An Opportunity to Seize From Low Hanging Fruits: Capitalising on Incidentally Reported Coronary Artery Calcification.

AIM: We investigated the prevalence of incidental coronary artery calcifications (CAC) from non-electrocardiogram (ECG)-gated computed tomography (CT) chest (both contrast and non-contrast) for inpatients. We also assessed for downstream investigation and statin prescription from the inpatient teams. Incidental CAC are frequent findings on non-ECG-gated CT chest. It is associated with adverse prognosis in multiple patient cohorts. METHOD: All non-ECG-gated CT chest done as inpatients from a single centre referred from 1 January 2022 to 31 December 2022 with reported incidental CAC were reviewed for inclusion. Patients who had a history of known coronary artery disease, history of coronary stent or bypass, and presence of cardiac devices were excluded. RESULTS: Total of 123 patients were included, making the prevalence 6.2% (123/1,980). The median age is 76 years (interquartile range 69-85) and predominantly male at 54.5%. The majority of CT chest done were contrasted scans (91.1%). Only 26.8% of CAC were reported on severity with visual quantification, with 7.3% each reported for both moderate and severe CAC. Only 2.4% of CAC were reported in the conclusion of the CT report. Most of these patients were asymptomatic (34.1%). A total of 20.3% of patients had further tests done. Inpatient hospital mortality was 8.1%. About 23.6% and 34.1% of patients were on aspirin and statin therapy respectively at baseline. There was only 1 patient (1.2%) who was prescribed with new statin therapy on discharge. CONCLUSION: Incidental CAC is prevalent in inpatient settings and remains under-recognised by ordering clinicians, with low prescription rate of statin therapy. Practice-changing measures to standardise reporting of incidental CAC is needed to identify patients with subclinical coronary disease and initiate preventive interventions.

Review article: Accuracy of emergency physician performed point-of-care ultrasound of the thoracic aorta: A systematic review and narrative synthesis of the literature.

Point-of-care ultrasound (POCUS) is becoming ubiquitous in emergency medicine. POCUS for abdominal aortic aneurysm is well established in practice. The thoracic aorta can also be assessed by POCUS for dissection and aneurysm and transthoracic echocardiography is endorsed by international guidelines as an initial test for thoracic aortic pathologies. A systematic search of Ovid Medline, PubMed, EMBASE, SCOPUS and Web of Science from January 2000 to August 2022 identified four studies evaluating diagnostic accuracy of emergency physician POCUS for thoracic aortic dissection (TAD) and five studies for thoracic aortic aneurysm (TAA). Study designs were heterogeneous including differing diagnostic criteria for aortic pathology. Convenience recruitment was frequent in prospective studies. Sensitivity and specificity ranges for studies of TAD were 41-91% and 94-100%, respectively when an intimal flap was seen. Sensitivity and specificity ranges for studies of thoracic aorta dilation >40 mm were 50-100% and 93-100%, respectively; for >45 mm ranges were 64-65% and 95-99%. Literature review identified that POCUS is specific for TAD and TAA. POCUS reduces the time to diagnosis of thoracic aortic pathology; however, it remains insensitive and cannot be recommended as a stand-alone rule-out test. We suggest that detection of thoracic aorta dilation >40 mm by POCUS at any site increases the suspicion of serious aortic pathology. Studies incorporating algorithmic use of POCUS, Aortic Dissection Detection Risk Score and D-dimer as decision tools are promising and may improve current ED practices. Further research is warranted in this rapidly evolving field.

Opportunities and Challenges of Computed Tomography Coronary Angiography in the Investigation of Chest Pain in the Emergency Department-A Narrative Review.

Chest pain is one of the most common presentations to emergency departments. However, only 5.1% will be diagnosed with an acute coronary syndrome, representing considerable time and expense in the diagnosis and investigation of the patients eventually found not to be suffering from an acute coronary syndrome. PubMed and Medline databases were searched with variations of the terms "chest pain", "emergency department", "computed tomography coronary angiography". After review, 52 articles were included. Computed tomography coronary angiography (CTCA) is a class I endorsement for investigating chest pain in major international societal guidelines. CTCA offers excellent sensitivity and negative predictive value in identifying patients with coronary disease, with prognostic data impacting patient management. If CTCA is to be applied to all comers, it is pertinent to discuss the advantages and potential pitfalls if use in the Australian system is to be increased.

MINOCA: under recognized and affecting predominantly female patients-an Australian experience.

BACKGROUND: Myocardial infarction with nonobstructive coronary arteries (MINOCA) is now being recognized as an important clinical entity with prognostic implications. There are limited data in relation to MINOCA in our local Australian settings. AIM: We investigated the prevalence, clinical characteristics, major adverse cardiovascular events (MACE), and 1-year mortality of patients with MINOCA at Peninsula Health. METHOD: A single-center retrospective study of all adult patients aged ≥ 18 years who underwent invasive angiography from January 2018 to June 2020 was identified from medical records. We included patients who met the definition of MINOCA as per the 2019 AHA Statement. A simple descriptive statistical analysis was performed. RESULTS: The prevalence of MINOCA at Peninsula Health was 10.9% (131/1199) with a median age of 62 (IQR 53-74). Female patients were predominant, comprising 64% (84/131) of these patients. Chest pain was the most common symptom in 92.3% (121/131) and 58.8% (77/131) had ECG changes. A total of 81% (106/131) had a normal left ventricular systolic function and 47% of patients (66/139) had no luminal disease on invasive angiography. A total of 15.9% (23/144) of patients with an initial working diagnosis of MINOCA were referred for CMR on discharge. MACE was 5.2% (6/115) over a median follow-up of 23 months. The all-cause mortality rate at 1 year was 0.7% (1/131). CONCLUSION: The clinical prevalence rate of MINOCA at Peninsula Health is 10.9% with a MACE of 5.2%. MINOCA is recognized and the low rate of additional testing could be improved given the female predominance and prognostic implications.

Discrepancies in post-ST-elevation myocardial infarction care in women compared with men: evaluating for implicit bias-a single-centre study.

BACKGROUND: Recent research has demonstrated discrepancies in care post-ST-elevation myocardial infarction (STEMI), showing that women often have delays in time to percutaneous coronary intervention (PCI) and are less often prescribed evidence-based medications for secondary prevention. This single-centre study evaluated gender differences in management and local prescribing patterns of STEMI patients on discharge consistent with implicit bias, benchmarked against Australian clinical guidelines. METHOD AND RESULT: A retrospective, consecutive study of 318 patients admitted with a STEMI was conducted at a large tertiary hospital from January 2018 until October 2019. Data was collected from medical records including patient demographics, door-to-balloon (DTB) time, and pharmacological management. The mean age of women with a STEMI was higher (67.90 years in women; 64.17 in men, p = 0.013). DTB times were unaffected by gender with 88% of both men and women receiving PCI in less than 90 min (1.04 95% CI (0.44-2.46). Women were less likely to be prescribed an angiotensin-converting enzyme (ACE)-inhibitor/angiotensin receptor blocker (ARB) on discharge (p = 0.003). However, all other medications prescribed were appropriate between genders based on recommended guidelines. CONCLUSIONS:  Our study identified excellent adherence with recommended guidelines, challenging recent data both internationally and from the Victorian Cardiac Outcomes Registry (VCOR). Pharmacological and revascularisation management post-STEMI for both male and female patients was equal, suggesting implicit bias is not universal and may be institutional. Health services should evaluate their practices to identify sources of implicit bias, which may influence their management of women presenting with a STEMI.

Resource implications following expansion of computed tomography coronary angiography: An Australian experience.

INTRODUCTION: To determine the downstream utilisation of Computed Tomography Coronary Angiography (CTCA) in a single Australian tertiary centre. METHODS: A single-centre retrospective study analysed 1460 patients undergoing CTCA between 1st January 2015 to 31st December 2018 at a tertiary hospital in Victoria, Australia, with a catchment area of 500,000 people. The coronary stenosis grading, plaque characteristics and coronary calcium score were identified. The downstream impact was assessed by measuring the number of stress echocardiograms, myocardial perfusion scans (MPS), invasive coronary angiograms and subsequent revascularisations. RESULTS: The number of CTCA's performed steadily increased from 59 in 2015 to 395, 461 and 545 in 2016, 2017 and 2018 respectively. Seven hundred and fifty-seven (52%) were females, and 703 (48%) males with 724 (50%) normal CTCA studies. The number of downstream stress echocardiogram performed each year was 2, 60, 46 and 16, respectively, accompanied by MPS numbers of 0, 21, 29, and 18. There were 9, 37, 57 and 64 invasive coronary angiograms with 1, 13, 19 and 22 corresponding revascularisations. Despite small increases in absolute numbers of patients presenting with chest pain (from 2678 in 2015 to 3660 in 2018), there was a significant increase in downstream further testing from 11 in 2015 to 98 in 2018. CONCLUSION: The use of CTCA expansion has resulted in an increase in downstream testing. Therefore, resource planning with regards to CTCA expansion will have to account for increased rates of functional testing, invasive angiography and revascularisation.

Site qualification and clinical interpretation standards for 99mTc-SPECT perfusion imaging in a multi-center study of MITNEC (Medical Imaging Trials Network of Canada).

BACKGROUND: Qualification and interpretation standards are essential for establishing 99mTc-SPECT MPI accuracy vs. alternative modalities. METHODS: Rest-stress 99mTc-SPECT phantom scans were acquired on 35 cameras. LV defects were quantified with summed stress (SSS) and difference scores (SDS) at 2 core labs. SDS ≥ 2 in the right coronary artery (RCA) was the qualifying standard. Twenty rest (R)-stress (S) patient images were acquired on qualified cameras and interpreted by core labs. Global scoring differences > 3 between labs or discordant clinical interpretations underwent review. Scoring, interpretation, image quality, and diagnostic parameter agreement were assessed. RESULTS: Phantom scans: visual scoring confirmed RCA-ischemia on all cameras. Regional SSS, SDS agreement was moderate to very good: ICC-r = 0.57, 0.84. Patient scans: 90% of global SSS, 85% of SDS differences were ≤ 3. Regional SSS, SDS agreement: ICC-r = 0.87, 0.86, and global abnormal (SSS ≥ 4) and ischemic (SDS ≥ 2) interpretation: ICC-r = 0.90 were excellent. Clinical interpretation agreement was 100% following review. Image quality agreement was 70%. Automated metrics also agreed: ischemic total perfusion deficit ICC-r = 0.75, reversible perfusion defect, transient ischemic dilation, and S-R LV ejection fraction ICC-r ≥ 0.90. CONCLUSION: Quantitative scoring and interpretation of scans were highly repeatable with site qualification and clinical interpretation standardization, indicating that dual-core lab interpretation is appropriate to determine 99mTc-SPECT MPI accuracy.

Single CT for attenuation correction of rest/stress cardiac SPECT perfusion imaging.

Common practice is to use separate CT scans acquired during rest and stress for attenuation correction of SPECT myocardial perfusion imaging (MPI). We evaluated using a single CT scan to correct both rest and stress SPECT scans. Studies from 154 patients were reprocessed using one CT acquired at stress to correct both rest and stress scans (1CT) and compared to correction of each scan with its own CT (2CT). Two expert readers independently read the images and determined summed stress (SSS), rest (SRS), and difference (SDS) scores. The correlation in SRS between 2CT and 1CT was r ≥ 0.88. The concordance in SDS was ≥0.84 (kappa ≥ 0.62). The mean SDS difference between 2CT and 1CT for the averaged observer was not significantly different from zero (p > 0.31). 1CT images had a small but significant increase in SRS and an increase in SDS variability. However, the mean SDS difference was similar to the mean inter-observer SDS difference for the 2CT approach (-0.08 vs -0.23, p = 0.46) and had less uncertainty (1.02 vs 2.05, p < 0.001). Thus, the differences between 1CT and 2CT are unlikely to be clinically significant, and the 1CT approach is feasible for SPECT MPI.

Appropriate Use Criteria for Cardiac Computed Tomography: Does Computed Tomography Have Incremental Value in All Appropriate Use Criteria Categories?

PURPOSE: Cardiac imaging expenditures have come under scrutiny, and a focus on appropriate use criteria (AUC) has arisen to ensure cost-effective resource utilization. Although AUC has been developed by clinical experts, it has not undergone rigorous quality assurance testing to ensure that inappropriate indications for testing yield little clinical benefit. The objective of the study was to evaluate the potential incremental prognostic value of coronary computed tomographic angiography (CCTA) in the different AUC categories. MATERIALS AND METHODS: Consecutive patients enrolled into a cardiac CT Registry were collated. Patient indications were reviewed and based on the 2010 AUC (appropriate, uncertain, and inappropriate). Patients were followed-up for death, myocardial infarction (MI), and late revascularization, with the primary composite endpoint being cardiac death, nonfatal MI, and late revascularization. The prognostic value of CCTA over clinical variables in each of the AUC categories was assessed. RESULTS: Indications for CCTA were appropriate, uncertain, and inappropriate in 1284 (66.5%), 312 (16.2%), and 334 (17.3%) patients, respectively. Rates of all-cause of death, cardiac death, nonfatal MI, and late revascularization were similar across patients with appropriate, uncertain, and inappropriate indications for CCTA. Moreover, in each AUC category, CCTA had incremental prognostic value over a routine clinical risk score (National Cholesterol Education Program) with hazard ratios of 9.98, 7.39, and 5.61. CONCLUSIONS: CCTA has incremental prognostic value in all AUC categories, even when the reason for the study was deemed "inappropriate." This suggests that CCTA may still have clinical value in "inappropriate" indications and that further quality assurance AUC studies are needed.

Appropriate Use Criteria for Cardiac Computed Tomography: Impact on Diagnostic Utility.

BACKGROUND: Appropriate Use Criteria (AUC) guidelines for cardiac computed tomography (CCT) were developed to limit testing to reasonable clinical settings. However, significant testing is still done for inappropriate indications. This study investigates the impact of AUC on evaluability of CCT to determine if inappropriate tests result in a greater proportion of nondiagnostic results. METHODS: Investigators reviewed the medical records of 2417 consecutive patients who underwent CCT at the University of Ottawa Heart Institute. We applied the 2010 AUC and classified them as appropriate, inappropriate, or uncertain. Unclassifiable tests, as well as those with uncertain appropriateness, were excluded from the final analysis. Cardiac computed tomography results were classified as diagnostic if (1) all coronary segments were visualized, evaluable, and without obstructive stenosis; or (2) obstructive coronary artery disease with greater than 50% diameter stenosis in at least 1 coronary artery. All other test results were considered nondiagnostic. RESULTS: Of the 1984 patients included in the final analysis, 1522 patients (76.7%) had indications that were appropriate, whereas the remaining 462 (23.3%) were inappropriate. Inappropriate tests resulted in a higher rate of nondiagnostic results compared with appropriate CCT (9.0% vs 6.2%, P = 0.034). Inappropriate tests also had significantly more studies with nonevaluable segments than appropriate tests (24.5% vs 16.4%, P < 0.001) and were more likely to reveal obstructive coronary disease than appropriate CCT (50.5% vs 32.7%, P < 0.001). CONCLUSIONS: Cardiac computed tomography done for inappropriate indications may be associated with lower diagnostic yield and could impact future downstream resource utilization and health care costs.

Using coronary calcification to exclude an ischemic etiology for cardiomyopathy: A validation study and systematic review.

BACKGROUND: Preliminary data suggests the absence of coronary artery calcification (CAC) excludes ischemic etiologies of cardiomyopathy. We prospectively validate and perform a systematic review to determine the utility of an Agatston score=0 to exclude the diagnosis of ischemic cardiomyopathy. METHODS AND RESULTS: Patients with newly diagnosed LV dysfunction were prospectively enrolled. Patients underwent CAC imaging and were followed until an etiologic diagnosis of cardiomyopathy was made. Eighty-two patients were enrolled in the study and underwent CAC imaging with 81.7% patients having non-ischemic cardiomyopathy. An Agatston score=0 successfully excluded an ischemic etiology for cardiomyopathy with a specificity of 100% (CI: 74.7-100%) and a positive predictive value of 100% (CI: 85.0%-100%). A systematic literature review was performed and studies were deemed suitable for inclusion if: 1) patients with CHF, cardiomyopathy or LV dysfunction were enrolled, 2) underwent CAC imaging and patients were assessed for an Agatston score=0 or the absence of CAC, and 3) the final etiologic diagnosis (ischemic or non-ischemic) was provided. Eight studies provided sufficient information to calculate operating characteristics for an Agatston score=0 and were combined with our validation cohort for a total of 754 patients. An Agatston score=0 excluded ischemic cardiomyopathy with specificity and positive predictive values of 98.4% (CI: 95.6-99.5%), and 98.3% (CI: 95.5-99.5%), respectively. CONCLUSIONS: In patients with cardiomyopathy of unknown etiology, an Agatston score=0 appears to rule out an ischemic etiology. A screening CAC may be a simple and cost-effective method of triaging patients, identifying those who do and do not need additional CAD investigations.

Canceled coronary computed tomography angiography: Downstream testing and outcomes.

BACKGROUND: Downstream resource utilization and its impact on outcomes after a canceled CCTA have not been well studied. We sought to understand downstream resource utilization and patient outcomes after canceled CCTA. METHODS AND RESULTS: Consecutive patients were prospectively enrolled into an institutional cardiac CT registry. Patients who had the CCTA study canceled because of severe coronary calcification were followed for downstream resource utilization and the composite of all-cause mortality and non-fatal myocardial infarction (MI). 463 patients had their CCTA canceled due to severe coronary calcification and follow-up was available for 453 (97.8%) patients (median follow-up=36.0months). There were a total of 62 events (41 all-cause deaths and 21 non-fatal MI) with an annualized event rate of 4%. Three hundred and twenty patients underwent downstream CAD (ICA or MPI or EST) investigations. Age, NCEP/ATP III risk, beta-blocker use, Agatston and downstream CAD testing were associated with the primary outcome. There were fewer events in those that received downstream CAD testing (30 (9.7%) versus 32 (22.4%)). The annualized event rates for those who did and did not receive downstream CAD testing were 2.8% and 6.2%, respectively. Multivariable analysis confirmed that downstream CAD testing was an independent predictor of event-free survival and that the absence of additional CAD testing was associated with worse outcome (HR: 2.58 (95% CI: 1.54-4.31)). CONCLUSIONS: Patients with canceled CCTA due to severe and/or extensive CAC have high rates of death and non-fatal MI. The use of additional CAD testing appears to be associated with improved outcomes.

Meta-analysis of admission hyperglycaemia in acute myocardial infarction patients treated with primary angioplasty: a cause or a marker of mortality?

AIMS: Admission hyperglycaemia (AH) has been associated with worse outcomes in acute myocardial infarction (AMI). In the current review, we evaluated the impact of primary angioplasty (pPCI) on mortality in AMI patients with AH. Our second aim was to evaluate if AH is a marker of baseline risk or an independent predictor of mortality. METHODS AND RESULTS: A comprehensive search of four major databases was performed. We included original research studies reporting data on mortality in AMI patients with AH (mean plasma glucose >156 mg/dL/8.7 mmol) and euglycaemia who were treated with pPCI. Of 481 citations, 12 studies were included in the analysis. Admission hyperglycaemia was associated with a higher 30-day [risk ratio (RR) 4.30, P < 0.0001] and 1- to 3-year mortality (RR 2.26, P < 0.0001). As well, AH was more prevalent in women and in patients with an increasing number of cardiac risk factors or angiographic predictors of mortality, such as previous AMI (RR 0.89, P = 0.01), multivessel coronary disease (RR 0.72, P = 0.0001), and involvement of left anterior descending artery (RR 0.92, P < 0.0001). Moreover, patients with AH had larger infarcts (higher creatine kinase-MB; P = 0.004) and more frequent ventricular arrhythmias (P = 0.002). CONCLUSION: Despite rapid revascularization and treatment of hyperglycaemia, patients with AH continue to have a higher mortality. Admission hyperglycaemia occurs more commonly in patients who have traditional predictors of worse outcomes-specifically prior infarction, anterior wall infarctions, and multivessel disease. Likely, AH is a predictor of rather than a bona fide therapeutic target in AMI.

Left atrial band: a rare congenital anomaly.

Left atrial fibromuscular band is a rare congenital cardiac anomaly. We present a patient with an incidental finding of left atrial band on an intra-operative transesophageal echocardiogram and characterize its appearance on two-dimensional and three-dimensional echocardiograms.