P.A. Ball

A comparison of cardiac computerized tomography and exercise stress electrocardiogram test for the investigation of stable chest pain: the clinical results of the CAPP randomized prospective trial.

AIMS To determine the symptomatic and prognostic differences resulting from a novel diagnostic pathway based on cardiac computerized tomography (CT) compared with the traditional exercise stress electrocardiography test (EST) in stable chest pain patients. METHODS AND RESULTS A prospective randomized controlled trial compared selected patient outcomes in EST and cardiac CT coronary angiography groups. Five hundred patients with troponin-negative stable chest pain and without known coronary artery disease were recruited. Patients completed the Seattle Angina Questionnaires (SAQ) at baseline, 3, and 12 months to assess angina symptoms. Patients were also followed for management strategies and clinical events. Over the year 12 patients withdrew, resulting in 245 in the EST cohort and 243 in the CT cohort. There was no significant difference in baseline demographics. The CT arm had a statistical difference in angina stability and quality-of-life domains of the SAQ at 3 and12 months, suggesting less angina compared with the EST arm. In the CT arm, there was more significant disease identified and more revascularizations. Significantly, more inconclusive results were seen in the EST arm with a higher number of additional investigations ordered. There was also a longer mean time to management. There were no differences in major adverse cardiac events between the cohorts. At 1 year in the EST arm, there were more Accident and Emergency (A&E) attendances and cardiac admission. CONCLUSION Cardiac CT as an index investigation for stable chest pain improved angina symptoms and resulted in fewer investigations and re-hospitalizations compared with EST. CLINICAL TRIAL REGISTRATION http://www.controlled-trials.com/ISRCTN52480460.

The cost-effectiveness of cardiac computed tomography for patients with stable chest pain

Objective To assess the cost-effectiveness of cardiac CT compared with exercise stress testing (EST) in improving the health-related quality of life of patients with stable chest pain. Methods A cost–utility analysis alongside a single-centre randomised controlled trial carried out in Northern Ireland. Patients with stable chest pain were randomised to undergo either cardiac CT assessment or EST (standard care). The main outcome measure was cost per quality adjusted life year (QALY) gained at 1 year. Results Of the 500 patients recruited, 250 were randomised to cardiac CT and 250 were randomised to EST. Cardiac CT was the dominant strategy as it was both less costly (incremental total costs −£50.45; 95% CI −£672.26 to £571.36) and more effective (incremental QALYs 0.02; 95% CI −0.02 to 0.05) than EST. At a willingness-to-pay threshold of £20 000 per QALY the probability of cardiac CT being cost-effective was 83%. Subgroup analyses indicated that cardiac CT appears to be most cost-effective in patients with a likelihood of coronary artery disease (CAD) of <30%, followed by 30%–60% and then >60%. Conclusions Cardiac CT is cost-effective compared with EST and cost-effectiveness was observed to vary with likelihood of CAD. This finding could have major implications for how patients with chest pain in the UK are assessed, however it would need to be validated in other healthcare systems. Trial registration number (ISRCTN52480460); results.

Serum- and HDL3-serum amyloid A and HDL3-LCAT activity are influenced by increased CVD-burden

BACKGROUND High density lipoproteins (HDL) protect against cardiovascular disease (CVD). However, increased serum amyloid-A (SAA) related inflammation may negate this property. This study investigated if SAA was related to CVD-burden. METHODS Subjects referred to the rapid chest pain clinic (n = 240) had atherosclerotic burden assessed by cardiac computerised tomography angiography. Subjects were classified as: no-CVD (n = 106), non-obstructive-CVD, stenosis<50% (n = 58) or moderate/significant-CVD, stenosis ≥50% (n = 76). HDL was subfractionated into HDL2 and HDL3 by rapid-ultracentrifugation. SAA-concentration was measured by ELISA and lecithin cholesterol acyltransferase (LCAT) activity measured by a fluorimetric assay. RESULTS We illustrated that serum-SAA and HDL3-SAA-concentration were higher and HDL3-LCAT-activity lower in the moderate/significant-CVD-group, compared to the no-CVD and non-obstructive-CVD-groups (percent differences: serum-SAA, +33% & +30%: HDL3-SAA, +65% and +39%: HDL3-LCAT, -6% & -3%; p < 0.05 for all comparisons). We also identified a positive correlation between serum-SAA and HDL3-SAA (r = 0.698; p < 0.001) and a negative correlation between HDL3-SAA and HDL3-LCAT-activity (r = -0.295; p = 0.003), while CVD-burden positively correlated with serum-SAA (r = 0.150; p < 0.05) and HDL3-SAA (r = 0.252; p < 0.001) and negatively correlated with HDL3-LCAT-activity (r = -0.182; p = 0.006). Additionally, multivariate regression analysis adjusted for age, gender, CRP and serum-SAA illustrated that HDL3-SAA was significantly associated with modifying CVD-risk of moderate/significant CVD-risk (p < 0.05). CONCLUSION This study has demonstrated increased SAA-related inflammation in subjects with moderate/significant CVD-burden, which appeared to impact on the antiatherogenic potential of HDL. We suggest that SAA may be a useful biomarker to illustrate increased CVD-burden, although this requires further investigation.

096 A comparative study of standard filtered back projection with novel iterative reconstruction techniques in cardiac CT

Background Iterative reconstruction (IR) is a novel but significant development in CT image acquisition. There have been a number of studies that have reported on the potential of IR in cardiac CT. These retrospectively applied IR in the image domain to images acquired with standard filtered back projection (FBP) techniques. This study was part of an ongoing randomised control trial [ISRCTN52480460] evaluating the cost effectiveness of cardiac CT. Methods 250 patients were prospectively enrolled to have a cardiac CT for the investigation of stable chest pain. Written and informed consent was obtained. Data acquisition were performed on a Philips Brilliance 64. The patients were divided into two groups. Cohort A underwent standard FBP imaging, and Cohort B underwent IR with Idose® (Philips, Cleveland, Ohio, USA). Within each cohort the scan parameters (kv, mAs, pitch) and reconstruction protocols (prospective or retrospective) were determined by patient characteristics. Images were assessed for noise and signal quality within regions of interest (ROI) on axial images, and subjectively for image quality by two experienced readers. Noise was defined as the SD of the measured HU, and signal as the HU mean attenuation value. The ROIs were in the ascending aorta, interventricular septum and left ventricular cavity. Subjective image quality was rated blindly using a 5-point Likert scale. Effective radiation dose (ED) of each CTCA was estimated by multiplying the dose-length product by a chest-specific conversion coefficient (κ=0.014 mSv×mGy−1×cm−1). Results Of the 250 patients enrolled 3 withdrew. 146 of the 247 subjects were male with a mean age of 57.93 (SD 9.93). Cohort A consisted of 124 patients, and cohort B 123, with no significant difference in baseline demographics. The mean dose of all FBP was 6.09 mSv, (SD 3.16) compared to an IR mean of 4.23 mSv, (SD 2.01) which was a dose saving of 1.86 mSv (30.54%). This was a significant dose reduction (p value <0.0001.) Mean image quality score obtained from the IR images was 3.67 (SD 1.04) compared to the FBP images of 3.29 (SD 1.17) p value of 0.0067. There was good agreement between the readers—κ coefficient 0.83. Cohort A consisted of 74 retrospective images and 50 prospective. Cohort B had 116 with retrospective and 7 with prospective. The mean ED for a prospective FBP was 3.50 mSv (SD 1.15), with the IR equivalent being 2.00 mSv (0.72), giving a mean dose saving of 1.50 mSv (42.86%). The mean ED for FBP retrospective studies was 7.85 mSv (SD 2.87), with the IR equivalent being 4.36 mSv (SD 1.99), with a mean dose saving of 3.49 mSv (44.46%). There was no statistical difference in noise or mean attenuation between the IR and FBP images in all three areas of interest Abstract 096 table 1.Abstract 096 Table 1 Region of interest Image noise Attenuation FBP IR p Value FBP IR p Value Ascending aorta 29.76±32.00 27.33±10.10 0.42 505.85±95.64 520.72±103.07 0.24 Interventricular septum 28.96±9.63 28.27±7.53 0.53 154.76±35.28 153.63±32.41 0.79 Left ventricle 29.78±9.36 28.55±12.39 0.38 464.27±92.50 484.07±99.38 0.11 Conclusions To our knowledge this is the first study to prospectively compare FBP with IR. It suggests that cardiac IR protocols confer a substantial radiation dose reduction without a compromise in diagnostic quality.

5 Real world experience of a novel on-site coronary ct derived fractional flow reserve algorithm for the assessment of intermediate stenoses

Objective Fractional flow reserve derived from coronary CT angiography (FFR-CT) is a novel tool for assessing the significance of coronary artery stenosis. The primary aim of this prospective study was to evaluate the diagnostic performance of a novel on-site rapid FFR-CT algorithm as compared to invasive FFR as the gold standard in a real world workflow. Our secondary aim was to determine whether the FFR-CT diagnostic performance was affected by inter-observer variations in lumen segmentation. Methods We enrolled 44 consecutive patients (64.6 ±8.9 years, 34% female) with 60 coronary atherosclerotic lesions who underwent coronary computed tomography angiography (CTA) and were referred for invasive coronary angiography (ICA) in two European centres. ICA with FFR measurements were performed within 60 days after coronary CTA in all lesions. An FFR value of ≤0.8 was considered significant. Coronary CTA scans were evaluated by two expert readers, who determined the effective diameter stenosis (EDS) and manually adjusted the semi-automated coronary lumen segmentations. All extracted vessels were evaluated by an on-site FFR simulator to calculate the FFR-CT values. Results The mean FFR-CT value was 0.77 ±0.15 and the average coronary CTA based EDS was 43.6±16.9%. On-site lumen segmentation, manual adjustment and FFR-CT simulations were performed in an average of 9 minutes, (range: 3–25 min). The sensitivity, specificity, positive predictive value and negative predictive value of FFR-CT vs. EDS with a cut-off of 50% were the following: 90.5%, 71.8%, 63.3% and 93.3% vs. 52.4%, 87.2%, 68.8% and 77.3%. FFR-CT demonstrated significantly better diagnostic performance as compared to EDS (AUC: 0.89 vs. 0.74 respectively; p<0.001). The FFR-CT AUCs of the two readers did not show any significant difference (0.89 vs. 0.88; p=0.74). Conclusion On-site FFR-CT simulation is feasible and has better diagnostic performance than anatomical stenosis assessment. The diagnostic performance of the FFR-CT simulation algorithm does not depend on the readers who adjust the semi-automated lumen segmentation adjustments.

A comparison of Functional and Anatomical Investigations with Angina Symptoms: Results from a Randomised Controlled Trial

The presence of angina is a potential source of reduced quality of life and may be a predictor of adverse cardiovascular outcomes. Recent guidelines suggest that management of angina should revolve around the use of the Diamond Forrester (DF) score to determine which tests should be used for an individual patient. The choice of test can be broadly categorized into anatomical or function. Little is known about how either type of test correlates with the DF score. This study was part of a larger randomized Controlled Trial to compare the use of cardiac Computerized Tomography (CT) and exercise Electrocardiogram Stress Test (EST) in patients with stable angina. This analysis compared the results from EST and CT against the DF scores. Overall all results showed that there is a poor correlation between DF and both tests. R-squared value from the linear model showed correlation between EST and DF scores to be 0.315, with the correlation between CT and DF scores 0.415. This calls into question the useful of symptoms to drive investigations. Received Date: April 13, 2016 Accepted Date: May 20, 2016 Published Date: May 26, 2016 Citation: McKavanagh, P., et al. A Comparison of Functional and Anatomical Investigations with Angina Symptoms: Results from a Randomized Controlled Trial. (2016) J Heart Cardiol 2(2): 17. McKavanagh, P., et al.

The Essentials of Cardiac Computerized Tomography.

Cardiac computerized tomography (CT) has evolved from a research tool to an important diagnostic investigation in cardiology, and is now recommended in European, US, and UK guidelines. This review is designed to give the reader an overview of the current state of cardiac CT. The role of cardiac CT is multifaceted, and includes risk stratification, disease detection, coronary plaque quantification, defining congenital heart disease, planning for structural intervention, and, more recently, assessment of ischemia. This paper addresses basic principles as well as newer evidence.