High-Sensitivity Troponin I after Cardiac Surgery and 30-Day Mortality.

BACKGROUND: Consensus recommendations regarding the threshold levels of cardiac troponin elevations for the definition of perioperative myocardial infarction and clinically important periprocedural myocardial injury in patients undergoing cardiac surgery range widely (from >10 times to ≥70 times the upper reference limit for the assay). Limited evidence is available to support these recommendations. METHODS: We undertook an international prospective cohort study involving patients 18 years of age or older who underwent cardiac surgery. High-sensitivity cardiac troponin I measurements (upper reference limit, 26 ng per liter) were obtained 3 to 12 hours after surgery and on days 1, 2, and 3 after surgery. We performed Cox analyses using a regression spline that explored the relationship between peak troponin measurements and 30-day mortality, adjusting for scores on the European System for Cardiac Operative Risk Evaluation II (which estimates the risk of death after cardiac surgery on the basis of 18 variables, including age and sex). RESULTS: Of 13,862 patients included in the study, 296 (2.1%) died within 30 days after surgery. Among patients who underwent isolated coronary-artery bypass grafting or aortic-valve replacement or repair, the threshold troponin level, measured within 1 day after surgery, that was associated with an adjusted hazard ratio of more than 1.00 for death within 30 days was 5670 ng per liter (95% confidence interval [CI], 1045 to 8260), a level 218 times the upper reference limit. Among patients who underwent other cardiac surgery, the corresponding threshold troponin level was 12,981 ng per liter (95% CI, 2673 to 16,591), a level 499 times the upper reference limit. CONCLUSIONS: The levels of high-sensitivity troponin I after cardiac surgery that were associated with an increased risk of death within 30 days were substantially higher than levels currently recommended to define clinically important periprocedural myocardial injury. (Funded by the Canadian Institutes of Health Research and others; VISION Cardiac Surgery ClinicalTrials.gov number, NCT01842568.).

Rationale and design of the early valve replacement in severe asymptomatic aortic stenosis trial.

BACKGROUND: Aortic valve replacement in asymptomatic severe aortic stenosis is controversial. The Early valve replacement in severe ASYmptomatic Aortic Stenosis (EASY-AS) trial aims to determine whether early aortic valve replacement improves clinical outcomes, quality of life and cost-effectiveness compared to a guideline recommended strategy of 'watchful waiting'. METHODS: In a pragmatic international, open parallel group randomized controlled trial (NCT04204915), 2844 patients with severe aortic stenosis will be randomized 1:1 to either a strategy of early (surgical or transcatheter) aortic valve replacement or aortic valve replacement only if symptoms or impaired left ventricular function develop, or other cardiac surgery becomes nessessary. Exclusion criteria include other severe valvular disease, planned cardiac surgery, ejection fraction <50%, previous aortic valve replacement or life expectancy <2 years. The primary outcome is a composite of cardiovascular mortality or heart failure hospitalization. The primary analysis will be undertaken when 663 primary events have accrued, providing 90% power to detect a reduction in the primary endpoint from 27.7% to 21.6% (hazard ratio 0.75). Secondary endpoints include disability-free survival, days alive and out of hospital, major adverse cardiovascular events and quality of life. RESULTS: Recruitment commenced in March 2020 and is open in the UK, Australia, New Zealand, and Serbia. Feasibility requirements were met in July 2022, and the main phase opened in October 2022, with additional international centers in set-up. CONCLUSIONS: The EASY-AS trial will establish whether a strategy of early aortic valve replacement in asymptomatic patients with severe aortic stenosis reduces cardiovascular mortality or heart failure hospitalization and improves other important outcomes.

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.

An Australian Football Themed Health Behaviour Change Intervention for Men With Cardiovascular Disease is Feasible and Acceptable: Results From a Feasibility Randomised Trial.

BACKGROUND: Physical activity (PA) and weight management are critical for cardiovascular disease (CVD) secondary prevention. However, PA adherence during or after cardiac rehabilitation is low. Here, we assess the feasibility and acceptability of the Australian football-themed Aussie Fans in Training (Aussie-FIT) program and associated trial procedures when adapted for men with CVD. METHOD: A pragmatic randomised control trial, with waitlist control arm, and follow-up measures at 3 and 6 months. Men with a CVD diagnosis and body mass index ≥25 kg/m2 were recruited from community and clinical settings, and randomised, following baseline measures of health and health behaviours. The intervention arm attended 12 face-to-face football-themed education and PA sessions. Feasibility (recruitment, retention, attendance, and adherence to trial procedures) was assessed via mixed methods. RESULTS: A total of 74% (64/86) of participants expressing interest met the eligibility criteria. Of those, 49 men (mean age=61.4, standard deviation=9.5, mean body mass index=31.3, standard deviation=4.2) were randomised. Program attendance rates (87% attended ≥80% of sessions) and retention (92%) were high. Trial retention at the primary end point (3 months) was high (86%) and at the 6-month follow-ups reduced to 67%. Program and trial procedures were acceptable, except for the request to visit a pathologist for the blood draw. CONCLUSIONS: Using a football theme and setting may be a feasible way to engage men with CVD in health behaviour change. Given the existing pilot evidence for men at risk of CVD, and that recruitment rates were under the target, trialling a program for men with or at risk of CVD is recommended.

Text Messages to Improve Medication Adherence and Secondary Prevention After Acute Coronary Syndrome: The TEXTMEDS Randomized Clinical Trial.

BACKGROUND: TEXTMEDS (Text Messages to Improve Medication Adherence and Secondary Prevention After Acute Coronary Syndrome) examined the effects of text message-delivered cardiac education and support on medication adherence after an acute coronary syndrome. METHODS: TEXTMEDS was a single-blind, multicenter, randomized controlled trial of patients after acute coronary syndrome. The control group received usual care (secondary prevention as determined by the treating clinician); the intervention group also received multiple motivational and supportive weekly text messages on medications and healthy lifestyle with the opportunity for 2-way communication (text or telephone). The primary end point of self-reported medication adherence was the percentage of patients who were adherent, defined as >80% adherence to each of up to 5 indicated cardioprotective medications, at both 6 and 12 months. RESULTS: A total of 1424 patients (mean age, 58 years [SD, 11]; 79% male) were randomized from 18 Australian public teaching hospitals. There was no significant difference in the primary end point of self-reported medication adherence between the intervention and control groups (relative risk, 0.93 [95% CI, 0.84-1.03]; P=0.15). There was no difference between intervention and control groups at 12 months in adherence to individual medications (aspirin, 96% vs 96%; ß-blocker, 84% vs 84%; angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, 77% vs 80%; statin, 95% vs 95%; second antiplatelet, 84% vs 84% [all P>0.05]), systolic blood pressure (130 vs 129 mm Hg; P=0.26), low-density lipoprotein cholesterol (2.0 vs 1.9 mmol/L; P=0.34), smoking (P=0.59), or exercising regularly (71% vs 68%; P=0.52). There were small differences in lifestyle risk factors in favor of intervention on body mass index <25 kg/m2 (21% vs 18%; P=0.01), eating ≥5 servings per day of vegetables (9% vs 5%; P=0.03), and eating ≥2 servings per day of fruit (44% vs 39%; P=0.01). CONCLUSIONS: A text message-based program had no effect on medical adherence but small effects on lifestyle risk factors. REGISTRATION: URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=364448; Unique identifier: ANZCTR ACTRN12613000793718.

Lipoprotein(a) Is Associated with Thrombus Burden in Culprit Arteries of Younger Patients with ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Lipoprotein(a) (Lp[a]) is a risk factor for cardiovascular disease. The burden of thrombus in ST-segment elevation myocardial infarction (STEMI) has implications on treatment and outcomes. However, the association between Lp(a) and atherothrombosis in STEMI remains unclear. OBJECTIVES: The aim of the study was to determine the association between Lp(a) and culprit artery thrombus burden in younger patients with STEMI. METHODS: This was a single-center study of 83 patients aged <65 years with STEMI between 2016-2018 who underwent percutaneous coronary intervention and measurement of Lp(a); those receiving thrombolytic therapy were excluded. Thrombus burden in the culprit artery was determined angiographically using the Thrombolysis In Myocardial Infarction score and classified as absent-to-small, moderate, or large. Elevated Lp(a) was defined as plasma mass concentration >30 mg/dL. Multivariate analysis was performed adjusting for cardiovascular risk factors. RESULTS: The mean age was 48.0 ± 8.4 years, and 78.3% were male. Thirteen (16%), 9 (11%), and 61 (73%) patients had small, moderate, or large thrombus burden, respectively, and 34 (41%) had elevated Lp(a). Elevated Lp(a) was associated with greater thrombus burden compared to normal Lp(a) (large burden 85% vs. 65%; p = 0.024). Elevated Lp(a) was associated with moderate or large thrombus in univariate (OR 10.70 [95% CI 1.32-86.82]; p = 0.026) and multivariate analysis (OR 10.33 [95% CI 1.19-89.52]; p = 0.034). Lp(a) was not associated with culprit artery or stenosis location according to culprit artery. CONCLUSIONS: Elevated Lp(a) is associated with greater thrombus burden in younger patients with STEMI. The finding of this observational study accords with the thrombotic and anti-fibrinolytic properties of Lp(a). A causal relationship requires verification.

Cardiovascular risk management in the peri-operative setting.

Peri-operative cardiovascular events occur in up to 3% of patients undergoing non-cardiac surgery. Accurate cardiovascular risk assessment is important in the peri-operative setting, as it allows informed and shared decisions regarding the appropriateness of proceeding with surgery, guides surgical and anaesthetic approaches, and may influence the use of preventive medications and post-operative cardiac monitoring. Quantitative risk assessment may also inform a reconsideration of choosing a more limited lower risk type of surgery, or conservative management. Pre-operative cardiovascular risk assessment starts with clinical assessment and should include an estimate of functional capacity. Specialised cardiac investigations are rarely indicated specifically to assess pre-operative cardiovascular risk. The decision regarding cardiac investigations is influenced by the nature, extent and urgency of surgery. The strategy of performing pre-operative revascularisation to improve post-operative outcomes is not evidence-based and recent international guidelines recommend against this.

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.

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.

Initial treatment with a single pill containing quadruple combination of quarter doses of blood pressure medicines versus standard dose monotherapy in patients with hypertension (QUARTET): a phase 3, randomised, double-blind, active-controlled trial.

BACKGROUND: Treatment inertia is a recognised barrier to blood pressure control, and simpler, more effective treatment strategies are needed. We hypothesised that a hypertension management strategy starting with a single pill containing ultra-low-dose quadruple combination therapy would be more effective than a strategy of starting with monotherapy. METHODS: QUARTET was a multicentre, double-blind, parallel-group, randomised, phase 3 trial among Australian adults (≥18 years) with hypertension, who were untreated or receiving monotherapy. Participants were randomly assigned to either treatment, that started with the quadpill (containing irbesartan at 37·5 mg, amlodipine at 1·25 mg, indapamide at 0·625 mg, and bisoprolol at 2·5 mg) or an indistinguishable monotherapy control (irbesartan 150 mg). If blood pressure was not at target, additional medications could be added in both groups, starting with amlodipine at 5 mg. Participants were randomly assigned using an online central randomisation service. There was a 1:1 allocation, stratified by site. Allocation was masked to all participants and study team members (including investigators and those assessing outcomes) except the manufacturer of the investigational product and one unmasked statistician. The primary outcome was difference in unattended office systolic blood pressure at 12 weeks. Secondary outcomes included blood pressure control (standard office blood pressure <140/90 mm Hg), safety, and tolerability. A subgroup continued randomly assigned allocation to 12 months to assess long-term effects. Analyses were per intention to treat. This trial was prospectively registered with the Australian New Zealand Clinical Trials Registry, ACTRN12616001144404, and is now complete. FINDINGS: From June 8, 2017, to Aug 31, 2020, 591 participants were recruited, with 743 assessed for eligibility, 152 ineligible or declined, 300 participants randomly assigned to intervention of initial quadpill treatment, and 291 to control of initial standard dose monotherapy treatment. The mean age of the 591 participants was 59 years (SD 12); 356 (60%) were male and 235 (40%) were female; 483 (82%) were White, 70 (12%) were Asian, and 38 (6%) reported as other ethnicity; and baseline mean unattended office blood pressure was 141 mm Hg (SD 13)/85 mm Hg (SD 10). By 12 weeks, 44 (15%) of 300 participants had additional blood pressure medications in the intervention group compared with 115 (40%) of 291 participants in the control group. Systolic blood pressure was lower by 6·9 mm Hg (95% CI 4·9-8·9; p<0·0001) and blood pressure control rates were higher in the intervention group (76%) versus control group (58%; relative risk [RR] 1·30, 95% CI 1·15-1·47; p<0·0001). There was no difference in adverse event-related treatment withdrawals at 12 weeks (intervention 4·0% vs control 2·4%; p=0·27). Among the 417 patients who continued, uptitration occurred more frequently among control participants than intervention participants (p<0·0001). However, at 52 weeks mean unattended systolic blood pressure remained lower by 7·7 mm Hg (95% CI 5·2-10·3) and blood pressure control rates higher in the intervention group (81%) versus control group (62%; RR 1·32, 95% CI 1·16-1·50). In all randomly assigned participants up to 12 weeks, there were seven (3%) serious adverse events in the intervention group and three (1%) serious adverse events in the control group. INTERPRETATION: A strategy with early treatment of a fixed-dose quadruple quarter-dose combination achieved and maintained greater blood pressure lowering compared with the common strategy of starting monotherapy. This trial demonstrated the efficacy, tolerability, and simplicity of a quadpill-based strategy. FUNDING: National Health and Medical Research Council, Australia.

Determinants of tobacco smoking abstinence one year after major noncardiac surgery: a secondary analysis of the VISION study.

BACKGROUND: Tobacco smoking is a leading preventable cause of death and increases perioperative risk. Determinants of smoking abstinence after noncardiac surgery and the association between smoking and 1-yr vascular outcomes are not fully elucidated. METHODS: We did a prospective cohort study of 40 004 patients, aged ≥45 yr, enrolled between August 2007 and November 2013, and followed for 1 yr after surgery. Patients were categorised as never smokers, ex-smokers (quit >4 weeks preoperatively), and current smokers (smoking ≤4 weeks preoperatively). Primary outcome was abstinence at 1 yr. Secondary outcome was a composite of all-cause death, non-fatal myocardial infarction, and non-fatal stroke at 1 yr. RESULTS: Of 4658 current smokers, 1838 (39.5%) were abstinent 1 yr after surgery. Median (inter-quartile range) time to resumption was 7 (3-23) days post-surgery. Perioperatively, 7.2% of current smokers obtained smoking cessation pharmacotherapy. Older age (adjusted risk ratio [aRR] 1.21; 95% confidence interval [CI]: 1.12-1.32); having recent coronary artery disease (aRR 1.41; 95% CI: 1.29-1.55); cancer (aRR 1.37; 95% CI: 1.18-1.59); and undergoing major vascular (aRR 1.20; 95% CI: 1.02-1.41), urgent/emergent (aRR 1.14; 95% CI: 1.05-1.23), or thoracic (aRR 1.41; 95% CI: 1.26-1.56) surgeries increased abstinence. One-year abstinence was less likely when patients stopped smoking 0-1 day (aRR 0.53; 95% CI: 0.43-0.66) and 2-14 days (aRR 0.76; 95% CI: 0.71-0.82) before surgery compared with >14 days before surgery. Current smokers (adjusted hazard ratio [aHR] 1.14; 95% CI: 1.01-1.29) and ex-smokers (aHR 1.11; 95% CI: 1.03-1.21) had higher risk of the 1-yr vascular outcome compared with never smokers. CONCLUSIONS: Long-term tobacco abstinence is more likely after major surgery in those with serious medical comorbidities. Interventions to prevent smoking resumption after surgery remain a priority. Clinical trial registration NCT00512109.

Long-Term Echocardiographic Follow-Up After Transcatheter Aortic Valve Implantation to Assess Structural Valve Deterioration and Bioprosthetic Valve Failure.

BACKGROUND: Indications for transcatheter aortic valve implantation (TAVI) in aortic stenosis are expanding and the life expectancy of patients following TAVI is increasing. Determining the long-term durability of TAVI valves is therefore important. Rates of long-term (≥5 years) structural valve deterioration (SVD) vary widely and there are currently no comparable data from Australia. The aim herein was to determine the incidence of haemodynamic SVD and bioprosthetic valve failure (BVF) using recently standardised definitions in a Western Australian cohort after at least 5 years. METHODS: This is a retrospective cohort study of consecutive patients undergoing TAVI at Royal Perth Hospital between January 2009 and January 2015. Of 211 patients, 55 survived ≥5 years and had echocardiographic data available for review. Median time to the echocardiogram was 5.9 years (max 7.8 years); 49% male, mean age 83 years. RESULTS: Of the 55 survivors who had echocardiograms available ≥5 years after TAVI, four (9%) had moderate haemodynamic SVD and one (2%) had severe SVD and BVF. CONCLUSIONS: Our results suggest excellent long-term durability of contemporary TAVI valves in an Australian cohort with very low incidence of SVD and BVF. These findings add confidence to the expanding applications of TAVI valves.

Ultra-low-dose quadruple combination blood pressure-lowering therapy in patients with hypertension: The QUARTET randomized controlled trial protocol.

High blood pressure is the leading cause of preventable morbidity and mortality globally. Many patients remain on single-drug treatment with poor control, although guidelines recognize that most require combination therapy for blood pressure control. Our hypothesis is that a single-pill combination of 4 blood pressure-lowering agents each at a quarter dose may provide a simple, safe, and effective blood pressure-lowering solution which may also improve long-term adherence. The Quadruple UltrA-low-dose tReaTment for hypErTension (QUARTET) double-blind, active-controlled, randomized clinical trial will examine whether ultra-low-dose quadruple combination therapy is more effective than guideline-recommended standard care in lowering blood pressure. QUARTET will enroll 650 participants with high blood pressure either on no treatment or on monotherapy. Participants will be randomized 1:1 and allocated to intervention therapy of a single pill (quadpill) containing irbesartan 37.5 mg, amlodipine 1.25 mg, indapamide 0.625 mg, and bisoprolol 2.5 mg or to control therapy of a single identical-appearing pill containing irbesartan 150 mg. In both arms, step-up therapy of open-label amlodipine 5 mg will be provided if blood pressure is >140/90 at 6 weeks. The primary outcome is the difference between groups in the change from baseline in mean unattended automated office systolic blood pressure at 12-week follow-up. The primary outcome and some secondary outcomes will be assessed at 12 weeks; there is an optional 12-month extension phase to assess longer-term efficacy and tolerability. Our secondary aims are to assess if this approach is safe, has fewer adverse effects, and has better tolerability compared to standard care control. QUARTET will therefore provide evidence for the effectiveness and safety of a new paradigm in the management of high blood pressure.

Cardiac Complications in Patients Hospitalised With COVID-19 in Australia.

OBJECTIVES: Describe the incidence of cardiac complications in patients admitted to hospital with COVID-19 in Australia. DESIGN: Observational cohort study. SETTING: Twenty-one (21) Australian hospitals. PARTICIPANTS: Consecutive patients aged ≥18 years admitted to hospital with laboratory confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. MAIN OUTCOME MEASURES: Incidence of cardiac complications. RESULTS: Six-hundred-and-forty-four (644) hospitalised patients (62.5±20.1 yo, 51.1% male) with COVID-19 were enrolled in the study. Overall in-hospital mortality was 14.3%. Twenty (20) (3.6%) patients developed new atrial fibrillation or flutter during admission and 9 (1.6%) patients were diagnosed with new heart failure or cardiomyopathy. Three (3) (0.5%) patients developed high grade atrioventricular (AV) block. Two (2) (0.3%) patients were clinically diagnosed with pericarditis or myopericarditis. Among the 295 (45.8%) patients with at least one troponin measurement, 99 (33.6%) had a peak troponin above the upper limit of normal (ULN). In-hospital mortality was higher in patients with raised troponin (32.3% vs 6.1%, p<0.001). New onset atrial fibrillation or flutter (6.4% vs 1.0%, p=0.001) and troponin elevation above the ULN (50.3% vs 16.4%, p<0.001) were more common in patients 65 years and older. There was no significant difference in the rate of cardiac complications between males and females. CONCLUSIONS: Among patients with COVID-19 requiring hospitalisation in Australia, troponin elevation was common but clinical cardiac sequelae were uncommon. The incidence of atrial arrhythmias and troponin elevation was greatest in patients 65 years and older.

Integration of the Duke Activity Status Index into preoperative risk evaluation: a multicentre prospective cohort study.

BACKGROUND: The Duke Activity Status Index (DASI) questionnaire might help incorporate self-reported functional capacity into preoperative risk assessment. Nonetheless, prognostically important thresholds in DASI scores remain unclear. We conducted a nested cohort analysis of the Measurement of Exercise Tolerance before Surgery (METS) study to characterise the association of preoperative DASI scores with postoperative death or complications. METHODS: The analysis included 1546 participants (≥40 yr of age) at an elevated cardiac risk who had inpatient noncardiac surgery. The primary outcome was 30-day death or myocardial injury. The secondary outcomes were 30-day death or myocardial infarction, in-hospital moderate-to-severe complications, and 1 yr death or new disability. Multivariable logistic regression modelling was used to characterise the adjusted association of preoperative DASI scores with outcomes. RESULTS: The DASI score had non-linear associations with outcomes. Self-reported functional capacity better than a DASI score of 34 was associated with reduced odds of 30-day death or myocardial injury (odds ratio: 0.97 per 1 point increase above 34; 95% confidence interval [CI]: 0.96-0.99) and 1 yr death or new disability (odds ratio: 0.96 per 1 point increase above 34; 95% CI: 0.92-0.99). Self-reported functional capacity worse than a DASI score of 34 was associated with increased odds of 30-day death or myocardial infarction (odds ratio: 1.05 per 1 point decrease below 34; 95% CI: 1.00-1.09), and moderate-to-severe complications (odds ratio: 1.03 per 1 point decrease below 34; 95% CI: 1.01-1.05). CONCLUSIONS: A DASI score of 34 represents a threshold for identifying patients at risk for myocardial injury, myocardial infarction, moderate-to-severe complications, and new disability.

CSANZ Position Statement on the Evaluation of Patients Presenting With Suspected Acute Coronary Syndromes During the COVID-19 Pandemic.

A pandemic of Coronavirus-19 disease was declared by the World Health Organization on March 11, 2020. The pandemic is expected to place unprecedented demand on health service delivery. This position statement has been developed by the Cardiac Society of Australia and New Zealand to assist clinicians to continue to deliver rapid and safe evaluation of patients presenting with suspected acute cardiac syndrome at this time. The position statement complements, and should be read in conjunction with, the National Heart Foundation of Australia & Cardiac Society of Australia and New Zealand: Australian Clinical Guidelines for the Management of Acute Coronary Syndromes 2016: Section 2 'Assessment of Possible Cardiac Chest Pain'.

The Effect of Stent Artefact on Quantification of Plaque Features Using Optical Coherence Tomography (OCT): A Feasibility and Clinical Utility Study.

BACKGROUND: Optical coherence tomography (OCT) can detect detailed plaque features in native coronary arteries. Stent struts cause shadows that partially obscure the vessel wall, but plaque features can still be seen. We investigated the impact of stent artefact on plaque quantification and whether the plaque behind struts is associated with microvascular dysfunction. METHODS: Patients retrospectively recruited from two centres, underwent OCT pre- and post-stenting on the same vessel segment. Lipid (LA) and calcium (CA) were measured as arcs. Macrophages, microchannels and cholesterol crystals were counted. Subsequently, we determined whether stented plaque features were associated with reduced Thrombolysis in Myocardial Infarction (TIMI) flow grade in consecutive patients who underwent OCT post-stenting. RESULTS: In 52 patients the lipid arc was similar pre- vs post-stent: median (55º [13º-93º] vs. 40º [18º-87°]; difference 1º [-7º to 16º], p = NS). Pre- and post-stent lipid were strongly correlated (r = 0.92, p < 0.001). In a further 128 patients those with reduced (TIMI ≤ II) vs normal flow post percutaneous coronary intervention (PCI) showed more plaque behind struts: lipid (89º [50º-139º] vs 62º [29º-88°]; p < 0.001); and calcium (24º [6º-45º] vs 7° [0º-34º]; p = 0.031). Multivariate logistic regression analysis showed that abnormal TIMI flow post-stenting was associated with diabetes (Odds ratio [OR] 2.87, CI 1.01-8.19, p = 0.048), LA (OR 1.29, 95% CI 1.14-1.38, p < 0.001) and CA (OR 1.26, CI 1.07-1.40, p = 0.005). CONCLUSIONS: Plaque behind the struts can be accurately quantified using OCT. Furthermore, OCT plaque features in stented segments are associated with microvascular dysfunction post PCI.

Prophylactic Intra-Aortic Balloon Counterpulsation in High Risk Cardiac Surgery: The PINBALL Pilot Multicentre, Registry-Linked, Randomised, Controlled Feasibility Trial.

BACKGROUND: Prophylactic intra-aortic balloon counterpulsation (IABC) is commonly used in selected patients undergoing coronary artery bypass graft (CABG) surgery, but definitive evidence is lacking. The aim of the multicentre PINBALL Pilot randomised controlled trial (RCT) was to assess the feasibility of performing a definitive trial to address this question. METHODS: Patients listed for CABG surgery with impaired left ventricular function and at least one additional risk factor for postoperative low cardiac output syndrome were eligible for inclusion if the treating surgical team was uncertain as to the benefit of prophylactic IABC. The primary outcome of feasibility was based on exceeding a pre-specified recruitment rate, protocol compliance and follow-up. RESULTS: The recruitment rate of 0.5 participants per site per month did not meet the feasibility threshold of two participants per site per month and the study was stopped early after enrolment of 24 out of the planned sample size of 40 participants. For 20/24 (83%) participants, preoperative IABC use occurred according to study assignment. Six (6)-month follow-up was available for all enrolled participants, [IABC 1 death (8%) vs. control 1 death (9%), p = 0.95]. CONCLUSION: The PINBALL Pilot recruitment rate was insufficient to demonstrate feasibility of a multicentre RCT of prophylactic IABC in high risk patients undergoing CABG surgery.

The Low Dose Colchicine after Myocardial Infarction (LoDoCo-MI) study: A pilot randomized placebo controlled trial of colchicine following acute myocardial infarction.

Following an acute myocardial infarction (MI), patients with persistently elevated biomarkers of inflammation, in particular C-reactive protein (CRP), are at significantly increased risk of further cardiovascular events. Colchicine is a unique anti-inflammatory medication that has shown promise in reducing such events in patients with stable coronary heart disease. The current study tested the ability of low dose colchicine to reduce CRP levels at 30 days after an acute MI, a key marker of future outcome, and its safety and tolerability in this setting. METHODS: We conducted a randomized, double-blind, trial of low-dose colchicine (0.5 mg daily) or matching placebo in 237 patients admitted with an acute MI. The primary end-point was the proportion of patients with a residual high sensitivity CRP level ≥2 mg/L after 30 days of treatment, a threshold associated with a worse prognosis. RESULTS: At 30-day follow-up, 44% of patients treated with colchicine had a CRP level ≥2 mg/L compared to 50% of those randomized to placebo (P = .35) and the median CRP in patients randomized to colchicine was 1.6 mg/L (interquartile range [IQR] 0.7-3.5) compared to 2.0 mg/L (IQR 0.9-4.0) in patients randomized to placebo (P = .11). The median absolute reduction in CRP levels was -4.3 mg/L (IQR -1.1 to -14.1) among colchicine treated patients and -3.3 mg/L (IQR -0.9 to -14.4, P = .44) in placebo treated patients. The relative reduction was a fall of 78% compared to a fall of 64% (P = .09). Low dose colchicine was well tolerated and did not reduce compliance with other secondary preventative medications at 30-days. CONCLUSION: Treatment with low dose colchicine was safe and well tolerated, but was not associated with a significantly increased likelihood of achieving a CRP level <2 mg/L or lower absolute levels of CRP 30 days after an acute MI.