify the impact of image optimization on absorbed radiation dose and associated risk in children undergoing cardiac catheterization.

BACKGROUND

Various imaging and fluoroscopy system technical parameters including camera magnification, source-to-image distance, collimation, antiscatter grids, beam quality, and pulse rates, all affect radiation dose but have not been well studied in younger children.

METHODS

We used anthropomorphic phantoms (ages: newborn and 5 years old) to measure surface radiation exposure from various imaging approaches and estimated absorbed organ doses and effective doses (ED) using Monte Carlo simulations. Models developed in the National Academies' Biological Effects of Ionizing Radiation VII report were used to compare an imaging protocol optimized for dose reduction versus suboptimal imaging (+20 cm source-to-image-distance, +1 magnification setting, no collimation) on lifetime attributable risk (LAR) of cancer.

RESULTS

For the newborn and 5-year-old phantoms, respectively ED changes were as follows: +157% and +232% for an increase from 6-inch to 10-inch camera magnification; +61% and +59% for a 20 cm increase in source-to-image-distance; -42% and -48% with addition of 1-inch periphery collimation; -31% and -46% with removal of the antiscatter grid. Compared with an optimized protocol, suboptimal imaging increased ED by 2.75-fold (newborn) and fourfold (5 years old). Estimated cancer LAR from 30-min of posteroanterior fluoroscopy using optimized versus suboptimal imaging, respectively was 0.42% versus 1.23% (newborn female), 0.20% versus 0.53% (newborn male), 0.47% versus 1.70% (5-year-old female) and 0.16% versus 0.69% (5-year-old male).

CONCLUSIONS

Radiation-related risks to children undergoing cardiac catheterization can be substantial but are markedly reduced with an optimized imaging approach. © 2016 Wiley Periodicals, Inc.

Comparison of Head Elevation Protocols Following Femoral Artery Sheath Removal After Coronary Angiography

OBJECTIVES

To compare 2 standard protocols for head elevation following removal of a femoral artery sheath after coronary angiography and their effects on bleeding complications and reported levels of back pain. One protocol involved flat supine bed rest; the other allowed progressive head elevation.

METHODS

A prospective comparative study of 80 adult patients undergoing coronary angiography via the femoral approach. The Numeric Rating Scale was used as the measure of reported pain.

RESULTS

No bleeding complications occurred in either group. Both groups had very low mean pain scores. Repeated-measures analysis demonstrated that the experience of pain differed significantly over time by location (F5,70 = 3.864, P = .004), with a notable decrease in pain scores more than 1 hour after sheath removal at the location that used the progressive head elevation protocol. Patients' satisfaction scores after discharge did not differ significantly between the 2 groups. Patients with a history of chronic back pain had consistently higher pain scores, but those pain scores did not differ significantly by location (or protocol).

CONCLUSIONS

It appears that using a progressive head-elevation protocol within the first 3 hours after diagnostic angiography is not associated with an increased risk of bleeding complications at the access site and warrants further exploration in the mitigation of back pain associated with prolonged supine bed rest.

Simplified Models of Non-Invasive Fractional Flow Reserve Based on CT Images

Invasive fractional flow reserve (FFR) is the gold standard to assess the functional coronary stenosis. The non-invasive assessment of diameter stenosis (DS) using coronary computed tomography angiography (CTA) has high false positive rate in contrast to FFR. Combining CTA with computational fluid dynamics (CFD), recent studies have shown promising predictions of FFRCT for superior assessment of lesion severity over CTA alone. The CFD models tend to be computationally expensive, however, and require several hours for completing analysis. Here, we introduce simplified models to predict noninvasive FFR at substantially less computational time. In this retrospective pilot study, 21 patients received coronary CTA. Subsequently a total of 32 vessels underwent invasive FFR measurement. For each vessel, FFR based on steady-state and analytical models (FFRSS and FFRAM, respectively) were calculated non-invasively based on CTA and compared with FFR. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value were 90.6% (87.5%), 80.0% (80.0%), 95.5% (90.9%), 88.9% (80.0%) and 91.3% (90.9%) respectively for FFRSS (and FFRAM) on a per-vessel basis, and were 75.0%, 50.0%, 86.4%, 62.5% and 79.2% respectively for DS. The area under the receiver operating characteristic curve (AUC) was 0.963, 0.954 and 0.741 for FFRSS, FFRAM and DS respectively, on a per-patient level. The results suggest that the CTA-derived FFRSS performed well in contrast to invasive FFR and they had better diagnostic performance than DS from CTA in the identification of functionally significant lesions. In contrast to FFRCT, FFRSS requires much less computational time.

Renal Safety of Iodinated Contrast Media Depending on Their Osmolarity - Current Outlooks

Iodinated contrast media (ICM) are commonly administered pharmaceutical agents. Most often they are used intravenously and intraarterially. Although iodinated contrast agents are relatively safe and widely used, adverse events occur and questions remain about their use, safety, and interactions. The most important adverse effects of contrast media include hypersensitivity reactions, thyroid dysfunction, and contrast-induced nephropathy. Radiologists must be aware of the risk factors for reactions to contrast media. Nonionic iodinated contrast agents can be divided into monomeric, low-osmolar, and dimeric, iso-osmolar classes. The osmotic characteristics of contrast media have been a significant focus in many investigations of contrast-induced nephropathy.

Management of Complications

Percutaneous coronary intervention (PCI) has matured rapidly to tackle increasingly complex coronary disease. Operators must be aware of the incidence of the basic risks involved with coronary angiography and PCI to appropriately inform patients and obtain procedural consent. Even before a wire enters a coronary artery, specific risks, including vascular access complications, renal injury, allergic reaction, and radiation injury, are constantly present. With initiation of PCI, new risks to the coronary circulation arise. A fundamental knowledge of the presentation of these complications and expert ability to emergently manage them are of the utmost importance to the successful completion of PCI.