American College of Cardiology/Society for Cardiac Angiography and Interventions Clinical Expert Consensus Document on cardiac catheterization laboratory standards. A report of the American College of Cardiology Task Force on Clinical Expert Consensus Documents

Assessing ischemic heart disease in patients with left bundle branch block--an emerging role for multislice computed tomography

Diagnosis of left bundle branch block (LBBB) with concomitant coronary artery disease (CAD) alters the prognosis and the therapeutic management. All common non-invasive stress tests have a limited performance to identify CAD in patients with LBBB. Thus invasive coronary angiography is often needed to confirm or defer obstructive CAD. We propose a new diagnostic algorithm in evaluation of symptomatic and asymptomatic patients with LBBB.

Cardiac MRI for detection of unrecognized myocardial infarction in patients with end-stage renal disease: comparison with ECG and scintigraphy

OBJECTIVE

The purposes of this study were to use the myocardial delayed enhancement technique of cardiac MRI to investigate the frequency of unrecognized myocardial infarction (MI) in patients with end-stage renal disease, to compare the findings with those of ECG and SPECT, and to examine factors that may influence the utility of these methods in the detection of MI.

SUBJECTS AND METHODS

We prospectively performed cardiac MRI, ECG, and SPECT to detect unrecognized MI in 72 patients with end-stage renal disease at high risk of coronary artery disease but without a clinical history of MI.

RESULTS

Fifty-six patients (78%) were men (mean age, 56.2 +/- 9.4 years) and 16 (22%) were women (mean age, 55.8 +/- 11.4). The mean left ventricular mass index was 103.4 +/- 27.3 g/m(2), and the mean ejection fraction was 60.6% +/- 15.5%. Myocardial delayed enhancement imaging depicted unrecognized MI in 18 patients (25%). ECG findings were abnormal in five patients (7%), and SPECT findings were abnormal in 19 patients (26%). ECG findings were false-negative in 14 cases and false-positive in one case. The accuracy, sensitivity, and specificity of ECG were 79.2%, 22.2%, and 98.1% (p = 0.002). SPECT findings were false-negative in six cases and false-positive in seven cases. The accuracy, sensitivity, and specificity of SPECT were 81.9%, 66.7%, and 87.0% (not significant). During a period of 4.9-77.9 months, 19 cardiac deaths were documented, but no statistical significance was found in survival analysis.

CONCLUSION

Cardiac MRI with myocardial delayed enhancement can depict unrecognized MI in patients with end-stage renal disease. ECG and SPECT had low sensitivity in detection of MI. Infarct size and left ventricular mass can influence the utility of these methods in the detection of MI.

The risks of inappropriateness in cardiac imaging

The immense clinical and scientific benefits of cardiovascular imaging are well-established, but are also true that 30 to 50% of all examinations are partially or totally inappropriate. Marketing messages, high patient demand and defensive medicine, lead to the vicious circle of the so-called Ulysses syndrome. Mr. Ulysses, a typical middle-aged “worried-well” asymptomatic subject with an A-type coronary personality, a heavy (opium) smoker, leading a stressful life, would be advised to have a cardiological check-up after 10 years of war. After a long journey across imaging laboratories, he will have stress echo, myocardial perfusion scintigraphy, PET-CT, 64-slice CT, and adenosine-MRI performed, with a cumulative cost of >100 times a simple exercise-electrocardiography test and a cumulative radiation dose of >4,000 chest x-rays, with a cancer risk of 1 in 100. Ulysses is tired of useless examinations, exorbitant costs. unaffordable even by the richest society, and unacceptable risks.

Sixty-four-slice multidetector computed tomography: an accurate imaging modality for the evaluation of coronary arteries in dilated cardiomyopathy of unknown etiology

BACKGROUND

The goal of this study was to assess the safety, feasibility, and diagnostic accuracy of 64-slice multidetector computed tomography (MDCT) for the evaluation of coronary arteries in dilated cardiomyopathy (DCM) of unknown etiology. Sixteen-slice MDCT is useful in patients affected by DCM. However, technical limitations, such as cardiac arrhythmias, an inability of patients to sustain a long breath-hold, and the need of a high dose of contrast agent may limit its accuracy and widespread use.

METHODS AND RESULTS

Invasive coronary angiography (ICA) and MDCT coronary angiography were performed on 132 consecutive patients (82 men; age 63+/-11 years) affected by DCM (ejection fraction, 34+/-10%) of unknown etiology. In 2 patients (1.5%), MDCT was not feasible because of atrial fibrillation. Of the remaining 130 patients, 88 exhibited normal and 42 exhibited diseased coronary arteries in both MDCT and ICA. All patients with coronary artery disease except for 1 were correctly classified by MDCT as 1-vessel (11 cases), 2-vessel (13 cases), and 3-vessel (18 cases) disease. In the segment-based analyses, the overall feasibility for MDCT was 98.5% (1902 of 1930 segments). Segment-based and patient-based analyses for the detection of luminal stenosis of >50% and >70% were performed. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MDCT for the detection of >50% stenosis were 98.1%, 99.9%, 98.7%, 99.8%, and 99.7%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MDCT for the detection of >70% stenosis were 99.5%, 98.6%, 94.1%, 99.9%, and 99.4%, respectively.

CONCLUSIONS

Excellent feasibility and diagnostic accuracy, combined with low invasiveness, make 64-slice MDCT an ideal imaging modality for the anatomic evaluation of coronary circulation in patients with DCM of unknown etiology.

Anesthesia in the cardiac catheterization laboratory and electrophysiology laboratory

Procedures and interventions in the cardiac catheterization laboratory (CCL) and electrophysiology laboratory (EPL) are more complex and involve acutely ill patients. Safely caring for this growing patient population in the CCL and EPL is now a concern for all anesthesiologists and cardiologists. Anesthesiologists are uniquely trained to care for this complex patient population, allowing the cardiologist to focus on completing the interventional procedure successfully.

The role of the out-of-operating room anesthesiologist in the care of the cardiac patient

Modern invasive cardiovascular procedures require patients to be both comfortable and cooperative. In addition, these procedures demand the complete attention of the attending cardiovascular specialist, and, to a large degree, the outcomes of these procedures depend on the amount of focus and concentration the cardiovascular specialist can give to performing the procedure itself. A team approach using the specialized skills of a cardiologist and an anesthesiologist frequently is required to optimize results. This article clearly delineates the procedures cardiologists perform that might involve anesthesiologists. Mutual knowledge, understanding, and respect are fundamental requirements for integration of cardiology and anesthesia services to optimize patient outcomes.

Cancer risk from professional exposure in staff working in cardiac catheterization laboratory: insights from the National Research Council's Biological Effects of Ionizing Radiation VII Report

BACKGROUND

Occupational doses from fluoroscopy-guided interventional procedures are the highest ones registered among medical staff using x-rays. The aim of the present study was to evaluate the order of magnitude of cancer risk caused by professional radiation exposure in modern invasive cardiology practice.

METHODS

From the dosimetric Tuscany Health Physics data bank of 2006, we selected dosimetric data of the 26 (7 women, 19 men; age 46 +/- 9 years) workers of the cardiovascular catheterization laboratory with effective dose >2 mSv. Effective dose (E) was expressed in milliSievert, calculated from personal dose equivalent registered by the thermoluminescent dosimeter, at waist or chest, under the apron, according to the recommendations of National Council of Radiation Protection. Lifetime attributable risk of cancer was estimated using the approach of Biological Effects of Ionizing Radiation 2006 report VII.

RESULTS

Cardiac catheterization laboratory staff represented 67% of the 6 workers with yearly exposure >6 mSv. Of the 26 workers with 2006 exposure >2 mSv, 15 of them had complete records of at least 10 (up to 25) consecutive years. For these 15 subjects having a more complete lifetime dosimetric history, the median individual effective dose was 46 mSv (interquartile range = 24-64). The median risk of (fatal and nonfatal) cancer (Biological Effects of Ionizing Radiation 2006) was 1 in 192 (interquartile range = 1 in 137-1 in 370).

CONCLUSIONS

Cumulative professional radiological exposure is associated with a non-negligible Lifetime attributable risk of cancer for the most exposed contemporary cardiac catheterization laboratory staff.

Diagnostic performance of 64-multidetector row coronary computed tomographic angiography for evaluation of coronary artery stenosis in individuals without known coronary artery disease: results from the prospective multicenter ACCURACY (Assessment by Coronary Computed Tomographic Angiography of Individuals Undergoing Invasive Coronary Angiography) trial

OBJECTIVES

The purpose of this study was to evaluate the diagnostic accuracy of electrocardiographically gated 64-multidetector row coronary computed tomographic angiography (CCTA) in individuals without known coronary artery disease (CAD).

BACKGROUND

CCTA is a promising method for detection and exclusion of obstructive coronary artery stenosis. To date, no prospective multicenter trial has evaluated the diagnostic accuracy of 64-multidetector row CCTA in populations with intermediate prevalence of CAD.

METHODS

We prospectively evaluated subjects with chest pain at 16 sites who were clinically referred for invasive coronary angiography (ICA). CCTAs were scored by consensus of 3 independent blinded readers. The ICAs were evaluated for coronary stenosis based on quantitative coronary angiography (QCA). No subjects were excluded for baseline coronary artery calcium score or body mass index.

RESULTS

A total of 230 subjects underwent both CCTA and ICA (59.1% male; mean age: 57 +/- 10 years). On a patient-based model, the sensitivity, specificity, and positive and negative predictive values to detect > or =50% or > or =70% stenosis were 95%, 83%, 64%, and 99%, respectively, and 94%, 83%, 48%, 99%, respectively. No differences in sensitivity and specificity were noted for nonobese compared with obese subjects or for heart rates < or =65 beats/min compared with >65 beats/min, whereas calcium scores >400 reduced specificity significantly.

CONCLUSIONS

In this prospective multicenter trial of chest pain patients without known CAD, 64-multidetector row CCTA possesses high diagnostic accuracy for detection of obstructive coronary stenosis at both thresholds of 50% and 70% stenosis. Importantly, the 99% negative predictive value at the patient and vessel level establishes CCTA as an effective noninvasive alternative to ICA to rule out obstructive coronary artery stenosis. (A Study of Computed Tomography [CT] for Evaluation of Coronary Artery Blockages in Typical or Atypical Chest Pain; NCT00348569).

Dual-source CT for visualization of the coronary arteries in heart transplant patients with high heart rates

OBJECTIVE

The purpose of this study was to evaluate the quality of dual-source CT images of the coronary arteries in heart transplant recipients with high heart rates.

SUBJECTS AND METHODS

Contrast-enhanced dual-source CT coronary angiography was performed on 23 heart transplant recipients (20 men, three women; mean age, 61.1 +/- 12.8 years). Data sets were reconstructed in 5% steps from 30% to 80% of the R-R interval. Two blinded independent readers using a 5-point scale (0, not evaluative; 4, excellent quality) assessed the quality of images of coronary segments.

RESULTS

The mean heart rate during scanning was 89.2 +/- 10.4 beats/min. Interobserver agreement on the quality of images of the whole coronary tree was a kappa value of 0.78 and for selection of the optimal reconstruction interval was a kappa value of 0.82. The optimal reconstruction interval was systole in 17 (74%) of the 23 of heart transplant recipients. At the best reconstruction interval, diagnostic image quality (score >or= 2) was obtained in 92.1% (303 of 329) of the coronary artery segments. The mean image quality score for the whole coronary tree was 3.1 +/- 1.01. No significant correlation between mean heart rate (rho = 0.31) or heart rate variability (rho = 0.23) and overall image quality score was observed (p = not significant).

CONCLUSION

Dual-source CT acquisition yields coronary angiograms of diagnostic quality in heart transplant recipients. Mean heart rate and heart rate variability during scanning do not have a negative effect on the overall quality of images of the coronary arteries.

Body weight limitations of United States cardiac catheterization laboratories including restricted access for the morbidly obese

A telephone survey was performed to determine the current weight limits of cardiovascular catheterization laboratories (n = 94) in the United States. The minimum, mean, and maximum weight limits of the catheterization laboratories in this survey were 160, 198.9, and 250 kg (350, 437.5, and 550 lb), respectively. Twenty-two percent of respondents (n = 21) referred to other institutions when asked what they did when patients were too heavy, and 70% of respondents (n = 66) could not provide an answer. In this population, 5.2 +/- 3.4 patients/hospital/year were rejected for being over the weight limit. In conclusion, these results provide useful information for the future management of this growing population.

Rationale, design and methodology for a Prospective Randomized Study of graft patency in Off-pump and On-pump MultI-vessel coronary artery bypasS Surgery (PROMISS) using multidetector computed tomography

Background

Off-pump coronary artery bypass grafting has been accused of possibly compromising graft patency. Sixteen slice computed tomography has shown good diagnostic accuracy in the assessment of coronary bypass graft patency when compared with conventional coronary artery angiography and is less invasive. The study hypothesis is that coronary artery bypass grafting (CABG) performed without cardiopulmonary bypass (Off-Pump) has equivalent early graft patency as if performed with cardiopulmonary bypass (On-Pump) and may have reduced complication rate.

Methods/Design

The Prospective Randomized Comparison of Off-Pump and On-Pump MultI-vessel Coronary Artery BypasS Surgery (PROMISS) is a controlled, single blinded, single centre clinical trial, comparing early graft patency using 16-slice computed tomography in patients with multi-vessel coronary artery disease operated either without or with extracorporeal circulation. Inclusion criteria are multivessel disease with an indication for first time, isolated, non emergent coronary artery bypass grafting with a minimum of three distal anastomoses. Secondary end points are peri-operative mortality, combined morbidity, length of stay, neuro-cognitive testing at 6 weeks and adverse events, stress test and quality of life at 6 months and one year. The sample size of one hundred and fifty patients was calculated in order to enable the detection of a 5% difference in graft patency, with 80% power, considering a minimum of 3 distal anastomoses per patient. Enrolment started in April 2005 and ended July 2007 with study closure in July 2008.

Conclusion

The PROMISS trial aims to shed new light on the effect of Off-Pump as compared to On-Pump coronary artery bypass surgery on graft patency, assessed by multidetector computed tomography, in unselected patients with multivessel coronary artery disease.

Trial Registration

Current Controlled Trials ISRCTN58800729

Characterization of coronary atherosclerosis by dual-source computed tomography and HU-based color mapping: a pilot study

To assess HU-based color mapping for characterization of coronary plaque, using intravascular ultrasound virtual histology (IVUS-VH) as a standard of reference. Dual-source computed tomography and IVUS-VH were prospectively performed in 13 patients. In five lesions, HU thresholds of the color-coding software were calibrated to IVUS-VH. In a 15-lesion verification cohort, volumes of vessel, lumen and plaque or percentages of lipid, fibrous and calcified components were obtained through use of pre-set HU cut-offs as well as through purely visual adjustment of color maps. Calibrated HU ranges for fatty or fibrous plaque, lumen and calcification were -10-69, 70-158, 159-436 and 437+. Using these cut-offs, HU-based analysis achieved good agreement of plaque volume with IVUS (47.0 vs. 51.0 mm(3)). Visual segmentation led to significant overestimation of atheroma (61.6 vs. 51.0 mm(3); P = 0.04) Correlation coefficients for volumes of vessel, lumen and plaque were 0.92, 0.87 and 0.83 with HU-based analysis or 0.92, 0.85 and 0.71 with visual evaluation. With both methods, correlation of percentage plaque composition was poor or insignificant. HU-based plaque analysis showed good reproducibility with intra-class correlation coefficients being 0.90 for plaque volume and 0.81, 0.94 or 0.98 for percentages of fatty, fibrous or calcified components. With use of optimized HU thresholds, color mapping allows for accurate and reproducible quantification of coronary plaque.

Usefulness of clinical, echocardiographic, and procedural characteristics to predict outcome after percutaneous transluminal septal myocardial ablation

This study was conducted to assess outcomes after percutaneous transluminal septal myocardial ablation (PTSMA) treatment in 131 patients (mean age 56+/-16 years) with obstructive hypertrophic cardiomyopathy. In-hospital and follow-up complications as well as late PTSMA failure (defined as unsatisfactory clinical outcome and a significant residual outflow tract gradient, necessitating reintervention) were noted. Baseline clinical, echocardiographic, and PTSMA characteristics were examined as determinants of outcomes. Also, the effect of ethanol volume and the role of a learning curve were investigated. PTSMA was successful in 90% of the patients. In-hospital and follow-up cardiac events were noted in 20 patients, including cardiac death (in-hospital n=4, follow-up n=1), acute myocardial infarction due to ethanol leakage (n=1), coronary dissection (n=2), nonfatal cardiac tamponade (n=1), and permanent pacemaker (n=6) or cardiac defibrillator (in-hospital n=4, follow-up n=1) implantation. Late PTSMA failure was noted in 12 patients. All baseline characteristics were comparable between successful and failed PTSMA. Ethanol volume was related to peak creatinine kinase value (p<0.0001) but not to late PTSMA failure or greater need for pacemaker implantation. Late PTSMA failure occurred more frequently in PTSMA procedures performed in the early, less experienced time period (p<0.001). In conclusion, this study confirms that PTSMA, although effective, has a relatively high complication rate. Late PTSMA failure could not be predicted by baseline characteristics but could partially be explained by a learning-curve effect. This finding implies that PTSMA procedures should be restricted to experienced centers.

Noninvasive coronary angiography using 64-slice spiral computed tomography in an unselected patient collective: Effect of heart rate, heart rate variability and coronary calcifications on image quality and diagnostic accuracy

OBJECTIVE

The aim of this study was to assess the impact of heart rate, heart rate variability and calcification on image quality and diagnostic accuracy in an unselected patient collective.

SUBJECTS AND METHODS

One hundred and two consecutive patients with known or suspected coronary artery disease underwent both 64-MSCT and invasive coronary angiography. Image quality (IQ) was assessed by independent observers using a 4-point scale from excellent (1) to non-diagnostic (4). Accuracy of MSCT regarding detection or exclusion of significant stenosis (>50%) was evaluated on a per segment basis in a modified AHA 13-segment model. Effects of heart rate, heart rate variability, calcification and body mass index (BMI) on IQ and accuracy were evaluated by multivariate regression. IQ and accuracy were further analysed in subgroups of significant predictor variables and simple regression performed to calculate thresholds for adequate IQ.

RESULTS

Mean heart rate was 68.2+/-13.3 bpm, mean heart rate variability 11.5+/-16.0 beats per CT-examination (bpct) and median Agatston score 226.5. Average IQ score was 2+/-0.6 whilst diagnostic quality was obtained in 89% of segments. Overall sensitivity, specificity, PPV or NPV was 91.2%, 99.2%, 95.3% or 98.3%. According to multivariate regression, overall IQ was significantly related to heart rate and calcification (P=0.0038; P<0.0001). The effect of heart rate variability was limited to IQ of RCA segments (P=0.018); BMI was not related to IQ (P=0.52). Calcification was the only predictor variable with significant effect on the number of non-diagnostic segments (P<0.0001). In a multivariate regression, calcification was also the single factor with impact on diagnostic accuracy (P=0.0049).

CONCLUSION

Whilst heart rate, heart rate variability and calcification all show an inverse correlation to IQ, severe calcium burden remains the single factor with translation of such effect into decrease of diagnostic accuracy.

Dual-source CT: effect of heart rate, heart rate variability, and calcification on image quality and diagnostic accuracy

PURPOSE

To prospectively evaluate the effect of heart rate, heart rate variability, and calcification on dual-source computed tomography (CT) image quality and to prospectively assess diagnostic accuracy of dual-source CT for coronary artery stenosis, by using invasive coronary angiography as the reference standard.

MATERIALS AND METHODS

This study had local Ethics Committee approval; all patients gave informed consent. Patients who underwent bypass surgery were excluded; patients with coronary artery stent-grafts were included. One hundred patients (20 women, 80 men; mean age, 62 years +/- 10 [standard deviation]) known to have or suspected of having coronary artery disease underwent dual-source CT and invasive coronary angiography. Image quality was assessed. Accuracy of dual-source CT in depiction or exclusion of significant stenosis (>or=50%) was evaluated on a per-segment and per-patient basis. Effects of heart rate, heart rate variability, and calcification on image quality and accuracy were analyzed by using multivariate regression and were analyzed between subgroups of predictor variables. Simple regression was performed to calculate thresholds for adequate image quality.

RESULTS

Mean heart rate was 64.9 beats per minute +/- 13.2, mean variability was 23.6 beats per CT examination +/- 36.2, and mean Agatston score was 786.5 +/- 965.9. Diagnostic image quality was obtained in 90.2% of segments. Sensitivity, specificity, and positive and negative predictive values for the presence of significant stenosis were, respectively, 91.1%, 92.0%, 75.4%, and 97.5% by segment and 100%, 81.5%, 93.6%, and 100% by patient. Image quality was significantly related to heart rate variability (P = .015) and calcification (P < .001); the number of nondiagnostic segments was significantly affected by calcification only. Calcification was the single factor with significant impact on diagnostic accuracy (P = .001).

CONCLUSION

While dual-source CT resulted in heart-rate independent image quality, image quality remained prone to heart rate variability and calcification.

Stress echocardiography, stress single-photon-emission computed tomography and electron beam computed tomography for the assessment of coronary artery disease: a meta-analysis of diagnostic performance

BACKGROUND

Many studies have been published on the diagnostic performance of noninvasive tests for the assessment of coronary artery disease. The objective of the present study was to compare the published literature on the diagnostic performance of stress echocardiography, stress single-photon-emission computed tomography (SPECT), and electron beam computed tomography (EBCT).

METHODS

Meta-analytic studies on the diagnostic performance of imaging tests for coronary artery disease were searched in the Cochrane Library, PubMed, and bibliographies of selected articles. Sensitivities, specificities, and diagnostic odds ratios of the source studies were calculated per modality. Taking into account differences between studies, a random effects summary receiver operating characteristic analysis was performed.

RESULTS

We analyzed the data of 351 patient series, which were reported in 11 meta-analyses. The sensitivity of EBCT was significantly higher than that of stress SPECT, which had a significantly higher sensitivity than stress echocardiography (respectively, 93.1% [95% confidence interval, 90.7-95.6], 88.1 [95% confidence interval, 86.6-89.6], and 79.1% [95% confidence interval, 77.6-80.5]). The specificity of stress echocardiography was significantly higher than that of stress SPECT, which had a significantly higher specificity than EBCT (respectively, 87.1% [95% confidence interval, 85.7-88.5], 73.0% [95% confidence interval, 69.1-76.9], and 54.5% [95% confidence interval, 45.3-63.8]). The diagnostic odds ratios did not differ significantly between the 3 modalities, which resulted in one underlying summary receiver operating characteristic curve.

CONCLUSIONS

This study suggests that there are no significant differences in the overall diagnostic performance between stress echocardiography, stress SPECT, and EBCT for the diagnosis of coronary artery disease. However, differences exist in sensitivity and specificity estimates, which may make each modality useful in different settings.

Predicting breast attenuation in patients undergoing myocardial perfusion scintigraphy: a digital x-ray study

Attenuation artifacts are the most common sources of error in myocardial single-photon emission computed tomography (SPECT) imaging. Breast artifacts are the most frequent causes of false positive planar images in female subjects. The purpose of this study was to predict breast adverse attenuation by measuring breast tissue thickness with digital x-ray. Sixty-five consecutive female patients with angina pectoris, who were referred to myocardial perfusion scintigraphy were enrolled in this study. Eighteen patients with normal perfusion imaging and normal coronary angiography composed the first group, whereas the second group consisted of 28 patients with a positive exercise electrocardiogram with anterior ischemia on myocardial perfusion imaging and greater than 50% left anterior descending artery stenosis on angiography. Nineteen patients in the third group had normal exercise electrocardiograms and normal coronary angiographies, but anterior ischemia on perfusion imaging. Digital x-ray records were obtained for measuring breast tissue thickness and Hounsfield density. The rate of breast adverse attenuation was 40% (19/47) in patients with anterior ischemia. The sensitivity and specificity of the prediction of breast adverse attenuation (lateral density less than 550 Hounsfield) were 79% and 11%, respectively. When breast attenuation for a breast thickness greater than 6 cm measured in the left anterior oblique view was predicted, the sensitivity and specificity were 79% and 93%, respectively. In conclusion, breast thickness greater than 6 cm measured from the left anterior oblique view with digital x-ray can predict breast adverse attenuation in female patients, and thereby may decrease the number of unnecessary invasive diagnostic procedures to be performed.

Offsite anesthesiology in the cardiac catheterization lab

PURPOSE OF REVIEW

The cardiac catheterization lab has concerns for both patient care and for safety. As the cardiac catheterization lab continues to evolve, the demand for anesthesia services will certainly increase. The role of the anesthesiologist in the cardiac catheterization lab must be defined in this changing environment.

RECENT FINDINGS

Procedures in the cardiac catheterization lab are more complex, take longer, and involve higher acuity patients. Many of these cases require general anesthesia rather than sedation, and require management of unstable hemodynamics. Knowledge of echocardiography and fluoroscopy is beneficial. Anesthesiologists should be active in developing sedation and practice management guidelines. Radiation exposure and safety is an important concern.

SUMMARY

The anesthesiologist is becoming an integral part of the cardiac catheterization lab team, and an important element in maintaining a high level of patient care with minimal complications in the evolving modern day cardiac catheterization lab.

Detection of significant coronary artery stenosis with 64-section MDCT angiography

PURPOSE

To prospectively evaluate the diagnostic performance of 64-section multidetector computed tomography (MDCT) to detect significant coronary artery stenosis using conventional coronary angiography (CCA) as the reference standard.

MATERIALS AND METHODS

Institutional Review Board approval and informed consent were obtained. In this prospective study, 80 patients (61 male, 19 female, mean age 56) were examined. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated. McNemar test was used to search for the significant difference between 64-section MDCT angiography and CCA to detect stenosis. Also, kappa index (kappa) for the agreement between MDCT angiography and CCA was calculated.

RESULTS

The sensitivity, specificity, positive (PPV) and negative predictive values (NPV) for detecting significant stenosis were 96%, 98%, 91%, 99%, respectively. The sensitivity, specificity, PPV and NPV for classification of patients with or without CAD were 100% for all. McNemar test demonstrated no significant difference between 64-section MDCT angiography and CCA. Also, kappa index (kappa) indicated excellent agreement.

CONCLUSION

Sixty-four section MDCT angiography is an effective diagnostic tool for the detection of significant coronary artery stenosis. Especially, the potential to differentiate patients with and without CAD may provide MDCT an important role in the prevention of unnecessary invasive diagnostic procedures.

Diagnostic accuracy of multidetector computed tomography coronary angiography in patients with dilated cardiomyopathy

OBJECTIVES

The purpose of this work was to assess the safety, feasibility, and diagnostic accuracy of multidetector computed tomography (MDCT) in dilated cardiomyopathy (DCM) of unknown etiology.

BACKGROUND

Multidetector computed tomography is an appropriate noninvasive tool for coronary artery disease (CAD) detection, particularly in patients with low probability of the disease, such as patients with DCM of unknown origin.

METHODS

We studied 61 unknown origin DCM patients (ejection fraction: 33.9 +/- 8.6%, group 1) and 139 patients with normal cardiac function with indications for coronary angiography (group 2, control population). All underwent coronary MDCT and angiography. Multidetector computed tomography images were acquired by light speed 16-slice computed tomography. The degree of stenosis was estimated in 15 coronary artery segments according to the American Heart Association model.

RESULTS

In group 1, no MDCT-related complications were found, while 10 complications were associated with conventional angiography (p = 0.001). Overall feasibility of coronary artery visualization was 97.2% (863 of 888 segments). The most frequent cause of artifacts was interference from a hypertrophic cardiac venous system (10 artifacts, 40%). In group 2, overall feasibility was 96.1% (p = NS vs. group 1). In group 1, all cases with normal (44 cases) or pathological (17 cases) coronary arteries by conventional coronary angiography were correctly detected by MDCT, with, in 1 case, disparity of stenosis severity. In group 1, sensitivity, specificity, and positive and negative predictive values of MDCT for the identification of >50% stenosis were 99%, 96.2%, 81.2%, and 99.8%, respectively. In group 2, sensitivity and negative predictive values were lower than in group 1 (86.1% vs. 99% and 96.4% vs. 99.8%, respectively); specificity (96.4%) and positive predictive value (86.1%) were not significantly different versus group 1.

CONCLUSIONS

Multidetector computed tomography is feasible, safe, and accurate for identification of idiopathic versus ischemic DCM, and may represent an alternative to coronary angiography.

Bypass Graft and Native Postanastomotic Coronary Artery Patency: Assessment With Computed Tomography

BACKGROUND

Multidetector computed tomography has been shown to be useful in the evaluation of coronary artery bypass grafts in previous studies. We studied the accuracy of multidetector computed tomography in the detection of patency and significant stenosis of both grafts and native postanastomotic coronary arteries.

METHODS

Ninety-six patients with 216 grafts (98 left mammary artery, 8 right mammary artery, 8 radial artery, and 102 venous grafts) were investigated by 16-slice computed tomography. Native postanastomotic coronary arteries were also evaluated. Patients unable to maintain a breath hold of 40 s were excluded. Computed tomography data were compared with the results of conventional angiography.

RESULTS

On a segment-based model, the overall feasibility of computed tomography was 98.1% (212 of 216 grafts) for bypass grafts and 93.1% (201 of 216 segments) for postanastomotic coronary arteries. The leading cause of unfeasibility for postanastomotic coronary arteries was the small diameter of the examined vessel (<1.5 mm). Computed tomography correctly diagnosed all the 25 occluded grafts. Of the 33 significant stenoses of grafts, computed tomography correctly diagnosed 31. Sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 98.5%, 96.5%, and 100%, respectively, for bypass graft; and 100%, 97.7%, 85%, and 100%, respectively, for coronary arteries. On a patient-based model, the feasibility, sensitivity, specificity, positive predictive value, and negative predictive value were 89.4% (86 of 96 patients), 100%, 93%, 86.4%, and 100%, respectively.

CONCLUSIONS

Multidetector computed tomography allows a very accurate assessment of arterial and venous conduits and of postanastomotic native coronary arteries in patients with previous bypass graft. Despite high feasibility (93.1%), limitations of the method were breath-hold duration (35 to 40 s) and postanastomotic assessment of small vessels (which, however, precluded the analysis in only 4.6% of cases).

Sixty-four–slice multidetector computed tomography: the future of ED cardiac care

Multidetector computed tomography (MDCT) imaging, a technological advance over traditional CT, is a promising possible alternative to cardiac catheterization for evaluating patients with chest pain in the emergency department (ED). In comparison with traditional CT, MDCT offers increased spatial and temporal resolution that allows reliable visualization of the coronary arteries. In addition, a "triple scan," which includes evaluation for pulmonary embolism and thoracic aortic dissection, can be incorporated into a single study. This test will enable emergency physicians to rapidly evaluate patients for life-threatening illnesses and may allow safer and earlier discharges of many patients with chest pain in comparison with a traditional rule-out protocol. In this article, we will highlight the technological advances of MDCT imaging, review the literature on coronary angiography via MDCT, and discuss the future of this technology as it relates to the ED.

Feasibility and diagnostic accuracy of 16-slice multidetector computed tomography coronary angiography in 500 consecutive patients: critical role of heart rate

PURPOSE

To evaluate the feasibility and diagnostic accuracy of multidetector computed tomography coronary (MDCT) angiography applied to an unselected heart-disease population, to identify all causes of unfeasibility of exams, the distribution of artifacts in every coronary segment and their influence on diagnostic accuracy of examination.

MATERIALS AND METHODS

We evaluated 500 patients with different indications for invasive coronary angiography. All underwent coronary MDCT and ICA. 215 patients were pre-treated with metoprolol intravenously. In the whole population we studied native coronary arteries and in 141 cases the patency of coronary artery bypass grafts (CABG). The quality of MDCT images was graded as good, sufficient and insufficient.

RESULTS

We were able to evaluate the patency of all grafts, with the exception of 4 cases. Diagnostic accuracy of CABG evaluation was very high (sensitivity 100%, specificity 98.4%). In native coronary arteries the overall feasibility was 97.9%. The middle left circumflex artery, right coronary artery and posterior descending artery were the segments most often poorly visualized. The first cause of artifacts was misalignment related to high heart rate, followed by premature heart beats and calcified plaque. The population was separated into 3 groups: group 1: heart rate <55 bpm, group 2: 55-65 bpm, group 3: >65 bpm. In group 1, misalignment was significantly lower than in groups 2 and 3. On a segment-based analysis, overall feasibility was therefore significantly higher in group 1 vs group 2 and vs group 3. Images of good quality were significantly higher in group 1 (95.4%) than in group 2 (87%) and group 3 (71.8%). The higher image quality in group 1 impacts on the overall diagnostic accuracy of the exam. Indeed overall sensitivity is significantly higher in group 1 (89.5%) than in group 2 (86%) and group 3 (82.8%) and overall specificity is significantly higher in group 1 than in group 3.

CONCLUSIONS

Multidetector computed tomography has a high feasibility and diagnostic accuracy for the evaluation of coronary artery disease in an unselected population. Good patient preparation (optimized beta-blocker therapy, correct breathing instructions) is essential for evaluating native coronary arteries while preparation with a beta-blocker is less relevant in bypass graft patients.

Late gadolinium-enhanced cardiovascular magnetic resonance identifies patients with standardized definition of ischemic cardiomyopathy: A single centre experience

BACKGROUND

Definition of ischemic cardiomyopathy (IC) is not always obvious, which is why new criteria based on prognosis and the extent of the coronary artery disease (CAD) have been proposed. In the present study, we assess the capability of late gadolinium-enhanced cardiovascular magnetic resonance (CMR) for predicting IC as determined by standardized criteria previously reported.

METHODS AND RESULTS

123 patients with heart failure (HF) and left ventricular (LV) systolic dysfunction, underwent both late gadolinium-enhanced CMR and coronary angiography 37/123 (30%) of patients were assigned to the IC group and 86/123 (70%) to the non-IC group. Subendocardial late gadolinium enhancement (LGE) was found in 35/37 (94%) of patients in the IC group, whereas only 12/86 (14%) had this distribution in the non-IC group (p<0.001). There was a significant positive correlation between the extent of subendocardial LGE and that of the CAD as determined by the CAD Prognostic Index (r=0.78, p<0.01), the number of coronary stenoses > or = 50% (r=0.76, p<0.01) and the number of coronary stenoses of any percentage (r=0.70, p<0.01).

CONCLUSION

In patients with HF and LV systolic dysfunction presence of subendocardial LGE makes an excellent indicator of underlying significant CAD, and the extent of the LGE correlates with the severity of the disease. It is therefore appealing as a method for diagnosing IC.

Detection of coronary artery stenosis using 40-channel computed tomography with multi-segment reconstruction

Coronary angiographic studies performed with 16-channel multidetector computer tomographic scanners have demonstrated accurate detection of coronary vessel stenosis but are limited by a significant number of non-evaluable segments. To date, only single-center experience with multidetector computer tomography has been reported. We performed a prospective, blinded study at 2 institutions to determine the feasibility and diagnostic accuracy of coronary angiography using 40-channel multidetector computer tomography with multi-segment reconstruction for the detection of obstructive coronary artery disease (CAD). Multidetector computer tomographic studies were performed in 85 patients who were referred for invasive coronary angiography with clinically suspected CAD. Datasets were analyzed by blinded, independent review. Of 1,145 segments that were suitable for analysis as determined by angiography, 1,045 (91.3%) were evaluable on multidetector computer tomography. Segment-based sensitivity, specificity, and positive and negative predictive values for detecting > or =50% luminal stenoses were 86%, 97%, 75%, and 97%, respectively. The area under the receiver-operating characteristic curves for the detection of > or =50% angiographic stenosis by multidetector computer tomography was 0.94. In a patient-based analysis, the sensitivity, specificity, and positive and negative predictive values for detecting subjects with > or =1 segment with > or =50% stenosis were 98%, 93%, 94% and 93%, respectively. In conclusion, coronary angiography using 40-channel multidetector computer tomography with multi-segment reconstruction accurately detects coronary segments and patients with obstructive CAD, with a small number of non-evaluable cases.

Evaluation of three-dimensional navigator-gated whole heart MR coronary angiography: The importance of systolic imaging in subjects with high heart rates

PURPOSE

To evaluate the influence of heart rate (HR) on magnetic resonance coronary angiography (MRCA) image quality in diastolic and systolic phases.

MATERIALS AND METHODS

Twenty-seven healthy volunteers (9 men; 33+/-9 years, HR 53-110 bpm), were evaluated with the electrocardiography and three-dimensional navigator-gating MRCA in a 1.5-T MR scanner (Avanto, Siemens) in diastolic and systolic phases (steady-state free precession; TR/TE/flip angle=3.2 ms/1.6 ms/90 degrees). The timing of scanning was individually adapted to the cardiac rest periods obtained in the prescanning, by visually identifying when the movement of right coronary artery was minimized during diastole and systole. Images of two phases were side-by-side compared on a four-point scale (from 1=poor to 4=excellent visibility; score of 3 or 4 as diagnostic).

RESULTS

Of 13 subjects with HR < or =65 bpm (low HR group, mean 59.8+/-4.9 bpm, range 53-65), the image quality scores were significantly better than that with higher heart rates (73.9+/-9.0 bpm, range 68-110) in diastolic MRCA. The image quality was significantly improved during systole in high HR group. Overall, 91.3% of low HR group had MRCA image of diagnostic quality acquired at diastole, while 88.3% of high HR group had diagnostic images at systole by segmental analysis (p=NS).

CONCLUSIONS

MRCA at systole offered superior quality in patients with high heart rates.

Coronary artery disease screening, treatment, and follow-up

Heart disease causes more than 30% of US deaths. Evidence-based screening allows a primary care physician to identify patients at risk before symptom onset. Estimating disease probability before screening affects which tests are appropriate. Low-risk adults should not be screened. ECG, exercise treadmill testing, cardiac stress imaging, electron beam computed tomography, and angiography are possible screening tests. Special populations may have additional screening indications. Management of patients who have coronary artery disease includes antiplatelet therapy; aggressive lipid lowering; management of hypertension with beta blockers and angiotensin-converting enzyme inhibitors; risk factor management, including smoking cessation, diet, and exercise; symptom management; and sometimes revascularization. Primary care physicians are well-suited to the monitoring and care of patients who have known coronary artery disease.

Anästhesie für Herzkatheteruntersuchungen bei Kindern

Cardiac catheterization in children with congenital heart disease or in adults with completely or partially corrected cardiac defects, is a growing field of activity for anaesthesiologists. This requires not only the willingness for interdisciplinary co-operation, but also detailed knowledge about the pathophysiology of congenital heart diseases. In interventional paediatric cardiology significant innovations have occurred during recent years including stenting of a patent ductus arteriosus and of peripheral pulmonary artery stenosis. Furthermore, radiofrequency catheter ablation for recurrent tachyarrhythmia, or resynchronisation therapy with biventricular pacing in the setting of congestive heart failure, or implantation of cardioverter defibrillators are increasingly being employed which require anaesthesia support.

Non-Invasive Detection of Coronary Artery Disease in Patients With Left Bundle Branch Block Using 64-Slice Computed Tomography

OBJECTIVES

The goal of this study was to evaluate the diagnostic accuracy of 64-slice computed tomography (CT) to identify coronary artery disease (CAD) in patients with complete left bundle branch block (LBBB).

BACKGROUND

Left bundle branch block increases risk of cardiac mortality, and prognosis is primarily determined by the underlying coronary disease. Non-invasive stress tests have limited performance, and conventional coronary angiography (CCA) is usually required.

METHODS

Sixty-six consecutive patients with complete LBBB and sinus rhythm admitted for CCA were enrolled. Computed tomography was performed 3 +/- 3.9 days before CCA. The accuracy of 64-slice CT to detect significant stenosis (>50% lumen narrowing) was compared with quantitative coronary angiography. All segments were analyzed regardless of image quality from coronary calcification or motion artifacts. Results were analyzed by patient and by coronary segment (990) using the American Heart Association 15-segment model.

RESULTS

Lower heart rates were associated with improved image quality. Computed tomography correctly identified 35 of 37 (95%) patients without significant stenosis and 28 of 29 (97%) patients with significant stenosis on CCA. Computed tomography correctly assessed 68 of 94 (72%) significant stenosis. Overall, accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 64-slice CT for identifying CAD by patient was 95%, 97%, 95%, 93%, and 97%, respectively, and by segment was 97%, 72%, 99%, 91%, and 97%, respectively.

CONCLUSIONS

In a routine clinical practice, 64-slice CT detects with excellent accuracy a significant CAD in patients with complete LBBB. A normal CT in this clinical setting is a robust tool to act as a filter and avoid invasive diagnostic procedures.

Variability in Fluoroscopic X-Ray Exposure in Contemporary Cardiac Catheterization Laboratories

OBJECTIVES

This study sought to assess fluoroscopic exposure rates in contemporary cardiac catheterization laboratories (CCL).

BACKGROUND

Increasing attention is being focused on X-ray exposure during diagnostic and therapeutic cardiovascular procedures.

METHODS

We measured fluoroscopic exposure rates (R/min) in 41 systems using a standardized methodology (National Electrical Manufacturers Association XR21 phantom). Measurements were obtained at 2 different phantom thicknesses to simulate varying patient body habitus.

RESULTS

Fluoroscopic exposure rates under medium (median 3.0 R/min, interquartile range 1.4 R/min) and large (median 12.5 R/min, interquartile range 4.8 R/min) habitus conditions showed substantial variation. Fluoroscopic exposure was associated with simulated patient habitus, X-ray system type, vendor, and geographic region. Under medium habitus conditions, only 25% of systems operated within a zone of lower than average exposure rates and satisfactory image quality; this frequency diminished to 7% under large habitus conditions (p < 0.001).

CONCLUSIONS

There is substantial variation (4- to 6-fold) in fluoroscopic exposure rates. This variation was not consistently associated with improved image quality. In the absence of a predictable benefit of higher (or lower) than average exposure rates, CCL quality improvement programs must minimize such potentially harmful variability in X-ray exposure.