High-Sensitivity Cardiac Troponin T Reporting, Clinical Outcomes, and Health Care Resource Use.

Importance: Despite being recommended by clinical guidelines, substantial concerns remain regarding the use of high-sensitivity cardiac troponin assays and whether it is associated with increased resource use, myocardial infarction (MI) or myocardial injury diagnoses, and procedural rates. Objective: To characterize the association of reporting high-sensitivity cardiac troponin T (hs-cTnT) to the lowest limit of quantification vs conventional troponin reporting with clinical outcomes. Design, Setting, and Participants: This cohort study used a historically controlled baseline and follow-up design to compare clinical outcomes after changing hs-cTnT reporting to the lowest limit of quantification. All patients aged 18 years or older presenting to any public emergency department (ED) in the state of South Australia between February 1, 2020, and February 28, 2021, who had an hs-cTnT test in the 6 months before and after the change in troponin reporting practice were included. Outcomes were assessed after adjusting for patient characteristics using inverse probability treatment weighting. The data analysis was performed between May 1, 2022, and July 27, 2023. Exposure: hs-cTcnT reporting. Main Outcomes and Measures: The main outcomes were frequency of diagnosed MI, coronary angiography, percutaneous coronary intervention, and coronary artery bypass graft (CABG); hospital length of stay; and ED discharge rate as measured using time-to-event Cox regression models. The secondary outcome was the composite 12-month event rate of all-cause mortality, MI, and myocardial injury. Results: A total of 40 921 patients were included, of whom 20 206 were included in the unmasked hs-cTnT reporting group (median [IQR] age, 62.0 [46.0-77.0]; 10 120 females [50.1%]) and 20 715 were included in the conventional troponin reporting group (median [IQR] age, 63.0 [47.0-77.0] years; 10 752 males [51.9%]). Unmasked hs-cTnT reporting was associated with higher ED discharge rates (45.2% vs 39.0%; P < .001) and a shorter median hospital length of stay (7.68 [IQR, 4.32-46.80] hours vs 7.92 [IQR, 4.56-49.92] hours; P < .001). There was no difference in diagnosis of MI, coronary angiography, percutaneous coronary intervention, or coronary artery bypass graft. The composite of all-cause mortality, MI, and myocardial injury at 12 months was similar (adjusted hazard ratio, 0.95; 95% CI, 0.90-1.01; P = .09). Conclusions and Relevance: This cohort study found that unrestricted reporting of hs-cTnT results to the lowest limit of quantification was not associated with an increase in the diagnosis of MI, invasive coronary procedures, or harm at 12 months but may be associated with improved hospital resource use.

Machine-Learning for Phenotyping and Prognostication of Myocardial Infarction and Injury in Suspected Acute Coronary Syndrome.

Background: Clinical work-up for suspected acute coronary syndrome (ACS) is resource intensive. Objectives: This study aimed to develop a machine learning model for digitally phenotyping myocardial injury and infarction and predict 30-day events in suspected ACS patients. Methods: Training and testing data sets, predominantly derived from electronic health records, included suspected ACS patients presenting to 6 and 26 South Australian hospitals, respectively. All index presentations and 30-day death and myocardial infarction (MI) were adjudicated using the Fourth Universal Definition of MI. We developed 2 diagnostic prediction models which phenotype myocardial injury and infarction according to the Fourth UDMI (chronic myocardial injury vs acute myocardial injury patterns, the latter further differentiated into acute non-ischaemic myocardial injury, Types 1 and 2 MI) using eXtreme Gradient Boosting (XGB) and deep-learning (DL). We also developed an event prediction model for risk prediction of 30-day death or MI using XGB. Analyses were performed in Python 3.6. Results: The training and testing data sets had 6,722 and 8,869 participants, respectively. The diagnostic prediction XGB and deep learning models achieved an area under the curve of 99.2% ± 0.1% and 98.8% ± 0.2%, respectively, for differentiating an acute myocardial injury pattern from no injury or chronic myocardial injury pattern and achieved 95.5% ± 0.2% and 94.6% ± 0.9%, respectively, for differentiating type 1 MI from type 2 MI or acute nonischemic myocardial injury. The 30-day death/MI event prediction model achieved an area under the curve of 88.5% ± 0.5%. Conclusions: Machine learning models can digitally phenotype suspected ACS patients at index presentation and predict subsequent events within 30 days. These models require external validation in a randomized clinical trial to evaluate their impact in clinical practice.

Coronary artery bypass grafting vs. percutaneous coronary intervention in severe ischaemic cardiomyopathy: long-term survival.

BACKGROUND AND AIMS: The optimal revascularization strategy in patients with ischaemic cardiomyopathy remains unclear with no contemporary randomized trial data to guide clinical practice. This study aims to assess long-term survival in patients with severe ischaemic cardiomyopathy revascularized by either coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI). METHODS: Using the Australian and New Zealand Society of Cardiac and Thoracic Surgeons and Melbourne Interventional Group registries (from January 2005 to 2018), patients with severe ischaemic cardiomyopathy [left ventricular ejection fraction (LVEF) <35%] undergoing PCI or isolated CABG were included in the analysis. Those with ST-elevation myocardial infarction and cardiogenic shock were excluded. The primary outcome was long-term National Death Index-linked mortality up to 10 years following revascularization. Risk adjustment was performed to estimate the average treatment effect using propensity score analysis with inverse probability of treatment weighting (IPTW). RESULTS: A total of 2042 patients were included, of whom 1451 patients were treated by CABG and 591 by PCI. Inverse probability of treatment weighting-adjusted demographics, procedural indication, coronary artery disease extent, and LVEF were well balanced between the two patient groups. After risk adjustment, patients treated by CABG compared with those treated by PCI experienced reduced long-term mortality [adjusted hazard ratio 0.59, 95% confidence interval (CI) 0.45-0.79, P = .001] over a median follow-up period of 4.0 (inter-quartile range 2.2-6.8) years. There was no difference between the groups in terms of in-hospital mortality [adjusted odds ratio (aOR) 1.42, 95% CI 0.41-4.96, P = .58], but there was an increased risk of peri-procedural stroke (aOR 19.6, 95% CI 4.21-91.6, P < .001) and increased length of hospital stay (exponentiated coefficient 3.58, 95% CI 3.00-4.28, P < .001) in patients treated with CABG. CONCLUSIONS: In this multi-centre IPTW analysis, patients with severe ischaemic cardiomyopathy undergoing revascularization by CABG rather than PCI showed improved long-term survival. However, future randomized controlled trials are needed to confirm the effect of any such benefits.

Prehospital factors predicting mortality in patients with shock: state-wide linkage study.

BACKGROUND: Patients with shock treated by emergency medical services (EMS) have high morbidity and mortality. Knowledge of prehospital factors predicting outcomes in patients with shock remains limited. We aimed to describe the prehospital predictors of mortality in patients with non-traumatic shock transported to hospital by EMS. METHOD: This is a retrospective cohort study of consecutive ambulance attendances for non-traumatic shock in Victoria, Australia (January 2015-June 2019) linked with government-held administrative data (emergency, admissions and mortality records). Predictors of 30-day mortality were assessed using Cox proportional regressions. The primary outcome was 30-day all-cause mortality. RESULTS: Overall, 21 334 patients with non-traumatic shock (median age 69 years, 54.8% female) were successfully linked with state administrative records. Among this cohort, 9 149 (43%) patients died within 30-days. Compared with survivors, non-survivors had a longer median on-scene time: 60 (35-98) versus 30 (19-50), p <0.001. Non-survivors were more likely to be older (median age in years: 74 (61-84) vs 65 (47-78), p<0.001), had prehospital cardiac arrest requiring cardiopulmonary resuscitation (adjusted HR (aHR)=6.26, 95% CI 5.87, 6.69) and had prehospital intubation (aHR=1.07, CI 1.00, 1.14). Reduced 30-day mortality was associated with administration of epinephrine (aHR=0.66, CI 0.62, 0.71) and systolic blood pressures above 80 mm Hg in the prehospital setting. CONCLUSION: The 30-day mortality from non-traumatic shock is high at 43%. Independent predictors of mortality included age, prehospital cardiac arrest and endotracheal intubation. Interventions that target reversible causes of short-term mortality in patients with non-traumatic shock are a high priority.

Sex-Based Outcomes of Dual-Antiplatelet Therapy After Percutaneous Coronary Intervention: A Pairwise and Network Meta-Analysis.

BACKGROUND: Although dual antiplatelet therapy (DAPT) improves the outcomes of patients undergoing percutaneous coronary intervention (PCI), sex-specific differences in efficacy and safety of DAPT remain unresolved. We compared sex differences for DAPT outcomes and DAPT durations (1-3 months [short-term], 6 months [mid-term], and >12 months [extended] vs. 12 months). METHODS: We searched databases through 31 December 2023 for trials reporting DAPT after PCI. The endpoints were major adverse cardiovascular and cerebrovascular events (MACCE), net adverse clinical and cerebrovascular events (NACCE), and any bleeding. Extracted data were pooled in a frequentist network and pairwise, random-effects meta-analysis. RESULTS: Twenty-two trials (99,591 participants, 25.2% female) were included. Female sex was significantly associated with a higher 1-year MACCE risk (hazard ratio 1.14 [95% confidence interval 1.02-1.28]) and bleeding (1.13 [1.00-1.28]), but not NACCE (1.12 [0.96-1.31]). In sub-analyses, the association between female sex and MACCE was related to use of clopidogrel as the second antiplatelet agent (1.11 [1.03-1.20]), whereas higher bleeding events were related to newer P2Y12 inhibitors (P2Y12i) (1.58 [1.01-2.46]). For DAPT duration, short-term DAPT followed by P2Y12i monotherapy was non-inferior for MACCE in females and males (0.95 [95% CI 0.83-1.10; and 0.96 [0.80-1.16]) but tended to be superior in males for NACCE versus 12-month DAPT (0.96 [0.91-1.01]); mid-term DAPT tended to be associated with a lower bleeding risk in males (0.43 [0.17-1.09]). CONCLUSIONS: Female sex is associated with higher MACCE and bleeding when newer P2Y12i agents are used. Short-term DAPT followed by P2Y12i monotherapy is safe and effective in both sexes undergoing PCI. CLINICAL TRIALS REGISTRATION: PROSPERO ID: CRD42021278663.

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.

Navigating the Landscape of Medical Device Advisories: A Special Report From the Canadian Heart Rhythm Society Device Advisory Committee.

Cardiac implantable electronic devices (CIEDs) are often important for regulating cardiac rate and rhythm. Pacemakers and defibrillators are among the top 10 most implanted medical devices, with > 1.5 million devices implanted annually. Although millions of patients have benefited with improved quality of life and survival, CIED systems are becoming increasingly complex and do not always perform according to expectations. Advisory notices communicate important information about the safety and performance of a medical device to health care providers and patients. Medical device recalls are common, with > 35 unique device recalls in the past 5 years. From an ethical standpoint, CIED recalls highlight a range of considerations including the consent process, duty to report, how best to promote autonomous decision-making, trust in the health care system, as well as disproportionate effects of these considerations on equity-deserving groups. The purpose of the current article is to review and advise regarding the process around medical device advisory and recall, with a specific focus on clinicians caring for patients affected by these devices. We have sought the input of a lawyer, a patient advocacy group, and an ethicist to guide the clinical management of, and communications regarding, device recalls and advisories. Diligent surveillance and a clear, transparent patient consent process regarding these small but potentially serious device anomalies is paramount in ensuring patients believe they are safe and informed. Meaningful patient engagement helps to ensure optimal communication and disclosure mechanisms before implantation and throughout follow-up, accessibility of information in the initial implant and recall action process, and trust in health care systems and providers.

Clinical Effectiveness and Utilisation of Cardiac Rehabilitation After Hospital Discharge: Data Linkage Analysis of 84,064 Eligible Discharged Patients (2016-2021).

BACKGROUND: Despite the highest levels of evidence on cardiac rehabilitation (CR) effectiveness, its translation into practice is compromised by low participation. AIM: This study aimed to investigate CR utilisation and effectiveness in South Australia. METHODS: This retrospective cohort study used data linkage of clinical and administrative databases from 2016 to 2021 to assess the association between CR utilisation (no CR received, commenced without completing, or completed) and the composite primary outcome (mortality/cardiovascular re-admissions within 12 months after discharge). Cox survival models were adjusted for sociodemographic and clinical data and applied to a population balanced by inverse probability weighting. Associations with non-completion were assessed by logistic regression. RESULTS: Among 84,064 eligible participants, 74,189 did not receive CR, with 26,833 of the 84,064 (31.9%) participants referred. Of these, 9,875 (36.8%) commenced CR, and 7,681 of the 9,875 (77.8%) completed CR. Median waiting time from discharge to commencement was 40 days (interquartile range, 23-79 days). Female sex (odds ratio [OR] 1.12; 95% CI 1.01-1.24; p=0.024), depression (OR 1.17; 95% CI 1.05-1.30; p=0.002), and waiting time >28 days (OR 1.15; 95% CI 1.05-1.26; p=0.005) were associated with higher odds of non-completion, whereas enrolment in a telehealth program (OR 0.35; 95% CI 0.31-0.40; p<0.001) was associated with lower odds of non-completion. Completing CR (hazard ratio [HR] 0.62; 95% CI 0.58-0.66; p<0.001) was associated with a lower risk of 12-month mortality/cardiovascular re-admissions. Commencing without completing was also associated with decreased risk (HR 0.81; 95% CI 0.73-0.90; p<0.001), but the effect was lower than for those completing CR (p<0.001). CONCLUSIONS: Cardiac rehabilitation (CR) attendance is associated with lower all-cause mortality/cardiovascular re-admissions, with CR completion leading to additional benefits. Quality improvement initiatives should include promoting referral, women's participation, access to telehealth, and reduction of waiting times to increase completion.

Association between sodium-glucose cotransporter-2 inhibitors and arrhythmic outcomes in patients with diabetes and pre-existing atrial fibrillation.

AIMS: Prior studies suggest that sodium-glucose cotransporter-2 inhibitors (SGLT2is) may decrease the incidence of atrial fibrillation (AF). However, it is unknown whether SGLT2i can attenuate the disease course of AF among patients with pre-existing AF and Type II diabetes mellitus (DM). In this study, our objective was to examine the association between SGLT2i prescription and arrhythmic outcomes among patients with DM and pre-existing AF. METHODS AND RESULTS: We conducted a population-based cohort study of adults with DM and AF between 2014 and 2019. Using a prevalent new-user design, individuals prescribed SGLT2i were matched 1:1 to those prescribed dipeptidyl peptidase-4 inhibitors (DPP4is) based on time-conditional propensity scores. The primary endpoint was a composite of AF-related healthcare utilization (i.e. hospitalization, emergency department visits, electrical cardioversion, or catheter ablation). Secondary outcome measures included all-cause mortality, heart failure (HF) hospitalization, and ischaemic stroke or transient ischaemic attack (TIA). Cox proportional hazard models were used to examine the association of SGLT2i with the study endpoint. Among 2242 patients with DM and AF followed for an average of 3.0 years, the primary endpoint occurred in 8.7% (n = 97) of patients in the SGLT2i group vs. 10.0% (n = 112) of patients in the DPP4i group [adjusted hazard ratio 0.73 (95% confidence interval 0.55-0.96; P = 0.03)]. Sodium-glucose cotransporter-2 inhibitors were associated with significant reductions in all-cause mortality and HF hospitalization, but there was no difference in the risk of ischaemic stroke/TIA. CONCLUSION: Among patients with DM and pre-existing AF, SGLT2is are associated with decreased AF-related health resource utilization and improved arrhythmic outcomes compared with DPP4is.

Microbiology of cardiac implantable electronic device infections in Calgary, Canada.

The microbiology of cardiac implantable electronic device (CIED) infections in Calgary, Alberta was described, identifying 50 infections from 2013 to 2019. The majority were Staphylococcus aureus (40.0%). There is significant economic burden, mostly related to inpatient costs, associated with CIED infections. However, there were no significant differences in costs stratified by organism.

Catheter ablation for supraventricular tachycardia and health resource utilization and expenditures: A propensity-matched cohort study.

BACKGROUND: Few data are available regarding temporal patterns of health resource utilization (HRU) and expenditures among patients undergoing catheter ablation for paroxysmal supraventricular tachycardia (PSVT). This study aimed to describe expenditures and HRU in patients with PSVT who underwent catheter ablation compared to a matched cohort of patients on medical therapy alone. METHODS: Using a large US administrative database, we identified adult patients (age 18 to 65 years) with a new PSVT diagnosis between 2008 and 2016. Propensity-score matching was used to assemble a PSVT cohort treated with ablation or medical therapy alone (N = 2556). Longitudinal trends in HRU and expenditures in the 3-years preceding and following PSVT diagnosis were compared. RESULTS: There were no significant differences in expenditures between groups except within the first year after PSVT diagnosis: $48,004 ablation vs. $17,560 medical therapy (p < 0.001). This difference was driven by procedural expenditures, where the mean cost of catheter ablation was $32,057 ± SD 26,737. In Years 2 and 3 post-ablation, HRU and expenditures decreased to the levels associated with the medical therapy group, although fewer ablation patients required any prescription for beta-blockers, calcium channel blockers, or anti-arrhythmic drugs (32% ablation vs. 42% medical therapy group, p < 0.001). CONCLUSION: Catheter ablation reduces medication burden in PSVT, yet health resource use and expenditures were similar beyond 2 years post-ablation when compared to PSVT patients on medical therapy alone. Additional studies are required to better understand drivers of these sustained health expenditures, and barriers to achieving cost-savings for a potentially curative procedure.

Sex- and Age-Specific Differences in Risk Profiles and Early Outcomes in Adults With Acute Coronary Syndromes.

BACKGROUND: Adults <55 years of age comprise a quarter of all acute coronary syndromes (ACS) hospitalisations. There is a paucity of data characterising this group, particularly sex differences. This study aimed to compare the clinical and risk profile of patients with ACS aged <55 years with older counterparts, and measure short-term outcomes by age and sex. METHOD: The study population comprised patients with ACS enrolled in the AUS-Global Registry of Acute Coronary Events (GRACE), Cooperative National Registry of Acute Coronary Syndrome Care (CONCORDANCE) and SNAPSHOT ACS registries. We compared clinical features and combinations of major modifiable risk factors (hypertension, smoking, dyslipidaemia, and diabetes) by sex and age group (20-54, 55-74, 75-94 years). All-cause mortality and major adverse events were identified in-hospital and at 6-months. RESULTS: There were 16,658 patients included (22.3% aged 20-54 years). Among them, 20-54 year olds had the highest proportion of ST-elevation myocardial infarction compared with sex-matched older age groups. Half of 20-54 year olds were current smokers, compared with a quarter of 55-74 year olds, and had the highest prevalence of no major modifiable risk factors (14.2% women, 12.7% men) and of single risk factors (27.6% women, 29.0% men), driven by smoking. Conversely, this age group had the highest proportion of all four modifiable risk factors (6.6% women, 4.7% men). Mortality at 6 months in 20-54 year olds was similar between men (2.3%) and women (1.7%), although lower than in older age groups. CONCLUSIONS: Younger adults with ACS are more likely to have either no risk factor, a single risk factor, or all four modifiable risk factors, than older patients. Targeted risk factor prevention and management is warranted in this age group.

Could Computed Tomography Coronary Angiography Replace Invasive Coronary Angiography as a First-Line Diagnostic Investigation in Suspected Acute Coronary Syndromes? A Decision-Analytic Model.

BACKGROUND: The implementation of high-sensitivity cardiac troponin (hs-cTn) assays into clinical practice has resulted in the identification of a novel cohort of patients with modestly increased troponin concentrations. Subsequent increases in rates of coronary angiography have been observed, without significant increases in rates of coronary revascularisation. Computed tomography coronary angiography (CTCA) is a non-invasive investigation that offers the opportunity to decouple investigation from the impetus to revascularise, and may provide an alternative, more risk-appropriate initial investigative strategy for the cohort with low to moderate hs-cTn increases. This analysis seeks to define the threshold of pre-test probability of coronary revascularisation in patients with suspected acute coronary syndrome at which a strategy of initial CTCA is safe and a more cost-effective approach than standard invasive coronary angiography (ICA). METHODS: A cost-benefit evaluation was conducted using a decision-analytic model. The primary outcome measure was the incremental cost-effectiveness ratio (ICER) of CTCA in comparison with ICA as an initial diagnostic investigation for patients with hs-cTnT levels between 5 and 100 ng/L. Secondary outcome measures of costs, patient outcomes, and quality-adjusted life years were analysed. RESULTS: Median base case ICER over 1,000 trials was $17,163 AUD but demonstrated large variability. Sensitivity analysis demonstrated that CTCA was cost-effective until the probability of requiring revascularisation was ∼60%, beyond which point CTCA was associated with higher costs and poorer outcomes than ICA. CONCLUSIONS: Computed tomography coronary angiography may be a cost-effective first-line investigation for patients with moderate hs-cTnT rises until/up to a 60% pre-test probability for receiving coronary revascularisation. To objectively assess the optimal circumstances of cost-effectiveness, prospective evaluation incorporating the estimated probability of revascularisation will be required.

Economic Analysis of AbClo, a Novel Abdominal Fascia Closure Device, for Patients With an Open Abdomen Following Trauma or Acute Abdominal Surgery.

BACKGROUND: Open Abdomen (OA) cases represent a significant surgical and resource challenge. AbClo is a novel non-invasive abdominal fascial closure device that engages lateral components of the abdominal wall muscles to support gradual approximation of the fascia and reduce the fascial gap. The study objective was to assess the economic implications of AbClo compared to negative pressure wound therapy (NPWT) alone on OA management. METHODS: We conducted a cost-minimization analysis using a decision tree comparing the use of the AbClo device to NPWT alone among patients with midline laparotomy for trauma or acute abdominal surgery who were ineligible for primary fascial closure. The time horizon was limited to the length of the inpatient hospital stay, and costs were considered from the perspective of the US Medicare payer. Clinical effectiveness data for AbClo was obtained from a randomized clinical trial. Cost data was obtained from the published literature. Probabilistic and deterministic sensitivity analyses were performed. The primary outcome was incremental cost. RESULTS: The mean cumulative costs per patient were $76 582 for those treated with NPWT alone and $70,582 for those in the group treated with the AbClo device. Compared to NPWT alone, AbClo was associated with lower incremental costs of -$6012 (95% CI -$19 449 to +$1996). The probability that AbClo was cost-savings compared to NPWT alone was 94%. CONCLUSIONS: The use of AbClo is an economically attractive strategy for management of OA in in patients with midline laparotomy for trauma or acute abdominal surgery who were ineligible for primary fascial closure.