Drugless and radiographer led: the start of a new era for CT coronary angiography.

OBJECTIVE: Since inception CT coronary angiography (CTCA) has required facilitating beta blockers (BB). However, CT technology has improved rapidly as has radiographer and reporter expertise. Using these factors, we instituted a radiographer led cardiac CT service (RLCCTS), without routine BB, which we studied for quality control (QC). METHODS: RLCCTS started October 2021 using a wide detector array CT system, with 20 min slots. QC study was registered with the clinical audit team, University Hospitals Plymouth, CA_2020-21-118. Uniform reporting was agreed including indication, BB administration, demographics, dose length product (DLP) and the coronary artery disease-reporting and data system (CAD-RADS) score. Uncertain CAD-RADS meant a non-diagnostic scan (NDS). Six months of data were collected; stable chest pain (SCP) patients, who have national CTCA QC comparators, were analysed using descriptive statistics. RESULTS: Of 1475 patients, 447 were not SCP patients-known CAD (157); valves (286); removed (4, data incomplete) leaving 1028 SCP patients CTCA for analysis. Demographics-mean age 63 years, body mass index 29, 50.4% women. BB therapy-four patients (two recalls). Overall, 36/1024 or 3.5% were NDS; median DLP 173mGy×cm; mean heart rate (HR) 70 bpm, 99/1024 or 9.7% HR >90 bpm (45% not sinus rhythm). CONCLUSIONS: Quality for RLCCTS was judged by NDS rate and DLP. National QC comparators suggest 4% NDS rate; median DLP for SCPP CTCA 209 mGy×cm. RLCCTS compares favourably. With modern cardiac CT, experienced radiographers and reporters, 'drugless' RLCCTS can deliver 20 min slot CTCA with satisfactory QC indicators.

United Kingdom standards for non-invasive cardiac imaging: recommendations from the Imaging Council of the British Cardiovascular Society.

Heart and circulatory diseases affect more than seven million people in the UK. Non-invasive cardiac imaging is a critical element of contemporary cardiology practice. Progressive improvements in technology over the last 20 years have increased diagnostic accuracy in all modalities and led to the incorporation of non-invasive imaging into many standard cardiac clinical care pathways. Cardiac imaging tests are requested by a variety of healthcare practitioners and performed in a range of settings from the most advanced hospitals to local health centres. Imaging is used to detect the presence and consequences of cardiovascular disease, as well as to monitor the response to therapies. The previous UK national imaging strategy statement which brought together all of the non-invasive imaging modalities was published in 2010. The purpose of this document is to collate contemporary standards developed by the modality-specific professional organisations which make up the British Cardiovascular Society Imaging Council, bringing together common and essential recommendations. The development process has been inclusive and iterative. Imaging societies (representing both cardiology and radiology) reviewed and agreed on the initial structure. The final document therefore represents a position, which has been generated inclusively, presents rigorous standards, is applicable to clinical practice and deliverable. This document will be of value to a variety of healthcare professionals including imaging departments, the National Health Service or other organisations, regulatory bodies, commissioners and other purchasers of services, and service users, i.e., patients, and their relatives.

Sex-based inequalities in contemporary UK hospital management of stable chest pain.

OBJECTIVE: We surveyed UK practice of National Institute for Health and Care Excellence (NICE) "Recent onset chest pain" guidance (CG95, 2016), stratified by sex. We looked for sex-related differences in referral to computed tomographic coronary angiography (CTCA) and subsequent functional imaging (FI), invasive coronary angiography (ICA) and revascularisation. METHODS: This was a prospective analysis of CTCA practice in 8 UK centres between 2018 and 2020. Coronary artery disease (CAD) was recorded with the CAD-reporting and data system. Local electronic records/archiving/communication systems were used to collect data regarding subsequent FI, ICA and revascularisation. RESULTS: 2301 women, 2326 men underwent CTCA; women were older (58±11 vs 55±12 years, p<0.001) but more likely to have normal coronary arteries (46% (1047) vs 29% (685); p<0.001) and less likely to have severe stenosis (7% (169) vs 13% (307); p<0.001). FI was used less for 4% (93) women, 5% (108) men; ICA was also used less for women (8% (182) vs 14% (321)), as was revascularisation (4% (83) vs 8% (177), p<0.001 for all), including those with ≥moderate CTCA stenosis undergoing ICA (53% (79) vs 61% (166); p<0.001). CONCLUSIONS: Women referred for a NICE CG95 (2016) CTCA are more likely to have normal coronary arteries and men more likely to have CAD. More men than women will then undergo ICA and revascularisation even after adjustments for CTCA disease severity. Raised awareness of these inequalities may improve contemporary chest pain care.

Downstream testing after CT coronary angiography: time for a rethink?

OBJECTIVE: We surveyed UK practice and compliance with the National Institute for Health and Care Excellence (NICE) 'recent-onset chest pain' guidance (Clinical Guideline 95, 2016) as a service quality initiative. We aimed to evaluate the diagnostic utility and efficacy of CT coronary angiography (CTCA), NICE-guided investigation compliance, invasive coronary angiography (ICA) use and revascularisation. METHODS: A prospective analysis was conducted in nine UK centres between January 2018 and March 2020. The reporter decided whether the CTCA was diagnostic. Coronary artery disease was recorded with the Coronary Artery Disease-Reporting and Data System (CAD-RADS). Local electronic records and picture archiving/communication systems were used to collect data regarding functional testing, ICA and revascularisation. Duplication of coronary angiography without revascularisation was taken as a surrogate for ICA overuse. RESULTS: 5293 patients (mean age, 57±12 years; body mass index, 29±6 kg/m²; 50% men) underwent CTCA, with a 96% diagnostic scan rate. 618 (12%) underwent ICA, of which 48% (298/618) did not receive revascularisation. 3886 (73%) had CAD-RADS 0-2, with 1% (35/3886) undergoing ICA, of which 94% (33/35) received ICA as a second-line test. 547 (10%) had CAD-RADS 3, with 23% (125/547) undergoing ICA, of which 88% (110/125) chose ICA as a second-line test, with 26% (33/125) leading to revascularisation. For 552 (10%) CAD-RADS 4 and 91 (2%) CAD-RADS 5 patients, ICA revascularisation rates were 64% (221/345) and 74% (46/62), respectively. CONCLUSIONS: While CTCA for recent-onset chest pain assessment has been shown to be a robust test, which negates the need for further investigation in three-quarters of patients, subsequent ICA overuse remains with almost half of these procedures not leading to revascularisation.

CT imaging prior to transcatheter aortic valve implantation in the UK.

Objective: This cross-sectional observational study sought to describe variations in CT in the context of transcatheter aortic valve implantation (CT-TAVI) as currently performed in the UK. Methods: 408 members of the British Society of Cardiovascular Imaging were invited to complete a 27-item online CT-TAVI survey. Results: 47 responses (12% response rate) were received from 40 cardiac centres, 23 (58%) of which performed TAVI on-site (TAVI centres). Only six respondents (13%) performed high-volume activity (>200 scans per year) compared with 13 (28%) performing moderate (100-200 scans per year) and 27 (59%) performing low (0-99 scans per year) volume activity. Acquisition protocols varied (41% retrospective, 12% prospective with wide padding, 47% prospective with narrow padding), as did the phase of reporting (45% systolic, 37% diastolic, 11% both, 6% unreported). Median dose length product was 675 mGy.cm (IQR 477-954 mGy.cm). Compared with non-TAVI centres, TAVI centres were more likely to report minimum iliofemoral luminal diameter (n=25, 96% vs n=7, 58%, p=0.003) and optimal tube angulation for intervention (n=12, 46% vs n=1, 8%, p=0.02). Conclusions: This national survey formally describes current CT-TAVI practice in the UK. High-volume activity was only present at one in seven cardiac CT centres. There is wide variation in scan acquisition, scan reporting and radiation dose exposure in cardiac CT centres.

Complementary role of cardiac CT in the assessment of aortic valve replacement dysfunction.

Aortic valve replacement is the second most common cardiothoracic procedure in the UK. With an ageing population, there are an increasing number of patients with prosthetic valves that require follow-up. Imaging of prosthetic valves is challenging with conventional echocardiographic techniques making early detection of valve dysfunction or complications difficult. CT has recently emerged as a complementary approach offering excellent spatial resolution and the ability to identify a range of aortic valve replacement complications including structural valve dysfunction, thrombus development, pannus formation and prosthetic valve infective endocarditis. This review discusses each and how CT might be incorporated into a multimodal cardiovascular imaging pathway for the assessment of aortic valve replacements and in guiding clinical management.

Multimodality imaging in heart valve disease.

In patients with heart valve disease, echocardiography is the mainstay for diagnosis, assessment and serial surveillance. However, other modalities, notably cardiac MRI and CT, are used if echocardiographic imaging is suboptimal but can also give complementary information to improve assessment of the valve lesion and cardiac compensation to aid the timing of surgery and determine risk. This statement discusses the way these imaging techniques are currently integrated to improve care beyond what is possible with echocardiography alone.

Recommendations for accurate CT diagnosis of suspected acute aortic syndrome (AAS)--on behalf of the British Society of Cardiovascular Imaging (BSCI)/British Society of Cardiovascular CT (BSCCT).

Accurate and timely assessment of suspected acute aortic syndrome is crucial in this life-threatening condition. Imaging with CT plays a central role in the diagnosis to allow expedited management. Diagnosis can be made using locally available expertise with optimized scanning parameters, making full use of recent advances in CT technology. Each imaging centre must optimize their protocols to allow accurate diagnosis, to optimize radiation dose and in particular to reduce the risk of false-positive diagnosis that may simulate disease. This document outlines the principles for the acquisition of motion-free imaging of the aorta in this context.

CT coronary angiography in atrial fibrillation: a comparison of radiation dose and diagnostic confidence with retrospective gating vs prospective gating with systolic acquisition.

OBJECTIVE: To compare unmodulated, retrospective electrocardiographic (ECG) gating to prospective ECG gating with systolic acquisition for CT coronary angiography (CTCA) in patients with atrial fibrillation (AF), considering the radiation dose and the diagnostic confidence achieved with each technique. METHODS: A retrospective service evaluation was conducted before and after prospective gating with systolic acquisition replaced retrospectively gated imaging for patients with AF undergoing CTCA at our institution. 25 consecutive patients were examined in each group. The scan parameters and radiation dose information had been collected in a prospective fashion. The image sets were read by blinded, expert readers who rated their diagnostic confidence using a 5-point Likert scale. RESULTS: The radiation dose received by patients was significantly greater in the retrospectively gated group than those being scanned using prospective gating (21 vs 5.9 mSv, p < 0.01). The prospective gating technique was also associated with greater diagnostic confidence (mean, per-patient score 3.09 vs 3.78, p = 0.02). CONCLUSION: Prospective gating with systolic acquisition appears to improve diagnostic confidence at a significantly reduced radiation dose compared with retrospective gating in patients with AF. ADVANCES IN KNOWLEDGE: The use of prospective gating with systolic triggering significantly reduces the radiation exposure to patients in AF undergoing CTCA. The same protocol also appears to improve diagnostic confidence.

Safety of intravenous ß-adrenoceptor blockers for computed tomographic coronary angiography.

AIMS: To assess the safety of our clinical practice using off-label intravenous metoprolol to facilitate computed tomographic (CT) coronary angiography. METHODS: A retrospective analysis of scan reports and hospital admissions data was conducted to identify adverse events occurring following CT coronary angiography in patients who had received intravenous metoprolol prior to the scan. RESULTS: A total of 3098 patients were included, of whom 1871 received intravenous metoprolol. Nine hundred and one patients received more than 15 mg and 129 patients received metoprolol despite a resting heart rate <65 beats min(-1) . There was a single adverse incident, comprising transient loss of consciousness. CONCLUSIONS: The use of intravenous metoprolol to facilitate cardiac CT scanning appears safe. Dose limits recommended for other indications, generally in acutely unwell patients, may not need to be as stringent in this population.

Cardiac imaging to investigate suspected cardiac pain in the post-treadmill era.

Symptomatic cardiovascular disease is one of the leading causes of hospital admissions in the UK; along with emergency attendances, over 100,000 patients are investigated using treadmill testing via rapid access chest pain clinics each year. With the introduction of new technologies, clinicians have a wide choice of investigations including nuclear perfusion scanning, dobutamine stress echocardiography, cardiac computed tomography and stress cardiac magnetic resonance imaging. These imaging modalities have their strengths and weaknesses, which depend not only on the pre-test likelihood of significant coronary artery disease but also the clinical characteristics of the patient. This article will review the differing imaging modalities, the patient experience, accuracy, prognostic data and future prospects for cardiac computed tomography and magnetic resonance imaging.

Assessment of the myocardium with cardiac computed tomography.

The imaging of myocardial disease is of increasing importance for cardiologists from all subspecialties, for diagnosis, risk stratification, or to facilitate therapy. While the gold standard modalities for such assessment are cardiac magnetic resonance and echocardiography, these are not universally suitable. Cardiac computed tomography (CT), well-established for the assessment of coronary artery disease (CAD), can be of value in the assessment of myocardial pathology, due to excellent patient compatibility and tolerability, high spatial resolution, and acceptable tissue characterization. This review considers the value and limitations of CT in the assessment of the myocardial sequelae of CAD, and for patients with a variety of other cardiomyopathic diseases, depicts some of the common findings, and considers current developments in this area.

Coronary arterial microfistulae: a CT coronary angiography perspective.

Coronary arterial microfistulae are abnormal connections between one or multiple coronary arteries and any cardiac chamber, vein, or thoracic vessel. They comprise a subsection of coronary fistulas where the abnormal connections are diffuse, as opposed to the larger, more common single vessel varieties. Most of these anomalies are detected incidentally on catheter angiography; however, we present this anomaly as a case report from the perspective of CT coronary angiography.

Usefulness of 64-detector row computed tomography for evaluation of intracoronary stents in symptomatic patients with suspected in-stent restenosis.

To determine whether 64-slice multidetector computed tomographic coronary angiography (MDCTA) can accurately assess the coronary artery lumen in symptomatic patients with previous coronary artery stents and potential in-stent restenosis (ISR). The primary aim was to determine the accuracy of binary ISR exclusion using MDCTA compared with invasive catheter angiography (ICA). Secondary aims were comparisons of stent dimensions measured using MDCTA and variables that affect accuracy. Forty patients with previous stent placement underwent both ICA and 64-slice MDCTA after elective presentation with chest pain, and ICA quantitative coronary angiographic data were used as the reference standard. Thirty-six men and 4 women (age 64 +/- 10 years; range 44 to 83) with 103 stents (2.8 +/- 1.6 stents/patient) were comparatively evaluated (stent exclusion rate 9.6%). There were 45 bare-metal and 58 drug-eluting stents (20 +/- 18 months after implantation) with an average diameter of 3.23 +/- 0.7 mm. Overall accuracy for the detection of significant ISR showed sensitivity, specificity, and positive and negative predictive values of 85%, 86%, 61%, and 96% for proximal stents > or =3 mm, which improved to 100%, 94%, 81%, and 100%; if the visible luminal diameter on MDCTA was <1.5 mm, accuracy decreased to 40%, 84%, 29%, and 90%, respectively. In conclusion, 64-slice MDCTA assessment of symptomatic patients with suspected clinically significant ISR is a realistic alternative to ICA if reference stent diameter is > or =2.5 mm and visible lumen cross-sectional diameter is > or =1.5 mm, for which a negative MDCTA result virtually excludes the presence of significant ISR.

Dilatation of the aorta in pure, severe, bicuspid aortic valve stenosis.

BACKGROUND: Aortic complications are more frequent after bicuspid aortic valve (BAV) replacement (AVR), than tricuspid aortic valve replacement. We studied the size of the proximal thoracic aorta in patients with BAV undergoing AVR for pure, severe aortic stenosis, looking for dilatation in comparison with patients with a matched tricuspid aortic valve (TAV) and normograms of aortic size. METHODS: Aortic root and ascending aortic diameter measurements were taken at 3 levels, from electrocardiographic-gated multidetector row computed tomograms, in 28 patients with pure, severe aortic stenosis before AVR. The patients were divided in 2 groups (BAV, n = 10; TAV, n = 18). Patients with greater than mild aortic regurgitation or who were scheduled for aortic root replacement were excluded. RESULTS: Although patients in the BAV group were younger (P <.0001) and less likely to have hypertension (P <.005), their aortic diameters were larger than those of patients in the TAV group at all levels measured (aortic sinus, 41.1 +/- 8.1 mm vs 33.8 +/- 3.3 mm; sino-tubular junction, 39.0 +/- 7.8 mm vs 31.1 +/- 3.8 mm; right pulmonary artery level, 42.8 +/- 7.1 mm vs 33.7 +/- 4.3 mm; P <.005 for all). Whereas 60% (6/10) of patients in the BAV group had >/=1 aortic diameter measurements greater than the 95th age-adjusted percentile, 0% (0/18) of patients in the TAV group did. CONCLUSIONS: Patients with BAV undergoing AVR with pure, severe aortic stenosis commonly have moderate dilatation of the thoracic aorta, whereas matched patients with a TAV do not. This finding may contribute to the increased frequency of aortic complications seen in follow up of patients with a BAV after AVR.