Management and outcomes with 5-year mortality of patients with mildly elevated high-sensitivity troponin T levels not meeting criteria for myocardial infarction

OBJECTIVES

To examine management and outcomes of patients presenting to EDs with symptoms suggestive of acute coronary syndrome, who have mild non-dynamically elevated high-sensitivity troponin T (HsTnT) levels, not meeting the fourth universal definition of myocardial infarction (MI) criteria (observation group).

METHODS

Consecutive patients presenting to the ED with symptoms suggestive of acute coronary syndrome at Liverpool Hospital, Sydney, Australia, those having ≥2 HsTnT levels after initial assessment were adjudicated according to the fourth universal definition of MI, as MI ruled-in, MI ruled-out, or myocardial injury in whom MI is neither ruled-in nor ruled-out (>1 level ≥15 ng/L, called observation group); follow-up was 5 years.

RESULTS

Of 2738 patients, 547 were in the observation group, of whom 62% were admitted to hospital, 52% to cardiac services, whereas 97% of MI ruled-in patients and 21% of MI ruled-out patients were admitted; P < 0.001. Non-invasive testing occurred in 42% of observation group patients (36% had echo-cardiography), and 16% had coronary angiography. Of observation group patients, MI rates were 1.5% during hospitalisation and 4% during the following year, similar to that in those with MI ruled-in, among those with MI ruled-out, the MI rate was 0.2%. The 1-year death rate was 13% among observation group patients and 11% MI ruled-in patients (P = 0.624), whereas at 5 years among observation group patients, type 1 MI and type 2 MI were 48%, 26% and 58%, respectively (P = 0.001).

CONCLUSION

Very few unselected consecutive patients attending ED, with minor stable HsTnT elevation, had MI, although most had chronic myocardial injury. Late mortality rates among observation group patients were higher than those with confirmed type 1 MI but lower than those with type 2 MI.

Impacts of high sensitivity troponin T reporting on care and outcomes in clinical practice: Interactions between low troponin concentrations and participant sex within two randomized clinical trials

BACKGROUND

The impacts of high sensitivity cardiac troponin (hs-cTn) reporting on downstream interventions amongst suspected acute coronary syndrome (ACS) in the emergency department (ED), especially amongst those with newly identified hs-cTn elevations and in consideration of well-established sex-related disparities, has not been critically evaluated to date. This investigation explores the impact of hs-cTnT reporting on care and outcomes, particularly by participant sex.

METHODS

Two similarly ED-based randomized controlled trials conducted between July 2011 to March 2013 (n = 1988) and August 2015 to April 2019 (n = 3378) were comparatively evaluated. Clinical outcomes were adjudicated to the Fourth Universal Definition of MI. Changes in practice were assessed at 30 days, and death or MI were explored to 12 months.

RESULTS

The HS-Troponin study demonstrated no difference in death or MI with unmasking amongst those with hs-cTnT <30 ng/L, whereas the RAPID TnT study demonstrated a significantly higher rate. In RAPID TnT, there was significant increase in death or MI associated with unmasking for females with hs-cTnT <30 ng/L (masked: 11[1.5%], unmasked: 25[3.4%],HR: 2.27,95%C.I.:1.87-2.77,P < 0.001). Less cardiac stress testing with unmasking amongst those <30 ng/L was observed in males in both studies, which was significant in RAPID TnT (masked: 92[12.0%], unmasked: 55[7.0%], P = 0.008). In RAPID TnT, significantly higher rates of angiography in males were observed with unmasking, with no such changes amongst females <30 ng/L (masked: 28[3.7%], unmasked: 51[6.5%],P = 0.01).

CONCLUSION

Compared with males, there were no evident impacts on downstream practices for females with unmasking in RAPID TnT, likely representing missed opportunities to reduce late death or MI.

STREAM-2: Half-Dose Tenecteplase or Primary Percutaneous Coronary Intervention in Older Patients With ST-Segment-Elevation Myocardial Infarction: A Randomized, Open-Label Trial

BACKGROUND

ST-segment-elevation myocardial infarction (STEMI) guidelines recommend pharmaco-invasive treatment if timely primary percutaneous coronary intervention (PCI) is unavailable. Full-dose tenecteplase is associated with an increased risk of intracranial hemorrhage in older patients. Whether pharmaco-invasive treatment with half-dose tenecteplase is effective and safe in older patients with STEMI is unknown.

METHODS

STREAM-2 (Strategic Reperfusion in Elderly Patients Early After Myocardial Infarction) was an investigator-initiated, open-label, randomized, multicenter study. Patients ≥60 years of age with ≥2 mm ST-segment elevation in 2 contiguous leads, unable to undergo primary PCI within 1 hour, were randomly assigned (2:1) to half-dose tenecteplase followed by coronary angiography and PCI (if indicated) 6 to 24 hours after randomization, or to primary PCI. Efficacy end points of primary interest were ST resolution and the 30-day composite of death, shock, heart failure, or reinfarction. Safety assessments included stroke and nonintracranial bleeding.

RESULTS

Patients were assigned to pharmaco-invasive treatment (n=401) or primary PCI (n=203). Median times from randomization to tenecteplase or sheath insertion were 10 and 81 minutes, respectively. After last angiography, 85.2% of patients undergoing pharmaco-invasive treatment and 78.4% of patients undergoing primary PCI had ≥50% resolution of ST-segment elevation; their residual median sums of ST deviations were 4.5 versus 5.5 mm, respectively. Thrombolysis In Myocardial Infarction flow grade 3 at last angiography was ≈87% in both groups. The composite clinical end point occurred in 12.8% (51/400) of patients undergoing pharmaco-invasive treatment and 13.3% (27/203) of patients undergoing primary PCI (relative risk, 0.96 [95% CI, 0.62-1.48]). Six intracranial hemorrhages occurred in the pharmaco-invasive arm (1.5%): 3 were protocol violations (excess anticoagulation in 2 and uncontrolled hypertension in 1). No intracranial bleeding occurred in the primary PCI arm. The incidence of major nonintracranial bleeding was low in both groups (<1.5%).

CONCLUSIONS

Halving the dose of tenecteplase in a pharmaco-invasive strategy in this early-presenting, older STEMI population was associated with electrocardiographic changes that were at least comparable to those after primary PCI. Similar clinical efficacy and angiographic end points occurred in both treatment groups. The risk of intracranial hemorrhage was higher with half-dose tenecteplase than with primary PCI. If timely PCI is unavailable, this pharmaco-invasive strategy is a reasonable alternative, provided that contraindications to fibrinolysis are observed and excess anticoagulation is avoided.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02777580.

Rapid access chest pain clinics in Australia and New Zealand

Chest pain is the second most common reason for adult emergency department presentations. Most patients have low or intermediate risk chest pain, which historically has led to inpatient admission for further evaluation. Rapid access chest pain clinics represent an innovative outpatient pathway for these low and intermediate risk patients, and have been shown to be safe and reduce hospital costs. Despite variations in rapid access chest pain clinic models, there are limited data to determine the most effective approach. Developing a national framework could be beneficial to provide sites with evidence, possible models, and business cases. Multicentre data analysis could enhance understanding and monitoring of the service.

Early Effects of Ticagrelor Versus Clopidogrel on Peripheral Endothelial Function After Non-ST-Elevation Acute Coronary Syndrome and Assessment of Its Relationship With Coronary Microvascular Function

Peripheral endothelial dysfunction is an independent predictor of adverse long-term prognosis after acute coronary syndrome. Data are lacking on the effects of oral P2Y12-inhibitors on peripheral endothelial function in non-ST-elevation acute coronary syndrome (NSTEACS). Furthermore, the relation between peripheral endothelial function and invasive indexes of coronary microvascular function in NSTEACS is unclear. Between March 2018 and July 2020, hospitalized patients with NSTEACS were randomized (1:1) to ticagrelor or clopidogrel. Peripheral endothelial function was assessed with brachial artery flow-mediated vasodilation (FMD). Invasive indexes of coronary microvascular function were obtained using an intracoronary pressure-temperature sensor-tipped wire. In 70 patients included, mean age was 58.6 years, 78.6% (n = 55) were male and 20% (n = 14) had diabetes mellitus. Compared with clopidogrel, ticagrelor significantly improved FMD (14.2 ± 5.4% vs 8.9 ± 5.3%, p <0.001) after a median treatment time of 41.2 hours. The FMD was significantly correlated with the index of microcirculatory resistance (IMR) measured in the infarct-related artery (r = -0.38, p = 0.001), with a stronger correlation found in those who did not have percutaneous coronary intervention (r = -0.52, p = 0.03). Using receiver operating characteristic curve analysis, an FMD of 8.2% identified an IMR of >34 as the threshold, with 77.6% sensitivity and 52.4% specificity. In patients who did not have a percutaneous coronary intervention, an FMD of 11.49% identified an IMR of >34 with 84.6% sensitivity and 80% specificity. In conclusion, ticagrelor significantly improved peripheral endothelial function compared with clopidogrel in patients with NSTEACS. There was a significant correlation between brachial artery FMD and IMR of the infarct-related artery.

Reperfusion strategy and late clinical outcomes of patients with ST-elevation myocardial infarction (STEMI) in the absence of standard modifiable risk factors (SMuRFs)

Introduction

There is growing evidence that patients presenting with STEMI in the absence of standard modifiable cardiovascular risk factors (SMuRFs; smoking, hypertension, hypercholesterolemia, diabetes) have poorer outcomes compared to those with atleast one SMuRF. It has been hypothesised that this may be in part due to decreased administration of pharmacotherapies in the post-infarct period due to perceived low risk. Long term outcomes of patients without SMuRFs based on reperfusion strategy received during the index admission have not been investigated.

Purpose

We sought to analyse late clinical outcomes of STEMI patients with and without SMuRFs based on reperfusion strategy received during the index admission.

Methods

All patients who underwent PCI between 2003 and 2014 were identified from a PCI centre STEMI database. Late clinical outcomes of patients with and without SMuRFs were analysed overall and based on reperfusion strategy [primary PCI (pPCI) vs pharmaco-invasive PCI (PI-PCI)]. Propensity matching was used to account for differences in baseline characteristics between the groups.

Results

Amongst 2,091 STEMI patients, 531 (25%) had no SMuRFs (51% pPCI, 49% PI-PCI) and 1560 (75%) had ≥1 SMuRF (52% pPCI, 48% PI-PCI). Unadjusted late mortality in SMuRF-less patients was 13.4% (18.8% pPCI, 7.7% PI-PCI) and for those with ≥1 SMuRF was 9.7% (11.0% pPCI, 8.4% PI-PCI). After propensity-matching clinical and angiographic characteristics, 5 year mortality rates were significantly higher for patients without SMuRFs compared to those with SMuRFs [HR 1.36, CI: 1.03–1.81, p=0.031]. This difference was attenuated for patients who underwent pPCI [HR 1.72, CI: 1.22–2.43, p=0.002]. Interestingly, this discrepancy was not observed amongst individuals who underwent pharmaco-invasive PCI [HR 1.13, CI: 0.53–1.48, p=0.638], as SMuRF-less patients had similar mortality rates to their counterparts. Long term rates of reinfarction, stent thrombosis and target vessel revascularisation were similar between the groups. Additionally, there was no significant difference in rates of stroke and major bleeding amongst all 4 subgroups.

Conclusion

Patients presenting with STEMI in the absence of SMuRFs have increased overall late mortality compared to those with at least one SMuRF. However, this difference was not observed in patients who underwent a pharmaco-invasive strategy, whereby patients without SMuRFs had similar outcomes to those with SMuRFs after adjusting for confounders. Our findings suggest the use of a pharmaco-invasive strategy in appropriate SMuRF-less patients presenting with STEMI.

Funding Acknowledgement

Type of funding sources: None.

Utility of prehospital electrocardiogram interpretation in ST-segment elevation myocardial infarction utilizing computer interpretation and transmission for interventional cardiologist consultation

Objectives

We examined the appropriateness of prehospital cardiac catheter laboratory activation (CCL‐A) in ST‐segment elevation myocardial infarction (STEMI) utilizing the University of Glasgow algorithm (UGA) and remote interventional cardiologist consultation.

Background

The incremental benefit of prehospital electrocardiogram (PH‐ECG) transmission on the diagnostic accuracy and appropriateness of CCL‐A has been examined in a small number of studies with conflicting results.

Methods

We identified consecutive PH‐ECG transmissions between June 2, 2010 and October 6, 2016. Blinded adjudication of ECGs, appropriateness of CCL‐A, and index diagnoses were performed using the fourth universal definition of MI. The primary outcome was the appropriate CCL‐A rate. Secondary outcomes included rates of false‐positive CCL‐A, inappropriate CCL‐A, and inappropriate CCL nonactivation.

Results

Among 1088 PH‐ECG transmissions, there were 565 (52%) CCL‐As and 523 (48%) CCL nonactivations. The appropriate CCL‐A rate was 97% (550 of 565 CCL‐As), of which 4.9% (n = 27) were false‐positive. The inappropriate CCL‐A rate was 2.7% (15 of 565 CCL‐As) and the inappropriate CCL nonactivation rate was 3.6% (19 of 523 CCL nonactivations). Reasons for appropriate CCL nonactivation (n = 504) included nondiagnostic ST‐segment elevation (n = 128, 25%), bundle branch block (n = 132, 26%), repolarization abnormality (n = 61, 12%), artefact (n = 72, 14%), no ischemic symptoms (n = 32, 6.3%), severe comorbidities (n = 26, 5.2%), transient ST‐segment elevation (n = 20, 4.0%), and others.

Conclusions

PH‐ECG interpretation utilizing UGA with interventional cardiologist consultation accurately identified STEMI with low rates of inappropriate and false‐positive CCL‐As, whereas using UGA alone would have almost doubled CCL‐As. The benefits of cardiologist consultation were identifying “masquerading” STEMI and avoiding unnecessary CCL‐As.

Late Outcomes of Patients With Prehospital ST-Segment Elevation and Appropriate Cardiac Catheterization Laboratory Nonactivation

Background Patients with suspected ST-segment-elevation myocardial infarction (STEMI) and cardiac catheterization laboratory nonactivation (CCL-NA) or cancellation have reportedly similar crude and higher adjusted risks of death compared with those with CCL activation, though reasons for these poor outcomes are not clear. We determined late clinical outcomes among patients with prehospital ECG STEMI criteria who had CCL-NA compared with those who had CCL activation. Methods and Results We identified consecutive prehospital ECG transmissions between June 2, 2010 to October 6, 2016. Diagnoses according to the Fourth Universal Definition of myocardial infarction (MI), particularly rates of myocardial injury, were adjudicated. The primary outcome was all-cause death. Secondary outcomes included cardiovascular death/MI/stroke and noncardiovascular death. To explore competing risks, cause-specific hazard ratios (HRs) were obtained. Among 1033 included ECG transmissions, there were 569 (55%) CCL activations and 464 (45%) CCL-NAs (1.8% were inappropriate CCL-NAs). In the CCL activation group, adjudicated index diagnoses included MI (n=534, 94%, of which 99.6% were STEMI and 0.4% non-STEMI), acute myocardial injury (n=15, 2.6%), and chronic myocardial injury (n=6, 1.1%). In the CCL-NA group, diagnoses included MI (n=173, 37%, of which 61% were non-STEMI and 39% STEMI), chronic myocardial injury (n=107, 23%), and acute myocardial injury (n=47, 10%). At 2 years, the risk of all-cause death was higher in patients who had CCL-NA compared with CCL activation (23% versus 7.9%, adjusted risk ratio, 1.58, 95% CI, 1.24-2.00), primarily because of an excess in noncardiovascular deaths (adjusted HR, 3.56, 95% CI, 2.07-6.13). There was no significant difference in the adjusted risk for cardiovascular death/MI/stroke between the 2 groups (HR, 1.23, 95% CI, 0.87-1.73). Conclusions CCL-NA was not primarily attributable to missed STEMI, but attributable to "masquerading" with high rates of non-STEMI and myocardial injury. These patients had worse late outcomes than patients who had CCL activation, mainly because of higher rates of noncardiovascular deaths.

Impact of Ticagrelor Versus Clopidogrel on Coronary Microvascular Function After Non-ST-Segment-Elevation Acute Coronary Syndrome

BACKGROUND

Coronary microvascular dysfunction after acute coronary syndrome is an important predictor of long-term prognosis. Data is lacking on the effects of oral P2Y₁₂-inhibitors on coronary microvascular function in non-ST-segment-elevation acute coronary syndrome. The aim of this study was to compare the acute effects of ticagrelor versus clopidogrel pretreatment on coronary microvascular function in non-ST-segment-elevation acute coronary syndrome patients.

METHODS

Hospitalized non-ST-segment-elevation acute coronary syndrome patients were randomized (1:1) to ticagrelor or clopidogrel. The index of microcirculatory resistance, coronary flow reserve, and resistive reserve ratio were obtained using an intracoronary pressure-temperature sensor-tipped wire.

RESULTS

In total, 128 patients were randomized between March 2018 and July 2020. Mean age 59.2±11.8 years, 84% were male, mean Global Registry of Acute Coronary Events score was 93.7±24.5. Intracoronary physiological measurements were obtained in 118 patients (60 ticagrelor, 58 clopidogrel). In the infarct-related artery, the ticagrelor group had lower baseline index of microcirculatory resistance (22.0 [13.0-34.9] versus 27.7 [19.3-29.8]; P=0.02) and higher baseline resistive reserve ratio (3.0 [2.3-4.4] versus 2.4 [1.7-3.4]; P=0.01) compared with the clopidogrel group. A total of 88 patients underwent percutaneous coronary intervention (PCI; 45 ticagrelor, 43 clopidogrel). The ticagrelor group had lower post-PCI index of microcirculatory resistance (22.0 [15.0-29.0] versus 27.0 [18.5-47.5]; P=0.02) and higher post-PCI resistive reserve ratio (3.0 [1.8-3.8] versus 1.8 [1.5-3.4]; P=0.006) compared with the clopidogrel group. The coronary flow reserve was not significantly different between the 2 groups at baseline or post-PCI. No between-group differences were seen in any of the indices in the non-infarct-related artery.

CONCLUSIONS

In non-ST-segment-elevation acute coronary syndrome patients, ticagrelor significantly improved coronary microvascular function before and after PCI compared with clopidogrel.

REGISTRATION

URL: https://www.anzctr.org.au; Unique identifier: ACTRN12618001610224.

Implementation of more sensitive cardiac troponin T assay in a state-wide health service

AIMS

Explore the impact of deploying high-sensitivity (hs) cardiac troponin T (cTnT) assay across a state-wide health service.

METHODS AND RESULTS

Presentations to emergency departments of six tertiary hospitals between January 2008 and August 2019 were included; standard cTnT assay was superseded by hs-cTnT in June 2011 without changing the reference range (≥30 ng/L reported as elevated), despite cTnT level of 30 ng/L being equivalent to ∼44 ng/L with hs-cTnT. Clinical outcomes were captured using state-wide linked health records. Interrupted time series analyses were used adjusted for seasonality and multiple co-morbidities using propensity score matching allowing for correlation within hospitals. In total, 614,847 presentations had ≥1 troponin measurement. Clinical ordering of troponin decreased throughout the study with no increase in elevated measurements amongst those tested with hs-cTnT. Small but statistically significant changes in index myocardial infarction (MI) diagnosis (-0.36%/year, 95%CI [confidence interval]:-0.48, -0.24,p < 0.001) and invasive coronary angiography (0.12%/year,95%CI:0, 0.24,p = 0.02) were seen, with no impact on death/MI at 30 days or 3-year survival in episodes of care (EOCs) with elevated cTnT after hs-cTnT implementation. Length of stay (LOS) was shorter among those with an elevated hs-cTnT (-4.44 h/year, 95%CI:-5.27, -3.60, p < 0.001). Non-elevated cTnT EOCs demonstrated shorter total LOS and improved 3-year survival (adjusted hazard ratio:0.90, 95%CI:0.83, 0.97,p = 0.008) although death/MI at 30 days was unchanged using hs-cTnT.

CONCLUSION

Widespread implementation of hs-cTnT without altering clinical thresholds reported to clinicians provided significantly shorter LOS without a clinically significant impact on clinical outcomes. A safer cohort with non-elevated cTnT was identified by hs-cTnT compared to the standard cTnT assay.

Cost effectiveness of a 1-hour high-sensitivity troponin-T protocol: An analysis of the RAPID-TnT trial

•

This is the first randomised evaluation of the cost-effectiveness of a 0/1-hour high-sensitivity troponin protocol and has implications on clinical practice on a health system level.

•

The results demonstrate that the 0/1-hour hs-cTnT protocol is safe and does not incur excess resource compared to the conventional 0/3-hour protocol.

•

Whilst this cost-effectiveness analysis demonstrates superior ED efficiency and equivalent safety and resource associated with the 0/1-hour hs-cTnT protocol, further refinements in subsequent management is necessary to facilitate large-scale adaptation.

Background

To understand the economic impact of an accelerated 0/1-hour high-sensitivity troponin-T (hs-cTnT) protocol.

Objective

To conduct a patient-level economic analysis of the RAPID-TnT randomised trial in patients presenting with suspected acute coronary syndrome (ACS).

Methods

An economic evaluation was conducted with 3265 patients randomised to either the 0/1-hour hs-cTnT protocol (n = 1634) or the conventional 0/3-hour standard-of-care protocol (n = 1631) with costs reported in Australian dollars. The primary clinical outcome was all-cause mortality or new/recurrent myocardial infarction.

Results

Over 12-months, mean per patient costs were numerically higher in the 0/1-hour arm compared to the conventional 0/3-hour arm (by $472.49/patient, 95% confidence interval [95 %CI]: $-1,380.15 to $2,325.13, P = 0.617) with no statistically significant difference in primary outcome (0/1-hour: 62/1634 [3.8%], 0/3-hour: 82/1631 [5.0%], HR: 1.32 [95 %CI: 0.95–1.83], P = 0.100). The mean emergency department (ED) length of stay (LOS) was significantly lower in the 0/1-hour arm (by 0.62 h/patient, 95 %CI: 0.85 to 0.39, P < 0.001), but the subsequent 12-month unplanned inpatient costs was numerically higher (by $891.22/patient, 95 %CI: $-96.07 to 1,878.50, P = 0.077). Restricting the analysis to patients with hs-cTnT concentrations ≤ 29 ng/L, mean per patient cost remained numerically higher in the 0/1-hour arm (by $152.44/patient, 95 %CI:$-1,793.11 to $2,097.99, P = 0.988), whilst the reduction in ED LOS was more pronounced (by 0.70 h/patient, 95 %CI: 0.45–0.95, P < 0.001).

Conclusions

There were no differences in resource utilization between the 0/1-hour hs-cTnT protocol versus the conventional 0/3-hour protocol for the assessment of suspected ACS, despite improved initial ED efficiency. Further refinements in strategies to improve clinical outcomes and subsequent management efficiency are needed.

Right ventricular myocardial infarction: pathophysiology, clinical implications and management

Right ventricular myocardial infarction (RVMI) and right ventricular (RV) failure are complications from an acute occlusion of a dominant right coronary artery (RCA) or left anterior descending (LAD) artery. Although some patients have good long-term RV recovery, RVMI is associated with high rates of in-hospital morbidity and mortality driven by hemodynamic compromise, cardiogenic shock, and electrical complications. As such, it is important to identify specific clinical signs and symptoms, initiate resuscitation and commence reperfusion therapy with fibrinolytic therapy or percutaneous coronary intervention. This review will discuss RVMI pathophysiology, describe the current diagnostic measures, highlight current therapies, and explore future management options.

Reperfusion After Fibrinolytic Therapy (RAFT): An open-label, multi-centre, randomised controlled trial of bivalirudin versus heparin in rescue percutaneous coronary intervention

BACKGROUND

The safety and efficacy profile of bivalirudin has not been examined in a randomised controlled trial of patients undergoing rescue PCI.

OBJECTIVES

We conducted an open-label, multi-centre, randomised controlled trial to compare bivalirudin with heparin ± glycoprotein IIb/IIIa inhibitors (GPIs) in patients undergoing rescue PCI.

METHODS

Between 2010-2015, we randomly assigned 83 patients undergoing rescue PCI to bivalirudin (n = 42) or heparin ± GPIs (n = 41). The primary safety endpoint was any ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) bleeding at 90 days. The primary efficacy endpoint was infarct size measured by peak troponin levels as a multiple of the local upper reference limit (Tn/URL). Secondary endpoints included periprocedural change in haemoglobin adjusted for red cells transfused, TIMI (Thrombolysis in Myocardial Infarction) bleeding, ST-segment recovery and infarct size determined by the Selvester QRS score.

RESULTS

The trial was terminated due to slow recruitment and futility after an interim analysis of 83 patients. The primary safety endpoint occurred in 6 (14%) patients in the bivalirudin group (4.8% GPIs) and 3 (7.3%) in the heparin ± GPIs group (54% GPIs) (risk ratio, 1.95, 95% confidence interval [CI], 0.52-7.3, P = 0.48). Infarct size was similar between the two groups (mean Tn/URL, 730 [±675] for bivalirudin, versus 984 [±1585] for heparin ± GPIs, difference, 254, 95% CI, -283-794, P = 0.86). There was a smaller decrease in the periprocedural haemoglobin level with bivalirudin than heparin ± GPIs (-7.5% [±15] versus -14% [±17], difference, -6.5%, 95% CI, -0.83-14, P = 0.0067). The rate of complete (≥70%) ST-segment recovery post-PCI was higher in patients randomised to heparin ± GPIs compared with bivalirudin.

CONCLUSIONS

Whether bivalirudin compared with heparin ± GPI reduces bleeding in rescue PCI could not be determined. Slow recruitment and futility in the context of lower-than-expected bleeding event rates led to the termination of this trial (ANZCTR.org.au, ACTRN12610000152022).

Prognostic Implications of High-Sensitivity Troponin T Levels Among Patients Attending Emergency Departments and Evaluated for an Acute Coronary Syndrome

BACKGROUND

With increasing age, patients with suspected acute coronary syndromes (ACS) and elevated high-sensitivity troponin T (HsTnT) levels, type-1 myocardial infarction (MI) is diagnosed less often, though associations among these factors, gender, and prognosis is unclear.

METHODS

Patients presenting to the emergency department (ED) with potential ACS who underwent HsTnT testing were prospectively identified and followed. Diagnoses were adjudicated according to the Fourth Universal Definition of MI as follows: type-1 MI, type-2 MI, acute myocardial injury, chronic myocardial injury, and other diagnoses. Age in years was categorized: younger (<65); elderly (65-79), and very elderly (≥80).

RESULTS

Among 2738 patients with HsTnT measurements, 1611 were suitable for adjudication (42% ages 65 years and younger). Type-2 MI and chronic myocardial injury diagnoses were more common in those ages 65 years and older, whereas younger patients had more type-1 MI diagnoses. Late mortality rates at median 41 months (interquartile range [IQR] 10-57) were 44% (223 out of 506) in those ages 80 years and older, 22% (92 out of 423) in patients 65-79 years, and 7% (46 out of 682) in those 65 years and younger, irrespective of adjudicated diagnoses, log rank P ≤ .001. On multivariable analyses, the adjusted mortality hazard ratios for increasing HsTnT levels irrespective of diagnoses were attenuated in those age 80 years and older compared to younger patients.

CONCLUSIONS

Patients ages 65 years and older constituted ~60% of ED attendances of patients with suspected ACS, and more had type 2 MI and chronic myocardial injury diagnoses compared to younger patients. The relative mortality impact of HsTnT levels was lower among elderly patients irrespective of adjudicated diagnoses.

Classification performance of clinical risk scoring in suspected acute coronary syndrome beyond a rule-out troponin profile

AIMS

High-sensitivity cardiac troponin strategies can provide risk stratification in patients with suspected acute coronary syndrome (ACS) in the emergency department (ED). This study evaluated whether clinical risk scoring improves the classification performance of a rule-out profile in suspected ACS.

METHODS AND RESULTS

Patients presenting to ED with suspected ACS as part of the RAPID-TnT trial randomized to the intervention arm were included. Results ≥5 ng/L were available for all participants in this analysis. We evaluated the Thrombolysis In Myocardial Infarction (TIMI) risk score, History ECG Age Risk factors Troponin (HEART) score, and Emergency Department Assessment of Chest pain Score (EDACS) in addition to a rule-out profile based on the 0/1-h high-sensitivity cardiac troponin T protocol (<5 ng/L or ≤12 ng/L and a change of <3 ng/L at 1-h) using test performance parameters focusing on low-risk groups to identify the primary endpoint (TIMI ≤ 1, HEART ≤ 3, EDACS < 16). Primary endpoint was a composite of type 1/2 myocardial infarction (MI) at index presentation and all-cause mortality or type 1/2 MI at 30 days. A total of 3378 participants were enrolled between August 2015 and April 2019 of which 108 were ineligible/withdrew consent (intervention arm: n = 1638). Sensitivity, specificity, negative predictive value (NPV), and area under the curve (AUC) of the rule-out profile was 94.4%, 76.8%, 99.6%, and 0.86, respectively with 72.9% identified as 'low-risk'. Adding the clinical risk scores did not improve the sensitivity, NPV, or AUC with significantly lower specificity and 'low-risk' classified participants.

CONCLUSIONS

Addition of clinical risk scores to rule-out profile did not demonstrate improved classification performance for identifying the composite of type 1/2 MI at index presentation and all-cause mortality or type 1/2 MI at 30 days.

CLINICAL TRIALS REGISTRATION

URL: https://www.anzctr.org.au. Reg. No. ACTRN12615001379505.

Late Outcomes of the RAPID-TnT Randomized Controlled Trial: 0/1-Hour High-Sensitivity Troponin T Protocol in Suspected ACS

BACKGROUND

High-sensitivity troponin assays are increasingly being adopted to expedite evaluation of patients with suspected acute coronary syndromes. Few direct comparisons have examined whether the enhanced performance of these assays at low concentrations leads to changes in care that improves longer-term outcomes. This study evaluated late outcomes of participants managed under an unmasked 0/1-hour high-sensitivity cardiac troponin T (hs-cTnT) protocol compared with a 0/3-hour masked hs-cTnT protocol.

METHODS

We conducted a multicenter prospective patient-level randomized comparison of care informed by unmasked 0/1-hour hs-cTnT protocol (reported to <5 ng/L) versus standard practice masked hs-cTnT testing (reported to ≤29 ng/L) assessed at 0/3 hours and followed participants for 12 months. Participants included were those presenting to metropolitan emergency departments with suspected acute coronary syndromes, without ECG evidence of coronary ischemia. The primary end point was time to all-cause death or myocardial infarction using Cox proportional hazards models adjusted for clustering within hospitals.

RESULTS

Between August 2015 and April 2019, we randomized 3378 participants, of whom 108 withdrew, resulting in 12-month follow-up for 3270 participants (masked: 1632; unmasked: 1638). Among these, 2993 (91.5%) had an initial troponin concentration of ≤29 ng/L. Deployment of the 0/1-hour hs-cTnT protocol was associated with reductions in functional testing. Over 12-month follow-up, there was no difference in invasive coronary angiography (0/1-hour unmasked: 232/1638 [14.2%]; 0/3-hour masked: 202/1632 [12.4%]; P=0.13), although an increase was seen among patients with hs-cTnT levels within the masked range (0/1-hour unmasked arm: 168/1507 [11.2%]; 0/3-hour masked arm: 124/1486 [8.3%]; P=0.010). By 12 months, all-cause death and myocardial infarction did not differ between study arms overall (0/1-hour: 82/1638 [5.0%] versus 0/3-hour: 62/1632 [3.8%]; hazard ratio, 1.32 [95% CI, 0.95-1.83]; P=0.10). Among participants with initial troponin T concentrations ≤29 ng/L, unmasked hs-cTnT reporting was associated with an increase in death or myocardial infarction (0/1-hour: 55/1507 [3.7%] versus 0/3-hour: 34/1486 [2.3%]; hazard ratio, 1.60 [95% CI, 1.05-2.46]; P=0.030).

CONCLUSIONS

Unmasked hs-cTnT reporting deployed within a 0/1-hour protocol did not reduce ischemic events over 12-month follow-up. Changes in practice associated with the implementation of this protocol may be associated with an increase in death and myocardial infarction among those with newly identified troponin elevations. Registration: URL: https://www.anzctr.org.au; Unique identifier: ACTRN12615001379505.

Type-II myocardial infarction and chronic myocardial injury rates, invasive management, and 4-year mortality among consecutive patients undergoing high-sensitivity troponin T testing in the emergency department

AIMS

As assessment of patients with suspected acute coronary syndromes (ACS) in emergency departments (EDs) represents a major workload because high-sensitivity troponin (HsTn) T and I levels are frequently measured, and a minority of patients have final diagnosis of myocardial infarction (MI). We determined the relative frequencies of three patients groups: Type-I MI, Type-II MI (including acute myocardial injury).

METHODS AND RESULTS

Among 2738 consecutive patients with suspected ACS presenting to ED at Liverpool Hospital, Australia, between March and June 2014. We studied the use of invasive and pharmacological therapies, and 4-year outcomes. Adjudication of MI was according to the 4th universal definition as follows: (i) Type-I MI; (ii) Type-II MI (including acute myocardial injury), and (iii) chronic myocardial injury. Of 995 patients (36%) [median age 76 years (interquartile range 65-83)] with ≥2 HsTnT measurements and one >14 ng/L, 727 (73%) had chronic myocardial injury, 171 (17%) had Type-II MI, and 97 (9.7%) had Type-I MI; respective late mortality rates to 48 months were 33%, 43%, and 14% (P < 0.001). In-hospital angiography rates were 95% for patients with Type-I MI, [62% had percutaneous coronary intervention (PCI)] 24% (7% PCI) for those with Type-II MI, and 3.4% for chronic myocardial injury. On Cox modelling for mortality relative to Type 1 MI, adjusted hazard ratios were 1.94 [95% confidence intervals (CIs) 1.06-3.57]; P = 0.032 for Type 2 MI, and for chronic myocardial injury 1.14 (95% CIs 0.64-2.02); P = 0.66.

CONCLUSION

Among unselected patients undergoing HsTnT testing in EDs, Type-II MI including acute myocardial injury was more common than Type-I MI. Chronic myocardial injury, which occurred in three of four patients. Whereas patients with Type-II MI had higher late mortality than those with Type-I MI, after multivariable analyses mortality rates were marginally different.

Troponin elevation pattern and subsequent cardiac and non-cardiac outcomes: Implementing the Fourth Universal Definition of Myocardial Infarction and high-sensitivity troponin at a population level

Background

The Fourth Universal Definition of Myocardial Infarction (MI) differentiates MI from myocardial injury. We characterised the temporal course of cardiac and non-cardiac outcomes associated with MI, acute and chronic myocardial injury.

Methods

We included all patients presenting to public emergency departments in South Australia between June 2011–Sept 2019. Episodes of care (EOCs) were classified into 5 groups based on high-sensitivity troponin-T (hs-cTnT) and diagnostic codes: 1) Acute MI [rise/fall in hs-cTnT and primary diagnosis of acute coronary syndrome], 2) Acute myocardial injury with coronary artery disease (CAD) [rise/fall in hs-cTnT and diagnosis of CAD], 3) Acute myocardial injury without CAD [rise/fall in hs-cTnT without diagnosis of CAD], 4) Chronic myocardial injury [elevated hs-cTnT without rise/fall], and 5) No myocardial injury. Multivariable flexible parametric models were used to characterize the temporal hazard of death, MI, heart failure (HF), and ventricular arrhythmia.

Results

372,310 EOCs (218,878 individuals) were included: acute MI (19,052 [5.12%]), acute myocardial injury with CAD (6,928 [1.86%]), acute myocardial injury without CAD (32,231 [8.66%]), chronic myocardial injury (55,056 [14.79%]), and no myocardial injury (259,043 [69.58%]). We observed an early hazard of MI and HF after acute MI and acute myocardial injury with CAD. In contrast, subsequent MI risk was lower and more constant in patients with acute injury without CAD or chronic injury. All patterns of myocardial injury were associated with significantly higher risk of all-cause mortality and ventricular arrhythmia.

Conclusions

Different patterns of myocardial injury were associated with divergent profiles of subsequent cardiac and non-cardiac risk. The therapeutic approach and modifiability of such excess risks require further research.

Comparing the clinical and prognostic impact of proximal versus nonproximal lesions in dominant right coronary artery ST-elevation myocardial infarction

OBJECTIVE

To evaluate the prognostic significance of culprit lesion location in dominant right coronary artery (RCA) ST-elevation myocardial infarction (STEMI).

BACKGROUND

In RCA STEMI, proximal culprit lesions have been shown to have higher rates of acute complications such as bradycardia and cardiogenic shock (CS) but data on mortality is limited.

METHODS

We retrospectively identified and analyzed data from consecutive patients with a dominant RCA STEMI who underwent either primary or rescue percutaneous coronary intervention (PCI) between January 2003 and December 2016. We compared the rates of sustained ventricular tachycardia (VT), CS, intra-aortic balloon pump (IABP), temporary cardiac pacing (TCP) and death between culprit lesions located proximal and distal to the origin of the last right ventricular (RV) marginal artery >1 mm in diameter.

RESULTS

The 939 patients were included; 599 (63.7%) had a proximal lesion and 340 (36.3%) had a nonproximal lesion. The 801 (85.3%) underwent primary PCI and 138 (14.7%) underwent rescue PCI. There was no difference in first medical contact to balloon or fibrinolysis times between the groups; p = .98 and .71. There was no significant difference in the rate of sustained VT (3.0%vs. 3.2%, p = .85) but proximal lesions were more likely to develop CS (10.9%vs. 5.8%, p = .01), require IABP (7.3%vs.2.9%, p < .01) and TCP (6.3%vs. 2.6%, p = .01). Thirty-day mortality was higher for proximal lesions (5.0%vs. 0.9%, p < .01) particularly for those with CS (35.3%vs. 10.0%, p = .05).

CONCLUSION

Culprit lesions located proximal to the origin of the last RV marginal artery had a higher rate of acute complications such as CS and mortality.

Consensus guidelines for interventional cardiology services delivery during covid-19 pandemic in Australia and new Zealand

The global coronavirus disease (COVID-19) pandemic poses an unprecedented stress on healthcare systems internationally. These Health system-wide demands call for efficient utilisation of resources at this time in a fair, consistent, ethical and efficient manner would improve our ability to treat patients. Excellent co-operation between hospital units (especially intensive care unit [ICU], emergency department [ED] and cardiology) is critical in ensuring optimal patient outcomes. The purpose of this document is to provide practical guidelines for the effective use of interventional cardiology services in Australia and New Zealand. The document will be updated regularly as new evidence and knowledge is gained with time. Goals Considerations.

Mortality at 5 Years Among Very Elderly Patients Undergoing High Sensitivity Troponin T Testing for Suspected Acute Coronary Syndromes

BACKGROUND

Patients aged ≥80 years old often present to Emergency Departments (ED) with symptoms potentially due to an acute coronary syndrome (ACS). This study aimed to evaluate associations between baseline level(s) of high sensitivity troponin T (HsTnT), adjudicated diagnoses and outcomes.

METHODS

Consecutive patients aged ≥80 years were studied, who presented to the ED at Liverpool Hospital, NSW, Australia during the 4 months period March to June 2014 (inclusive) with symptoms suggestive of an ACS, and who had at least one HsTnT assay performed. Diagnoses were based on the fourth universal definition of MI (myocardial infarction) including type-1 MI, type-2 MI, acute myocardial injury, chronic myocardial injury; the rest were termed "other diagnoses". Patients were categorised by baseline HsTnT levels 1) ≤14 ng/L, 2) 15-29 ng/L, 3) 30-49 ng/L and 4) ≥50 ng/L.

RESULTS

Of 2,773 patients screened, 545 were aged ≥80 years (median age 85 [IQR 82-88]); median follow-up was 32 months (IQR 5-56). The respective rates of adjudicated diagnoses were type-I MI 3.1%, type-2 MI 13%, acute myocardial injury 9.5%, chronic myocardial injury 56% and 18.6% had other diagnoses. Mortality rates increased, irrespective of adjudicated diagnoses with increasing HsTnT levels (ng/L): 17% (16/96) for ≤14; 35% (67/194) for 15-29; 51% (65/127) for 30-49; and 64% (82/128) for ≥50 ng/L; log rank p≤0.001. On multi-variable analyses, after adjusting for potential confounding factors including age, hypertension, chronic kidney disease (CKD) and chronic obstructive pulmonary disease (COPD), MI type was not associated with late mortality.

CONCLUSIONS

Among patients aged ≥80 years higher HsTnT levels, irrespective of adjudicated diagnoses, were associated with increased mortality. Most very elderly patients presenting with symptoms suggestive of an ACS undergoing HsTnT testing in EDs had elevated levels most commonly due to chronic myocardial injury. Whether any interventions can modify outcomes require prospective evaluation.

P187 Late outcomes of all patients at a single center with diabetes mellitus undergoing SYNTAX scoring after angiographic screening for the FREEDOM trial

Background

The Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multi-Vessel Disease (FREEDOM) trial randomized only a minority of screened patients with diabetes mellitus (DM) and 2-3 vessel disease (MVD), representing an high risk diabetic MVD cohort.

Methods

Consecutive patients with DM underwent angiographic screening from June 2006  to March 2010 at Liverpool Hospital, Sydney, Australia, for the FREEDOM trial; SYNTAX Scores (SS) were subsequently performed. Patients had late follow-up to determine late rates of death, non-fatal MI and stroke.

Results

Among 1263 patients with DM 833 (66%) had 0-1 vessel disease and 430 (34%) had MVD of whom 139 had prior coronary artery bypass grafting (CABG), and SS were 0 in 272, 1-9 in 336, 10-22 in 264, 23-32 in 109, and 271 patients had SS ≥33. Revascularisation was performed by coronary artery bypass grafting (CABG) in 139 (11%), 486 (38%) underwent PCI, and 638 (51%) did not undergo a revascularization procedure; respective mean ages were 63.5, 64.2 and 64.7 years; p = 0.39, and presentation rates with an ACS were 52%, 57% and 37%; p &lt; 0.05. Amongst patients with MVD, those undergoing CABG had lower rates of MACE than either PCI or medical therapy (22%, 40%, and 51% respectively; p &lt; 0.001). Kaplan-Meier curves (Figure) with respect to SS and late events are shown for: A) Death; B) Non-fatal MI; C) Death/MI/Stroke; D) Late Revascularization. Multi-variable analyses found independent predictors of late mortality were age &gt;75 (HR 6.2), prior MI (HR 1.1), prior CABG (HR 1.6); and LVEF &lt;40% (all p &lt; 0.05). Predictors of late MI were older age, ACS presentation at screening, LVEF &lt; 40% and insulin use.

Conclusions

Among diabetic patients who screened for the FREEDOM Trial, among 34% with MVD CABG was associated with lower rates of non-fatal MI and MACE compared to PCI and medical therapy. The poorest outcomes were observed in DM patients with MVD managed with medical therapy alone.

Abstract P187 Figure. SYNTAX scores &late events in diabetics

P333Late mortality after pharmaco-invasive PCI for STEMI

Background

Worldwide, and in Australia, a large proportion of patients with ST-segment elevation myocardial infarction (STEMI) are unable to undergo timely primary percutaneous coronary intervention (PCI), and so are transferred for PCI after receiving fibrinolytic therapy (so-called pharmaco-invasive PCI).

Methods

Our Hospital, the primary PCI centre for Southwest Sydney, Australia receives patients for both primary PCI and transferred post- fibrinolytic therapy for rescue or prognostic PCI. Associations were determined between late outcomes (bleeding according to Bleeding Academic Research Consortium (BARC) criteria and mortality) and reperfusion strategy, either primary PCI, or pharmaco-invasive PCI, in patients undergoing PCI for STEMI during hospitalization.

Results

Among 2083 consecutive patients (80% male) with STEMI who underwent PCI (1076 [52%] primary PCI and 1007 [48%] pharmaco-invasive PCI), mortality at 3 years was 8.7%,11.1% after primary PCI and 6.2% after pharmaco-invasive PCI (9.4% after rescue PCI and 4.6% after prognostic PCI); p<0.001 (Figure). Rates of type 2–5 BARC bleeding post-PCI were 35% after primary PCI and 24% after pharmaco-invasive PCI (42% after rescue PCI and 15% after prognostic PCI); p<0.001. while the rate of major bleeding type 3b-5 were 5% after primary PCI and 3% after pharmaco-invasive PCI (8% after rescue PCI and 1% after prognostic PCI); p=0.112.The independent predictors of 3 year mortality were, pre-PCI cardiogenic shock HR=0.25 [95% CI: 0.16–0.39], p<0.001), age (HR=1.05 [95% CI: 1.03–1.06], p<0.001), TIMI 3 flow post-PCI (HR=5.25 [95% CI: 2.51–11.00], p≤0.001), eGFR<60mL/min/1.73m2 (HR=2.90 [95% CI: 1.93–4.34], p≤0.001), post PCI bleeding (HR=2.17 [95% CI: 1.53–3.08], p≤0.001), anterior infarction (HR=1.76 [95% CI: 1.23–2.51], p=0.002), and female gender (HR=1.56 [95% CI: 1.07–2.27], p=0.022); and primary PCI (HR=1.6 [95% CI: 1.18–2.19; p=0.003]. On multi-variable analysis, age, cardiogenic shock presentation, rescue PCI, intra-aortic balloon pump, Pre-procedural anaemia, (all p<0.001) and eGFR<60mL/min/1.73m2 (p=0.006) were associated with bleeding.

Figure 1. Late survival after primary & PI PCI

Conclusion

Among patients with STEMI who underwent pharmaco-invasive PCI had lower mortality rates than to those who had primary PCI, though procedural selection criteria may have been different; bleeding rates were similar. Among suitable patients pharmaco-invasive PCI should be evaluated in large clinical trials.

P2717Type-II MI and chronic myocardial injury rates, invasive management and 4 year mortality among consecutive patients undergoing high sensitivity troponin T testing in the emergency department

Background

In emergency departments (EDs), assessment of patients with suspected acute coronary syndromes (ACS) represents a major workload and high sensitivity troponin (HsTn) T and I levels are frequently measured. A minority of patients have final diagnosis of myocardial infarction (MI).

Methods and results

Among 2738 consecutive patients with suspected ACS presenting to ED at Liverpool Hospital, Australia, between March and June 2014, we determined the relative frequencies of 3 patient groups: type-I MI, type-II MI including chronic myocardial injury (CMI), and assessed the use of invasive and pharmacological therapies and 4-year outcomes. Adjudication of MI was according to the 4th universal definition of MI as follows: 1) type-I MI; 2) type-II MI (including acute myocardial injury), and 3) CMI. Of 995 patients (36%) median age 76 years [IQR 65–83]), with at least 2 HsTnT measurements and one >14ng/l, 727 (73%) had chronic myocardial injury, 171 (17%) had type-II MI; and 97 (9.7%) had type-I MI. Patients with type-I MI (mean age 63 years) were younger than those with type-II MI or chronic myocardial injury by 12 and 14 years respectively. The main triggering factors for type-II MI/acute injury included: sepsis (21.1%), acute heart failure (18.3%), tachyarrhythmia (16.9%), anaemia (8.6%) and a combination of factors (16%). In-hospital angiography (62% had PCI) rates were 95% for patients with type-I MI, 24% (7% PCI) for those with type-II MI and 3.4% for CMI. Mortality at 4 years was 55% for type-II MI, 44% for CMI and 18% for type-1 MI (P<0.001; Figure), though after Cox modelling adjusting for age, gender, renal function and COPD, compared to type 1 MI, type-II MI (hazard ratio 1.61 [95% CIs 0.90–2.86]; p=0.106) and CMI (hazard ratio 1.01 [95% CIs 0.59–1.74]; p=0.963) were not independently associated with increased late mortality, largely because patients with type 1 MI were a decade younger.

Conclusion

Among unselected patients undergoing HsTnT testing in EDs, type-II MI including acute myocardial injury was more common than type-I MI. Chronic myocardial injury, which occurred in 3 of 4 patients. While patients with type-II MI acute myocardial injury had higher late mortality rates than type-I MI, though after multivariable analyses mortality rates were not different.

P6443Late outcomes in patients undergoing PCI for ST elevation myocardial infarction with respect to diabetic status and completeness of revascularisation

Objectives

This paper examines the degree to which the poor prognosis of ST elevation myocardial infarction (STEMI) patients with diabetes mellitus (DM) can be attributed to incomplete revascularization (ICR).

Background

Cardiovascular disease is the most common cause of death for patients with DM; patients with DM often have complex coronary disease and ICR. In STEMI the relative impact of DM and ICR is uncertain as these two factors frequently co-exist, the potential for confounding is high.

Methods and results

Of 589 consecutive STEMI patients, 22% had DM, who compared to patients without DM were of similar age (59 years), were more often female, had more hypertension and dyslipidaemia, but less often were smokers. A residual SYNTAX Score (rSS) >8, which defined ICR, occurred in 33%. Late cardiac death [median 3.5 years] was 4% among those without DM and 12% in those with DM (p=0.002) (p<0.001), and was 3% among 396 with rSS≤8 and 12% in 193 patients with rSS>8 (p<0.001). Patients with both ICR and DM accounted for only 8% of the STEMI population but 30% of all cardiac deaths. At final follow up (3.5 years) cardiac death rates (see Figure) were 22% in patients with both DM and ICR; these were significantly higher than rates in patients with ICR but no-DM (9%, p=0.034), and those with DM and rSS≤8 (6%, p<0.019). Multivariable analysis for cardiac death found a HR for ICR of 2.89 (95% CI 1.31–6.37; p=0.009) and a HR for DM of 5.18 (95% CI 2.45–10.97, p<0.001).

Diabetes, cardiac death & rSS

Conclusions

While ICR in DM patients with STEMI predicts a significantly poorer outcome, the poor prognosis seen in patients with DM is not explained by the degree of ICR alone. Both ICR and DM contribute independently to the risk of cardiac death in STEMI patients.

A Randomized Trial of a 1-Hour Troponin T Protocol in Suspected Acute Coronary Syndromes: The Rapid Assessment of Possible Acute Coronary Syndrome in the Emergency Department With High-Sensitivity Troponin T Study (RAPID-TnT)

BACKGROUND

High-sensitivity troponin assays promise earlier discrimination of myocardial infarction. Yet, the benefits and harms of this improved discriminatory performance when incorporated within rapid testing protocols, with respect to subsequent testing and clinical events, has not been evaluated in an in-practice patient-level randomized study. This multicenter study evaluated the noninferiority of a 0/1-hour high-sensitivity cardiac troponin T (hs-cTnT) protocol in comparison with a 0/3-hour masked hs-cTnT protocol in patients with suspected acute coronary syndrome presenting to the emergency department (ED).

METHODS

Patients were randomly assigned to either a 0/1-hour hs-cTnT protocol (reported to the limit of detection [<5 ng/L]) or masked hs-cTnT reported to ≤29 ng/L evaluated at 0/3-hours (standard arm). The 30-day primary end point was all-cause death and myocardial infarction. Noninferiority was defined as an absolute margin of 0.5% determined by Poisson regression.

RESULTS

In total, 3378 participants with an emergency presentation were randomly assigned between August 2015 and April 2019. Ninety participants were deemed ineligible or withdrew consent. The remaining participants received care guided either by the 0/1-hour hs-cTnT protocol (n=1646) or the 0/3-hour standard masked hs-cTnT protocol (n=1642) and were followed for 30 days. Median age was 59 (49-70) years, and 47% were female. Participants in the 0/1-hour arm were more likely to be discharged from the ED (0/1-hour arm: 45.1% versus standard arm: 32.3%, P<0.001) and median ED length of stay was shorter (0/1-hour arm: 4.6 [interquartile range, 3.4-6.4] hours versus standard arm: 5.6 (interquartile range, 4.0-7.1) hours, P<0.001). Those randomly assigned to the 0/1-hour protocol were less likely to undergo functional cardiac testing (0/1-hour arm: 7.5% versus standard arm: 11.0%, P<0.001). The 0/1-hour hs-cTnT protocol was not inferior to standard care (0/1-hour arm: 17/1646 [1.0%] versus 16/1642 [1.0%]; incidence rate ratio, 1.06 [ 0.53-2.11], noninferiority P value=0.006, superiority P value=0.867), although an increase in myocardial injury was observed. Among patients discharged from ED, the 0/1-hour protocol had a negative predictive value of 99.6% (95% CI, 99.0-99.9%) for 30-day death or myocardial infarction.

CONCLUSIONS

This in-practice evaluation of a 0/1-hour hs-cTnT protocol embedded in ED care enabled more rapid discharge of patients with suspected acute coronary syndrome. Improving short-term outcomes among patients with newly recognized troponin T elevation will require an evolution in management strategies for these patients.

CLINICAL TRIAL REGISTRATION

URL: https://www.anzctr.org.au. Unique identifier: ACTRN12615001379505.

The appropriateness of coronary investigation in myocardial injury and type 2 myocardial infarction (ACT-2): A randomized trial design

BACKGROUND

Elevated troponin level findings among patients presenting with suspected acute coronary syndrome (ACS) or another intercurrent illness undeniably identifies patients at increased risk of mortality. Whilst enhancing our capacity to discriminate risk, the use of high-sensitivity troponin assays frequently identifies patients with myocardial injury (i.e. troponin rise without acute signs of myocardial ischemia) or type 2 myocardial infarction (T2MI; oxygen supply-demand imbalance). This leads to the clinically challenging task of distinguishing type 1 myocardial infarction (T1MI; coronary plaque rupture) from myocardial injury and T2MI in the context of concurrent acute illness. Diagnostic discernment in this context is crucial because MI classification has implications for further investigation and care. Early invasive management is of well-established benefit among patients with T1MI. However, the appropriateness of this investigation in the heterogeneous context of T2MI, where there is high competing mortality risk, remains unknown. Although coronary angiography in T2MI is advocated by some, there is insufficient evidence in existing literature to support this opinion as highlighted by current national guidelines.

OBJECTIVE

The objective is to evaluate the clinical and economic impact of early invasive management with coronary angiography in T2MI in terms of all-cause mortality and cost effectiveness.

DESIGN

This prospective, pragmatic, multicenter, randomized trial among patients with suspected supply demand ischemia leading to troponin elevation (n=1,800; T2MI [1,500], chronic myocardial injury [300]) compares the impact of invasive angiography (or computed tomography angiography as per local preference) within 5 days of randomization versus conservative management (with or without functional testing at clinician discretion) on all-cause mortality by 2 years. Randomized treatment allocation will be stratified by baseline estimated risk of mortality using the Acute Physiology, Age, and Chronic Health Evaluation (APACHE) III risk score. Cost-effectiveness will be evaluated by follow-up on clinical events, quality of life, and resource utilization over 24 months.

SUMMARY

Ascertaining the most appropriate first-line investigative strategy for these commonly encountered high-risk T2MI patients in a randomized comparative study will be pivotal in informing evidence-based guidelines that lead to better patient and health care outcomes.

The impact of incomplete revascularization on early and late outcomes in ST-elevation myocardial infarction

BACKGROUND

In ST-elevation myocardial infarction (STEMI) in patients with multivessel disease, there is a lack of consensus regarding the importance of complete revascularization and the timing of treatment of nonculprit stenoses. Our objective was to investigate the impact of incomplete revascularization in STEMI patients using the residual Synergy Between PCI with TAXUS and Cardiac Surgery score (rSS) to define completeness of revascularization.

METHODS

This study examined associations between incomplete revascularization, determined by the rSS, and the combined outcome of cardiac death and myocardial infarction (MI). Patients were divided into groups: rSS = 0 (complete revascularization), rSS = 1-8 (incomplete revascularization with a low burden of residual disease), or rSS >8 (incomplete revascularization with a high burden of residual disease).

RESULTS

The rSS score was calculated in 589 consecutive patients; 25% had an rSS of 0, 42% rSS 1-8, and 33% rSS >8. At median follow-up of 3.5 years, cardiac death and MI occurred in 5% of rSS = 0 patients, 15% rSS = 1-8, and 26% with rSS >8 (P < .001). The rSS was powerful independent predictor of cardiac death and MI (hazard ratio 5.05, CI 2.89-12.00, rSS >8 vs rSS 0, P < .001 and hazard ratio 2.96, CI 1.31-6.69, rSS = 1-8 vs rSS = 0, P = .009), respectively, and an independent predictor of mortality, MI, unplanned revascularization, and major adverse cardiovascular events.

CONCLUSIONS

In patients with STEMI, the rSS independently predicts cardiac death and MI. Patients with an rSS >8 had substantially higher rates of cardiac death or MI. The rSS can be used to define incomplete revascularization in STEMI and predict adverse outcomes.

Combined testing of copeptin and high-sensitivity cardiac troponin T at presentation in comparison to other algorithms for rapid rule-out of acute myocardial infarction

BACKGROUND

We aimed to directly compare the diagnostic and prognostic performance of a dual maker strategy (DMS) with combined testing of copeptin and high-sensitivity (hs) cardiac troponin T (cTnT) at time of presentation with other algorithms for rapid rule-out of acute myocardial infarction (AMI).

METHODS

922 patients presenting to the emergency department with suspected AMI and available baseline copeptin measurements qualified for the present TRAPID-AMI substudy. Diagnostic measures using the DMS (copeptin <10, <14 or < 20 pmol/L and hs-cTnT≤14 ng/L), the 1 h-algorithm (hs-cTnT<12 ng/L and change <3 ng/L at 1 h), as well as the hs-cTnT limit-of-blank (LoB, <3 ng/L) and -detection (LoD, <5 ng/L) were compared. Outcomes were assessed as combined end-points of death and myocardial re-infarction.

RESULTS

True-negative rule-out using the DMS could be achieved in 50.9%-62.3% of all patients compared to 35.0%, 45.3% and 64.5% using LoB, LoD or the 1 h-algorithm, respectively. The DMS showed NPVs of 98.1%-98.3% compared to 99.2% for the 1 h-algorithm, 99.4% for the LoB and 99.3% for the LoD. Sensitivities were 93.5%-94.8%, as well as 96.8%, 98.7% and 98.1%, respectively. Addition of clinical low-risk criteria such as a HEART-score ≤ 3 to the DMS resulted in NPVs and sensitivities of 100% with a true-negative rule-out to 33.8%-41.6%. Rates of the combined end-point of death/MI within 30 days ranged between 0.2% and 0.3% for all fast-rule-out protocols.

CONCLUSION

Depending on the applied copeptin cut-off and addition of clinical low-risk criteria, the DMS might be an alternative to the hs-cTn-only-based algorithms for rapid AMI rule-out with comparable diagnostic measures and outcomes.

Clinical and Angiographic Predictors of Mortality in Sudden Cardiac Arrest Patients Having Cardiac Catheterisation: A Single Centre Registry

BACKGROUND

Immediate cardiac catheterisation (CC) is recommended in ST-elevation myocardial infarction (STEMI) following sudden cardiac arrest (SCA). Guidelines advise urgent CC for SCA patients without-STEMI, at clinician discretion. We examined the clinical and angiographic factors predicting mortality in SCA patients having CC.

METHODS

Consecutive SCA patients having CC at Liverpool Hospital, Sydney (January 2011-September 2015) were retrospectively analysed. Patient data were retrieved from hospital records, and angiographic SYNTAX scores (SS) were quantified online. Independent predictors of mortality were derived using multivariate logistic analysis.

RESULTS

The study cohort comprised 104 SCA patients; mean age 61±12years, and 79% male. Immediate CC (<2hours post-SCA) was performed in 35% overall. Compared to the without-STEMI subgroup, STEMI patients had more ventricular fibrillation (91 vs 50%; p<0.0001), and higher mean peak serum high-sensitivity troponin-T (8.25±14.7 vs 1.97±6.13 ug/L; p=0.006); in the context of higher median SS (18 vs 6.5; p=0.002) and target-lesion SS (tSS, 10 vs 0; p<0.001). Percutaneous coronary intervention (PCI; 75 vs 23%; p<0.0001) and target vessel revascularisation (11 vs 0%; p=0.005) were more frequent for STEMI. All-cause mortality was 39%, at 1.3±1.5years follow-up. Independent mortality predictors were: delayed CC (HR 4.08), serum lactate >7mmol/L (HR 3.47), and tSS (HR 1.05).

CONCLUSIONS

Elevated serum lactate, tSS, and delayed CC, were predictive of longer-term mortality in SCA patients having CC. Late CC in patients without-STEMI suggest scope for improvement in real-world systems of care. Closer scrutiny of target lesion complexity may aid prognostication in SCA survivors.

National Heart Foundation of Australia and Cardiac Society of Australia and New Zealand: Australian clinical guidelines for the management of acute coronary syndromes 2016

INTRODUCTION

The modern care of suspected and confirmed acute coronary syndrome (ACS) is informed by an extensive and evolving evidence base. This clinical practice guideline focuses on key components of management associated with improved clinical outcomes for patients with chest pain or ACS. These are presented as recommendations that have been graded on both the strength of evidence and the likely absolute benefit versus harm. Additional considerations influencing the delivery of specific therapies and management strategies are presented as practice points.

MAIN RECOMMENDATIONS

This guideline provides advice on the standardised assessment and management of patients with suspected ACS, including the implementation of clinical assessment pathways and subsequent functional and anatomical testing. It provides guidance on the: diagnosis and risk stratification of ACS; provision of acute reperfusion therapy and immediate post-fibrinolysis care for patients with ST segment elevation myocardial infarction; risk stratification informing the use of routine versus selective invasive management for patients with non-ST segment elevation ACS; administration of antithrombotic therapies in the acute setting and considerations affecting their long term use; and implementation of an individualised secondary prevention plan that includes both pharmacotherapies and cardiac rehabilitation. Changes in management as a result of the guideline: This guideline has been designed to facilitate the systematic integration of the recommendations into a standardised approach to ACS care, while also allowing for contextual adaptation of the recommendations in response to the individual's needs and preferences. The provision of ACS care should be subject to continuous monitoring, feedback and improvement of quality and patient outcomes.

National Heart Foundation of Australia and Cardiac Society of Australia and New Zealand: Australian clinical guidelines for the management of acute coronary syndromes 2016

INTRODUCTION

The modern care of suspected and confirmed acute coronary syndrome (ACS) is informed by an extensive and evolving evidence base. This clinical practice guideline focuses on key components of management associated with improved clinical outcomes for patients with chest pain or ACS. These are presented as recommendations that have been graded on both the strength of evidence and the likely absolute benefit versus harm. Additional considerations influencing the delivery of specific therapies and management strategies are presented as practice points.

MAIN RECOMMENDATIONS

This guideline provides advice on the standardised assessment and management of patients with suspected ACS, including the implementation of clinical assessment pathways and subsequent functional and anatomical testing. It provides guidance on the: diagnosis and risk stratification of ACS; provision of acute reperfusion therapy and immediate post-fibrinolysis care for patients with ST segment elevation myocardial infarction; risk stratification informing the use of routine versus selective invasive management for patients with non-ST segment elevation ACS; administration of antithrombotic therapies in the acute setting and considerations affecting their long term use; and implementation of an individualised secondary prevention plan that includes both pharmacotherapies and cardiac rehabilitation. Changes in management as a result of the guideline: This guideline has been designed to facilitate the systematic integration of the recommendations into a standardised approach to ACS care, while also allowing for contextual adaptation of the recommendations in response to the individual's needs and preferences. The provision of ACS care should be subject to continuous monitoring, feedback and improvement of quality and patient outcomes.

High sensitivity cardiac troponin T in patients not having an acute coronary syndrome: results from the TRAPID-AMI study

PURPOSE

To describe the baseline, 1 hr and delta high sensitivity cardiac troponin (hs-cTnT) values in patients with suspected acute myocardial infarction (AMI) but without a final acute coronary syndrome (ACS) diagnosis.

MATERIALS AND METHODS

hs-cTnT assay for RAPID rule out of acute myocardial infarction (TRAPID-AMI) was a prospective diagnostic trial that enrolled emergency department (ED) patients with suspected AMI. Final patient diagnoses were adjudicated by a clinical events committee and subjects placed in different clinical groups: AMI, unstable angina, non-ACS cardiac, non-cardiac and unknown origin. The baseline, 1 hr and delta hs-cTnT values were analysed in the 902 non-ACS patients.

RESULTS

Amongst the 1282 studied the patient groups were 213 (17%) AMI, 167 (13%) unstable angina, 113 (9%) non-ACS cardiac, 288 (22%) non-cardiac and 501 (39%) unknown origin. The hs-cTnT values in the non-cardiac and unknown origin groups were combined. The median hs-cTnT values (ng/L) were higher (p < 0.001) in the non-ACS cardiac compared to the non-cardiac/unknown origin group at baseline (11.8, <5) and 1 hr (12.3, <5). Their negative predictive values were 0.955 (baseline) and 0.954 (1 hr) for predicting non-ACS cardiac versus non-cardiac/unknown origin diagnoses.

CONCLUSIONS

Hs-cTnT may help predict whether non-ACS ED patients have a final non-ACS cardiac or non-cardiac/unknown origin diagnoses.

A decade of improvement in the management of New Zealand ST-elevation myocardial infarction (STEMI) patients: results from the New Zealand Acute Coronary Syndrome (ACS) Audit Group national audits of 2002, 2007 and 2012

AIMS

To audit the management of ST-segment elevation myocardial infarction (STEMI) patients admitted to a New Zealand Hospital over three 14-day periods to review their number, characteristics, management and outcome changes over a decade.

METHODS

The acute coronary syndrome (ACS) audits were conducted over 14 days in May of 2002, 2007 and 2012 at New Zealand Hospitals admitting patients with a suspected or definite ACS. Longitudinal analyses of the STEMI subgroup are reported.

RESULTS

From 2002 to 2012, the largest change in management was the proportion of patients undergoing reperfusion by primary PCI from 3% to 15% and 41%; P<0.001, and the rates of second antiplatelet agent use in addition to aspirin from 14% to 62% and 98%; P<0.001. The use of proven secondary prevention medications at discharge also increased during the decade. There were also significant increases in cardiac investigations for patients, especially echocardiograms (35%, 62% and 70%, P<0.001) and invasive coronary angiograms (31%, 58% and 87%, P<0.001). Notably even in 2012, one in four patients presenting with STEMI did not receive any reperfusion therapy.

CONCLUSIONS

Substantial improvements have been seen in the management of STEMI patients in New Zealand over the last decade, in accordance with evidenced-based guideline recommendations. However, there appears to be considerable room to optimise management, particularly with the use of timely reperfusion therapy for more patients.

A randomized trial assessing the impact of three different glycoprotein IIb/IIIa antagonists on glycoprotein IIb/IIIa platelet receptor inhibition and clinical endpoints in patients with acute coronary syndromes

AIMS

To compare three glycoprotein IIb/IIIa receptor antagonists (GPIs) in terms of platelet inhibition and major adverse cardiac events (MACEs), and assess the rate of bleeding and MACEs between GPIs and coadministered P2Y12 agents.

METHODS

Eighty-three acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) with planned GPI use were randomized to receive high-dose bolus tirofiban, double-bolus eptifibatide, or abciximab followed by a 12-hour infusion. Glycoprotein IIb/IIIa platelet receptor inhibition was measured at baseline and at 10 minutes, 1 hour, and 24 hours postbolus dose. Major adverse cardiac events and bleeding complications at 30 days were documented. The incidence of MACEs and bleeding in patients receiving ticagrelor or prasugrel were compared to those given clopidogrel.

RESULTS

There were no statistically significant differences in platelet inhibition between GPIs at 10 minutes (P=.085) and 1 hour (P=.337). At 24 hours, abciximab achieved statistically significantly higher median [interquartile range] platelet inhibition (75 [65-88]%) compared to tirofiban (28 [3-56]%; P<.0001) and eptifibatide (44 [31-63]%; P=.007). There were no differences in bleeding or MACEs depending on GPI or P2Y12 inhibitor administered.

CONCLUSIONS

Glycoprotein receptor inhibitors achieve similar levels of platelet inhibition at 10 minutes and 1 hour; however, abciximab maintains this benefit 24 hours after bolus dose. We did not witness an increased rate of bleeding in patients given new potent P2Y12 inhibitors and a GPI in the modern era.

Suspected ACS Patients Presenting With Myocardial Damage or a Type 2 Myocardial Infarction Have a Similar Late Mortality to Patients With a Type 1 Myocardial Infarction: A Report From the Australian and New Zealand 2012 SNAPSHOT ACS Study

BACKGROUND

Cardiac troponin (T and I) are considered the standard markers for detection of myocardial damage and the diagnosis of acute coronary syndrome (ACS) among patients who present to an emergency department with chest pain. However, these markers can be released in other situations and may be associated with short- and long-term clinical outcomes. In this study, we examine late mortality rates among patients presenting with a suspected ACS due to an unstable coronary plaque and those patients having a non-ACS.

METHODS

4388 patients were hospitalised with suspected ACS, between 14 and 27 May 2012 in the Australia and New Zealand SNAPSHOT ACS study. Those patients were categorised in five diagnostic groups: 1) ST elevation MI (n=419); 2) non-ST elevation MI (n=1012); 3) unstable angina (n=925); 4) non-ACS diagnoses (n=837); and 5) chest pain considered unlikely ischaemic (not otherwise specified, n=1195).

RESULT

The respective mortality rates at 18 months in these groups were 16.2%, 16.3%, 6.8%, 12.8%, and 4.8%; Pearson χ²=110 p<0.001. Among non-ACS diagnoses patients (group 4) those with the highest mortality rates (cardiac (14.4%), respiratory (18.2%), sepsis (15.4%) and neoplastic (67%) diagnoses) had the highest rates of elevated troponin levels (48%, 31%, 38% and 67% respectively). By contrast, those with the lowest mortality rates (musculoskeletal (2.9%), gastrointestinal disorders (3.9%) and non-specific chest pain (7.4%)) had the lowest rate of elevated troponin levels (9%, 18% and 15.8% respectively). However, after adjusting for baseline clinical and demographic characteristics, the mortality rate at 18 months for patients with elevated troponin was similar for ACS or non-ACS diagnoses (Hazard Ratio, 95% C.I.0.98-1.07, p=0.333).

CONCLUSIONS

Among patients in the 2012 SNAPSHOT ACS study, non-ACS diagnoses characterised by high rates of elevated troponin levels had high mortality rates similar to those diagnosed with ACS. Therapies known to be effective in ACS patients, including early invasive management, should be examined in these non-ACS patients with troponin elevations within adequately powered randomised trials.