Low-level elevations in high-sensitivity cardiac troponin predict obstructive coronary artery disease and revascularisation in rural patients with non-ST-elevation myocardial infarction referred for coronary angiography.

Rural patients with non-ST-elevation myocardial infarction (NSTEMI) are transferred to metropolitan hospitals for invasive coronary angiography (ICA). Yet, many do not have obstructive coronary artery disease (CAD). In this analysis of rural Western Australian patients transferred for ICA for NSTEMI, low-level elevations in high-sensitivity cardiac troponin (≤5× upper reference limit) were associated with less obstructive CAD and revascularisation. Along with other factors, this may help identify rural patients not requiring transfer for ICA.

Telehealth during COVID-19 restrictions in patients with cardiovascular disease: impact on medication prescriptions and patient satisfaction.

BACKGROUND AND AIMS: Telehealth plays an integral part in healthcare delivery. The impact of telehealth and the COVID-19 pandemic on medication prescribing and patient satisfaction with telehealth in cardiology clinics remains unknown. METHODS: A retrospective study of cardiology clinic patients at an Australian tertiary hospital was conducted; 630 patients seen before the COVID-19 pandemic (0.6% telehealth) and 678 during the pandemic (91.2% telehealth) were included. Medication changes, new prescriptions and time to obtaining prescriptions after clinic were compared. To evaluate patients' experiences, cardiology clinic patients reviewed during the pandemic were prospectively invited to participate in an electronic survey sent to their mobile phones. RESULTS: The overall rates of medication changes made in the clinic between the prepandemic and the pandemic periods did not differ significantly (26.9% vs 25.8%). Compared with prepandemic, new cardiac medication prescriptions during clinic were significantly less (9.3% vs 2.5%; P < 0.0001) and recommendations to general practitioners (GP) to initiate cardiac medications were significantly more (2.6% vs 9.1%; P < 0.0001). Time to obtaining new prescriptions was significantly longer in the pandemic cohort (median 0 days (range: 0-32) vs 10.5 days (range: 0-231); P < 0.0001). Two hundred forty-three (32.7%) patients participated in the survey; 50% reported that telehealth was at least as good as face-to-face consultations. Most patients (61.5%) were satisfied with telehealth and most (62.9%) wished to see telehealth continued postpandemic. CONCLUSION: Telehealth during the COVID-19 pandemic was associated with greater reliance on GP to prescribe cardiac medications and delays in obtaining prescriptions among cardiology clinic patients. Although most patients were satisfied with telehealth services, nearly half of the cardiac patients expressed preference towards traditional face-to-face consultations.

Evaluation of an artificial intelligence coronary artery calcium scoring model from computed tomography.

OBJECTIVES: Coronary artery calcium (CAC) scores derived from computed tomography (CT) scans are used for cardiovascular risk stratification. Artificial intelligence (AI) can assist in CAC quantification and potentially reduce the time required for human analysis. This study aimed to develop and evaluate a fully automated model that identifies and quantifies CAC. METHODS: Fully convolutional neural networks for automated CAC scoring were developed and trained on 2439 cardiac CT scans and validated using 771 scans. The model was tested on an independent set of 1849 cardiac CT scans. Agatston CAC scores were further categorised into five risk categories (0, 1-10, 11-100, 101-400, and > 400). Automated scores were compared to the manual reference standard (level 3 expert readers). RESULTS: Of 1849 scans used for model testing (mean age 55.7 ± 10.5 years, 49% males), the automated model detected the presence of CAC in 867 (47%) scans compared with 815 (44%) by human readers (p = 0.09). CAC scores from the model correlated very strongly with the manual score (Spearman's r = 0.90, 95% confidence interval [CI] 0.89-0.91, p < 0.001 and intraclass correlation coefficient = 0.98, 95% CI 0.98-0.99, p < 0.001). The model classified 1646 (89%) into the same risk category as human observers. The Bland-Altman analysis demonstrated little difference (1.69, 95% limits of agreement: -41.22, 44.60) and there was almost excellent agreement (Cohen's κ = 0.90, 95% CI 0.88-0.91, p < 0.001). Model analysis time was 13.1 ± 3.2 s/scan. CONCLUSIONS: This artificial intelligence-based fully automated CAC scoring model shows high accuracy and low analysis times. Its potential to optimise clinical workflow efficiency and patient outcomes requires evaluation. KEY POINTS: • Coronary artery calcium (CAC) scores are traditionally assessed using cardiac computed tomography and require manual input by human operators to identify calcified lesions. • A novel artificial intelligence (AI)-based model for fully automated CAC scoring was developed and tested on an independent dataset of computed tomography scans, showing very high levels of correlation and agreement with manual measurements as a reference standard. • AI has the potential to assist in the identification and quantification of CAC, thereby reducing the time required for human analysis.

Clinical outcomes and health care costs of transferring rural Western Australians for invasive coronary angiography, and a cost-effective alternative care model: a retrospective cross-sectional study.

OBJECTIVES: To examine the severity of coronary artery disease (CAD) in people from rural or remote Western Australia referred for invasive coronary angiography (ICA) in Perth and their subsequent management; to estimate the cost savings were computed tomography coronary angiography (CTCA) offered in rural centres as a first line investigation for people with suspected CAD. DESIGN: Retrospective cohort study. SETTING, PARTICIPANTS: Adults with stable symptoms in rural and remote WA referred to Perth public tertiary hospitals for ICA evaluation during the 2019 calendar year. MAIN OUTCOME MEASURES: Severity and management of CAD (medical management or revascularisation); health care costs by care model (standard care or a proposed alternative model with local CTCA assessment). RESULTS: The mean age of the 1017 people from rural and remote WA who underwent ICA in Perth was 62 years (standard deviation, 13 years); 680 were men (66.9%), 245 were Indigenous people (24.1%). Indications for referral were non-ST elevation myocardial infarction (438, 43.1%), chest pain with normal troponin level (394, 38.7%), and other (185, 18.2%). After ICA assessment, 619 people were medically managed (60.9%) and 398 underwent revascularisation (39.1%). None of the 365 patients (35.9%) without obstructed coronaries (< 50% stenosis) underwent revascularisation; nine patients with moderate CAD (50-69% stenosis; 7%) and 389 with severe CAD (≥ 70% stenosis or occluded vessel; 75.5%) underwent revascularisation. Were CTCA used locally to determine the need for referral, 527 referrals could have been averted (53%), the ICA:revascularisation ratio would have improved from 2.6 to 1.6, and 1757 metropolitan hospital bed-days (43% reduction) and $7.3 million in health care costs (36% reduction) would have been saved. CONCLUSION: Many rural and remote Western Australians transferred for ICA in Perth have non-obstructive CAD and are medically managed. Providing CTCA as a first line investigation in rural centres could avert half of these transfers and be a cost-effective strategy for risk stratification of people with suspected CAD.

Artificial Intelligence in Cardiology: An Australian Perspective.

Significant advances have been made in artificial intelligence technology in recent years. Many health care applications have been investigated to assist clinicians and the technology is close to being integrated into routine clinical practice. The high prevalence of cardiac disease in Australia places overwhelming demands on the existing health care system, challenging its capacity to provide quality patient care. Artificial intelligence has emerged as a promising solution. This discussion paper provides an Australian perspective on the current state of artificial intelligence in cardiology, including the benefits and challenges of implementation. This paper highlights some current artificial intelligence applications in cardiology, while also detailing challenges such as data privacy, ethical considerations, and integration within existing health infrastructures. Overall, this paper aims to provide insights into the potential benefits of artificial intelligence in cardiology, while also acknowledging the barriers that need to be addressed to ensure safe and effective implementation into an Australian health system.

Contemporary Chest Pain Evaluation: The Australian Case for Cardiac CT.

Computed tomography coronary angiography (CTCA) is a non-invasive diagnostic modality that provides a comprehensive anatomical assessment of the coronary arteries and coronary atherosclerosis, including plaque burden, composition and morphology. The past decade has witnessed an increase in the role of CTCA for evaluating patients with both stable and acute chest pain, and recent international guidelines have provided increasing support for a first line CTCA diagnostic strategy in select patients. CTCA offers some advantages over current functional tests in the detection of obstructive and non-obstructive coronary artery disease, as well as for ruling out obstructive coronary artery disease. Recent randomised trials have also shown that CTCA improves prognostication and guides the use of guideline-directed preventive therapies, leading to improved clinical outcomes. CTCA technology advances such as fractional flow reserve, plaque quantification and perivascular fat inflammation potentially allow for more personalised risk assessment and targeted therapies. Further studies evaluating demand, supply, and cost-effectiveness of CTCA for evaluating chest pain are required in Australia. This discussion paper revisits the evidence supporting the use of CTCA, provides an overview of its implications and limitations, and considers its potential role for chest pain evaluation pathways in Australia.

Diagnostic Performance of CT-Derived Fractional Flow Reserve in Australian Patients Referred for Invasive Coronary Angiography.

BACKGROUND: Non-invasive computed tomography (CT)-derived fractional flow reserve (FFRCT) is computed from standard coronary CT angiography (CTA) datasets and provides accurate vessel-specific ischaemia assessment of coronary artery disease (CAD). To date, the technique and its diagnostic performance has not been verified in the Australian clinical context. The aim of this study was to describe and compare the diagnostic performance of FFRCT and CTA for the detection of vessel-specific ischaemia as determined by invasive fractional flow reserve (FFR) in the Australian patient population. METHODS: One-hundred-and-nine patients (219 vessels) referred for clinically mandated invasive angiography were retrospectively assessed. Each patient underwent research mandated CTA and FFRCT within 3 months of invasive angiography and invasive FFR assessment. Independent core laboratory assessments were made to determine visual CTA stenosis, FFRCT and invasive FFR values. FFRCT values were matched with the corresponding invasive FFR measurement taken at the given wire position. Visual CTA stenosis ≥50%, FFRCT values ≤0.8 and invasive FFR values ≤0.8 were considered significant for ischaemia. RESULTS: Per vessel accuracy, sensitivity, specificity, positive predictive value and negative predictive value of FFRCT were 80.4%, 80.0%, 80.6%, 64.9% and 90.0% respectively. Corresponding values for CTA were 75.1%, 87.1%, 69.2%, 58.1% and 91.7% respectively. In receiver operating characteristic curve analysis, FFRCT demonstrated superior area under the curve (AUC) compared with CTA in both per vessel (0.87 vs 0.77, p=0.004) and per patient analysis (0.86 vs 0.74, p=0.011). Per vessel AUC of combined CTA and FFRCT was superior to CTA alone (0.89 vs 0.77, p<0.0001). CONCLUSION: In this cohort of Australian patients, the diagnostic performance of FFRCT was found to be comparable to existing international literature, with demonstrated improvement in performance compared with CTA alone for the detection of vessel-specific ischaemia.

Contemporary Evidence-Based Diagnosis and Management of Severe Coronary Artery Calcification.

Percutaneous treatment of heavily calcified coronary lesions remains a challenge for interventional cardiologists with increased risk of incomplete lesion preparation, suboptimal stent deployment, procedural complications, and a higher rate of acute and late stent failure. Adequate lesion preparation through calcium modification is crucial in optimising procedural outcomes. Several calcium modification devices and techniques exist, with rotational atherectomy the predominant treatment for severely calcified lesions. Novel technologies such as intravascular lithotripsy are now available and show promise as a less technical and highly effective approach for calcium modification. Emerging evidence also emphasises the value of detailed characterisation of calcification severity and distribution especially with intracoronary imaging for appropriate device selection and individualised treatment strategy. This review aims to provide an overview of the non-invasive and invasive evaluation of coronary calcification, discuss calcium modification techniques and propose an algorithm for the management of calcified coronary lesions.

Women With Spontaneous Coronary Artery Dissection Are at Increased Risk of Iatrogenic Coronary Artery Dissection.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is a non-atherosclerotic cause of acute coronary syndrome (ACS) that affects women disproportionately. Previous case series have found that patients with SCAD undergoing cardiac catheterisation have high rates of iatrogenic coronary damage. We formally compared the rate of iatrogenic coronary artery dissection in women with and without SCAD undergoing cardiac catheterisation over a 11-year period. METHODS: Women with SCAD were identified by a search of the cardiac catheterisation database 2007-2017 for the keywords 'SCAD', 'spontaneous coronary artery dissection', 'spontaneous coronary dissection', and 'spontaneous dissection'. For each identified case, the medical record and the coronary angiogram images were reviewed to confirm spontaneous coronary dissection. For cases of recurrent SCAD, duplicates were removed so that each patient was included only once in this analysis. For each identified case of SCAD, a control case was chosen from women aged <70 years, without SCAD, undergoing cardiac catheterisation for an ACS during the same 10-year period. One control case was chosen to match each SCAD patient as closely as possible for age and year of cardiac catheterisation. Iatrogenic coronary dissection was defined as new, proximal, flow limiting coronary artery dissection in a different coronary segment to the presenting spontaneous coronary dissection. RESULTS: Eighty-five (85) cases of women with SCAD were identified. Mean age was not different between SCAD and non-SCAD women (51±11 and 51±10 years, respectively). The SCAD group had lower rates of ST elevation myocardial infarction, lower rises in serum creatine kinase (CK) and troponin levels, lower rates of diabetes and smoking, and far less placement of stents during the procedure than the control group. The rate of additional iatrogenic dissection relating to the cardiac catheterisation procedure was 4 of 85 (4.7%) versus 0 of 85 (0%), p=0.04 in SCAD and control groups, respectively, despite a much lower rate of percutaneous coronary intervention in the SCAD group. No common factors could be identified regarding particular equipment or procedural factors associated with iatrogenic dissection. CONCLUSION: The rate of iatrogenic dissection in women with SCAD during cardiac catheterisation is confirmed to be high and significantly higher than a contemporaneous age-matched group of women without SCAD. This observation likely indicates generalised coronary fragility in this disease, and emphasises the importance of the utmost care in the engagement, injection and intervention involving the coronary arteries in this disease. Development of a non-invasive coronary imaging modality or biomarker able to diagnose SCAD non-invasively would be a great advance in the care of patients with this condition, because it would avoid the need for invasive coronary angiography for diagnosis.

CT-Derived Fractional Flow Reserve (CT-FFR) in the Evaluation of Coronary Artery Disease.

Fractional flow reserve derived from coronary computed tomography enables anatomical and haemodynamic assessment of coronary artery disease in a single non-invasive test. Its diagnostic performance has been established against invasive fractional flow reserve in multi-centre trials, and a growing body of evidence has demonstrated its utility in predicting clinical outcomes. The purpose of this article is to describe the physiological principles, review its diagnostic performance, and describe the role of this technology in a real world clinical application.

Prognostic Value and Risk Continuum of Noninvasive Fractional Flow Reserve Derived from Coronary CT Angiography.

Background Coronary CT angiography with noninvasive fractional flow reserve (FFR) predicts lesion-specific ischemia when compared with invasive FFR. The longer term prognostic value of CT-derived FFR (FFRCT) is unknown. Purpose To determine the prognostic value of FFRCT when compared with coronary CT angiography and describe the relationship of the numeric value of FFRCT with outcomes. Materials and Methods This prospective subanalysis of the NXT study (Clinicaltrials.gov: NCT01757678) evaluated participants suspected of having stable coronary artery disease who were referred for invasive angiography and who underwent FFR, coronary CT angiography, and FFRCT. The incidence of the composite primary end point of death, myocardial infarction, and any revascularization and the composite secondary end point of major adverse cardiac events (MACE: cardiac death, myocardial infarction, unplanned revascularization) were compared for an FFRCT of 0.8 or less versus stenosis of 50% or greater on coronary CT angiograms, with treating physicians blinded to the FFRCT result. Results Long-term outcomes were obtained in 206 individuals (age, 64 years ± 9.5), including 64% men. At median follow-up of 4.7 years, there were no cardiac deaths or myocardial infarctions in participants with normal FFRCT. The incidence of the primary end point was more frequent in participants with positive FFRCT compared with clinically significant stenosis at coronary CT angiography (73.4% [80 of 109] vs 48.7% [91 of 187], respectively; P < .001), with the majority of outcomes being planned revascularization. Corresponding hazard ratios (HRs) were 9.2 (95% confidence interval [CI]: 5.1, 17; P < .001) for FFRCT and 5.9 (95% CI: 1.5, 24; P = .01) for coronary CT angiography. FFRCT was a superior predictor compared with coronary CT angiography for primary end point (C-index FFRCT, 0.76 vs coronary CT angiography, 0.54; P < .001) and MACE (FFRCT, 0.71 vs coronary CT angiography, 0.52; P = .001). Frequency of MACE was higher in participants with positive FFRCT compared with coronary CT angiography (15.6% [17 of 109] vs 10.2% [19 of 187], respectively; P = .02), driven by unplanned revascularization. MACE HR was 5.5 (95% CI: 1.6, 19; P = .006) for FFRCT and 2.0 (95% CI: 0.3, 14; P = .46) for coronary CT angiography. Each 0.05-unit FFRCT reduction was independently associated with greater incidence of primary end point (HR, 1.7; 95% CI: 1.4, 1.9; P < .001) and MACE (HR, 1.4; 95% CI: 1.1, 1.8; P < .001). Conclusion In stable patients referred for invasive angiography, a CT-derived fractional flow reserve (FFRCT) value of 0.8 or less was a predictor of long-term outcomes driven by planned and unplanned revascularization and was superior to clinically significant stenosis on coronary CT angiograms. Additionally, the numeric value of FFRCT was an independent predictor of outcomes. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Dennie and Rubens in this issue.

The Role of Fractional Flow Reserve and Instantaneous Wave-Free Ratio Measurements in Patients with Acute Coronary Syndrome.

PURPOSE OF REVIEW: The role of fractional flow reserve to guide revascularization in patients with stable angina is well established. The instantaneous wave-free ratio (iFR) is an emerging adenosine-free resting index that is non-inferior to FFR and has potential to streamline the functional evaluation of coronary artery disease. The feasibility and utility of intracoronary physiology in patients with acute coronary syndrome (ACS) is unclear. This review will discuss the physiological principles and validity of using FFR and iFR in patients presenting with ACS. We will also provide an overview of the available evidence for their role in guiding revascularization in this patient group. RECENT FINDINGS: The use of intracoronary physiology in culprit lesions of patients presenting with STEMI is not recommended and its accuracy is uncertain in patients with NSTEMI. In contrast, the physiological assessment of non-culprit vessels with FFR and IFR is a reliable measure of lesion-specific ischemia. Recent studies have demonstrated that FFR-guided revascularization of non-culprit lesions improves clinical outcomes although the role of iFR in this patient cohort is unknown. Physiology-guided revascularization of non-culprit ACS lesions improves clinical outcomes. Future studies investigating the complementary role of plaque morphology, biomechanics, and systemic inflammation may provide clinicians with a more comprehensive framework to guide treatment decisions.

Threading the Eye of the Needle: A Challenging Case of Iatrogenic Spiral Coronary Artery Dissection.

Catheter induced coronary dissection is an uncommon but potentially catastrophic complication of coronary angiography. We report a case of a 48-year-old female with normal coronary arteries on angiography complicated by extensive catheter induced spiral dissection. Wiring into the true lumen was a formidable challenge as a consequence of the large false lumen obliterating the true lumen. We present management strategies and in particular, highlight the important role of intravascular ultrasound (IVUS) imaging.

A Practical Guide for Fractional Flow Reserve Guided Revascularisation.

The presence and extent of myocardial ischaemia is a major determinant of prognosis and benefit from revascularisation in patients with stable coronary artery disease. Fractional Flow Reserve (FFR) is accepted as the reference standard for invasive assessment of ischaemia. Its ability to detect lesion specific ischaemia makes it a useful test in a wide range of patient and lesion subsets, with FFR guided intervention improving clinical outcomes and reducing health care costs compared to assessment with coronary angiography alone. This article will review the basic principles in FFR, practical tips in FFR guided revascularisation and the role of emerging non-hyperaemic indices of ischaemia.

Kounis syndrome with Samter-Beer triad treated with intracoronary adrenaline.

Kounis syndrome is a well-described clinical condition characterized by the simultaneous occurrence of chest pain and an allergic reaction accompanied by clinical and laboratory findings of angina caused by inflammatory mediators released during an allergic insult. We present the case of a 50-year-old male with the Samter-Beer triad of asthma, nasal polyps, and salicylate intolerance with an ST elevation myocardial infarction complicated with cardiac arrest due to multi-vessel coronary artery spasm secondary to aspirin anaphylaxis. Adrenaline is recommended during anaphylaxis but is controversial in Kounis syndrome as it may worsen coronary spasm. We report the use of intracoronary adrenaline in successfully reversing coronary artery spasm in this hemodynamically unstable patient.

Aortic valve laceration following rotational atherectomy: a case report.

Background: Iatrogenic aortic valve injury during cardiovascular catheterization interventions is extremely rare. Severe aortic regurgitation that ensues can be catastrophic and the management is typically with surgical valve replacement or repair. Percutaneous management of native pure aortic regurgitation is difficult due to anatomical challenges and the limitations of current transcatheter heart valve technology to anchor in the absence of leaflet or annular calcification. Case Summary: An 82-year-old female underwent rotational atherectomy (RA) for a severely calcified stenosis of the left anterior descending artery. The patient was discharged well following placement of two drug eluting stents. She represented to hospital 7 days later with acute pulmonary oedema. Bedside transthoracic echocardiography demonstrated new, severe AR with preserved left ventricular size and function. Review of the prior percutaneous coronary intervention revealed significant trauma to the aortic valve during RA, with contrast seen refluxing into the LV during diastole, evolving throughout the procedure. Given the patient was not an operative candidate, an oversized transcatheter aortic valve was successfully implanted. In the post-operative setting, the patient suffered a stroke. Extensive hypoattenuated leaflet thickening (HALT) and thrombus was seen on dedicated 4D CT imaging. She made full neurological recovery and valve function returned to normal following a period of anticoagulation. Conclusion: Although iatrogenic aortic valve laceration is rare, this case highlights several important learning points including the importance of good guide catheter support during RA; the feasibility of Transcatheter Aortic Valve Replacement for pure native AR; and the detection and management of HALT.

Cardiac computed tomography post-transcatheter aortic valve replacement.

Transcatheter aortic valve replacement (TAVR) is performed to treat aortic stenosis and is increasingly being utilised in the low-to-intermediate-risk population. Currently, attention has shifted towards long-term outcomes, complications and lifelong maintenance of the bioprosthesis. Some patients with TAVR in-situ may develop significant coronary artery disease over time requiring invasive coronary angiography, which may be problematic with the TAVR bioprosthesis in close proximity to the coronary ostia. In addition, younger patients may require a second transcatheter heart valve (THV) to 'replace' their in-situ THV because of gradual structural valve degeneration. Implantation of a second THV carries a risk of coronary obstruction, thereby requiring comprehensive pre-procedural planning. Unlike in the pre-TAVR period, cardiac CT angiography in the post-TAVR period is not well established. However, post-TAVR cardiac CT is being increasingly utilised to evaluate mechanisms for structural valve degeneration and complications, including leaflet thrombosis. Post-TAVR CT is also expected to have a significant role in risk-stratifying and planning future invasive procedures including coronary angiography and valve-in-valve interventions. Overall, there is emerging evidence for post-TAVR CT to be eventually incorporated into long-term TAVR monitoring and lifelong planning.

Evaluation of stable chest pain following emergency department presentation: Impact of first-line cardiac computed tomography diagnostic strategy in an Australian setting.

OBJECTIVE: International guidelines provide increasing support for computed tomography coronary angiography (CTCA) in investigating chest pain. A pathway utilising CTCA first-line for outpatient stable chest pain evaluation was implemented in an Australian ED. METHODS: In pre-post design, the impact of the pathway was prospectively assessed over 6 months (August 2021 to January 2022) and compared with a 6-month pre-implementation group (February 2021 to July 2021). CTCA was recommended first-line in suspected stable cardiac chest pain, followed by chest pain clinic review. Predefined criteria were provided recommending functional testing in select patients. The impact of CTCA versus functional testing was evaluated. Data were obtained from digital medical records. RESULTS: Three hundred and fifteen patients were included, 143 pre-implementation and 172 post-implementation. Characteristics were similar except age (pre-implementation: 58.9 ± 12.0 vs post-implementation: 62.8 ± 12.3 years, P = 0.004). Pathway-guided management resulted in higher first-line CTCA (73.3% vs 46.2%, P < 0.001), lower functional testing (30.2% vs 56.6%, P < 0.001) and lower proportion undergoing two non-invasive tests (4.7% vs 10.5%, P = 0.047), without increasing investigation costs or invasive coronary angiography (ICA) (pre-implementation: 13.3% vs post-implementation: 9.3%, P = 0.263). In patients undergoing CTCA, 40.7% had normal coronaries and 36.2% minimal/mild disease, with no difference in disease burden post-implementation. More medication changes occurred following CTCA compared with functional testing (aspirin: P = 0.005, statin: P < 0.001). In patients undergoing ICA, revascularisation to ICA ratio was higher following CTCA compared with functional testing (91.7% vs 18.2%, P < 0.001). No 30-day myocardial infarction or death occurred. CONCLUSIONS: The pathway increased CTCA utilisation and reduced downstream investigations. CTCA was associated with medication changes and improved ICA efficiency.