Management of Acute Coronary Syndromes in Patients in Rural Australia: The MORACS Randomized Clinical Trial.

Importance: Treatment of ST-segment elevation myocardial infarction (STEMI) in rural settings involves thrombolysis followed by transfer to a percutaneous coronary intervention-capable hospital. The first step is accurate diagnosis via electrocardiography (ECG), but one-third of all STEMI incidents go unrecognized and hence untreated. Objective: To reduce missed diagnoses of STEMI. Design, Setting, and Participants: This cluster randomized clinical trial included 29 hospital emergency departments (EDs) in rural Australia with no emergency medicine specialists, which were randomized to usual care vs automatically triggered diagnostic support from the tertiary referral hospital (management of rural acute coronary syndromes [MORACS] intervention). Patients presenting with symptoms compatible with acute coronary syndromes (ACS) were eligible for inclusion. The study was conducted from December 2018 to April 2020. Data were analyzed in August 2021. Intervention: Triage of a patient with symptoms compatible with ACS triggered an automated notification to the tertiary hospital coronary care unit. The ECG and point-of-care troponin results were reviewed remotely and a phone call was made to the treating physician in the rural hospital to assist with diagnosis and initiation of treatment. Main Outcomes and Measures: The proportion of patients with missed STEMI diagnoses. Results: A total of 6249 patients were included in the study (mean [SD] age, 63.6 [12.2] years; 48% female). Of 7474 ED presentations with suspected ACS, STEMI accounted for 77 (2.0%) in usual care hospitals and 46 (1.3%) in MORACS hospitals. Missed diagnosis of STEMI occurred in 27 of 77 presentations (35%) in usual care hospitals and 0 of 46 (0%) in MORACS hospitals (P < .001). Of eligible patients, 48 of 75 (64%) in the usual care group and 36 of 36 (100%) in the MORACS group received primary reperfusion (P < .001). In the usual care group, 12-month mortality was 10.3% (n = 8) vs 6.5% (n = 3) in the MORACS group (relative risk, 0.64; 95% CI, 0.18-2.23). Patients with missed STEMI diagnoses had a mortality of 25.9% (n = 7) compared with 2.0% (n = 1) for those with accurately diagnosed STEMI (relative risk, 13.2; 95% CI, 1.71-102.00; P = .001). Overall, there were 6 patients who did not have STEMI as a final diagnosis; 5 had takotsubo cardiomyopathy and 1 had pericarditis. There was no difference between groups in the rate of alternative final diagnosis. Conclusion and Relevance: The findings indicate that MORACS diagnostic support service reduced the proportion of missed STEMI and improved the rates of primary reperfusion therapy. Accurate diagnosis of STEMI was associated with lower mortality. Trial Registration: anzctr.org.au Identifier: ACTRN12619000533190.

Targeting elevated left ventricular end-diastolic pressure following primary percutaneous coronary intervention for ST-segment elevation myocardial infarction - a phase one safety and feasibility study.

INTRODUCTION: Elevated left ventricular end diastolic pressure (LVEDP) is an independent predictor of mortality and heart failure in patients with ST-segment elevation myocardial infarction (STEMI). Whether lowering elevated LVEDP improves outcomes remains unknown. METHODS: This non-randomized, single blinded study with prospective enrolment and sequential group allocation recruited patients undergoing primary percutaneous coronary intervention for STEMI with LVEDP ⩾ 20 mmHg measured immediately after primary percutaneous coronary intervention. The intervention arm (n=10) received furosemide 40 mg intravenous bolus plus escalating doses of glyceryl trinitrate (100 µg per min to a maximum of 1000 µg) during simultaneous measurement of LVEDP. The control group (n=10) received corresponding normal saline boluses with simultaneous measurement of LVEDP (10 readings over 10 min). Efficacy endpoints were final LVEDP achieved, and the dose of glyceryl trinitrate needed to reduce LVEDP by ⩾ 20%. Safety endpoint was symptomatic hypotension (systolic blood pressure < 90 mmHg). RESULTS: From 1 April 2017 to 23 August 2017 we enrolled 20 patients (age: 64±9 years, males: 60%, n=12, anterior STEMI: 65%, n=13). The mean LVEDP for the whole cohort (n=20) was 29±4 mmHg (intervention group: 28±3 mmHg vs. control group: 31±5 mmHg; p=0.1). The LVEDP dropped from 28±3 to 16±2 mmHg in the glyceryl trinitrate + furosemide group (p <0.01) but remained unchanged in the control group. The median dose of glyceryl trinitrate required to produce ⩾ 20% reduction in LVEDP in the intervention group was 200 µg (range: 100-800). One patient experienced asymptomatic decline in systolic blood pressure to below 90 mmHg. There was no correlation between LVEDP and left ventricular ejection fraction. CONCLUSION: The administration of glyceryl trinitrate plus furosemide in patients with elevated LVEDP following primary percutaneous coronary intervention for STEMI safely reduces LVEDP.

Trends in the Incidence of First Acute Myocardial Infarction in Metropolitan and Regional Areas of the Hunter Region.

INTRODUCTION: There is conflicting information regarding the contemporary incidence of first acute myocardial infarction (AMI) in Australia. We sought to document the regional variations in first AMI incidence in a large health district. METHODS: We identified all patients presenting with first AMI in the Hunter region of New South Wales from 2004 to 2013. We calculated age and gender adjusted incidence of AMI and evaluated differences between patients from regional and metropolitan areas. We assessed 30-day and 12-month outcomes, including mortality, through linkage with the NSW Registry of Births Deaths and Marriages. RESULTS: The incidence of first AMI in regional areas was persistently higher throughout the study compared to metropolitan areas (IRR 1.244; 95% CI 1.14-1.35; p≤0.001). There were no significant differences between regional and metropolitan areas in 30-day and 12-month outcomes following presentation with first AMI. CONCLUSIONS: The study demonstrates persistently higher rates in regional compared to metropolitan areas, supporting the need for implementation of targeted intervention and prevention strategies.

Keys to Achieving Target First Medical Contact to Balloon Times and Bypassing Emergency Department More Important Than Distance.

BACKGROUND: Australian guidelines advocate primary percutaneous coronary intervention (PPCI) as the reperfusion strategy of choice for ST elevation myocardial infarction (STEMI) in patients in whom it can be performed within 90 minutes of first medical contact; otherwise, fibrinolytic therapy is preferred. In a large health district, the reperfusion strategy is often chosen in the prehospital setting. We sought to identify a distance from a PCI centre, which made it unlikely first medical contact to balloon time (FMCTB) of less than 90 minutes could be achieved in the Hunter New England health district and to identify causes of delay in patients who were triaged to a PPCI strategy. METHODS AND RESULTS: We studied 116 patients presenting via the ambulance service with STEMI from January 2016 to December 2016. In patients who were taken directly to the cardiac catheterisation lab, a maximum distance of 50 km from hospital resulted in 75% of patients receiving PCI within 90 minutes and approximately 95% of patients receiving PCI within 120 minutes. Patients who bypassed the emergency department (ED) were significantly more likely to have FMCTB of less than 90 minutes (p < 0.001) despite having a longer travel distance (28.5 km versus 17.4 km, p < 0.001). Patients transiting via the ED were significantly more likely to present out of hours (60 versus 24.2% p < 0.001). CONCLUSIONS: Patients who do not bypass the ED have a longer FMCTB across all spectrum of distances from the PCI centre; therefore, bypassing the ED is key to achieving target FMCTB times. Using a cutoff distance of 50 km may reduce human error in estimating travel time to our PCI centre and thereby identifying patients who should receive prehospital thrombolysis.

Mortality and Readmission Following Hospitalisation for Heart Failure in Australia: A Systematic Review and Meta-Analysis.

BACKGROUND: Heart failure (HF) is a common, costly condition with an increasing burden on Australian health care system resources. Knowledge of the burden of HF on patients and on the health system is important for resource allocation. This study is the first systematic review to estimate the mortality and readmission rates after hospitalisation for HF in the Australian population. METHODS: We searched for studies of HF hospitalisation in Australia published between January 1990 and May 2016, using a systematic search of PubMed, Medline, Scopus, Web of Science, EMBASE and Cochrane Library databases. Studies reporting 30-day and/or 1-year outcomes for mortality or readmission following hospitalisation were eligible and included in this study. RESULTS: Out of 2889 articles matching the initial search criteria, a total of 13 studies representing 67,255 patients were included in the final analysis. The pooled mean age of heart failure patients was 76.3 years and 51% were male (n=34,271). The pooled estimated 30-day and 1-year all-cause mortality were 8% and 25% respectively. The pooled estimated 30-day and 1-year all-cause readmission rates were 20% and 56% respectively. There is a high prevalence of comorbidities in heart failure patients. There were limited data on readmission and mortality in rural patients and Indigenous people. CONCLUSIONS: Heart failure hospitalisations in Australia are followed by substantial readmission and mortality rates.

ST elevation myocardial infarction in patients with anomalous left main coronary artery: Case series and review of the literature.

Anomalous left main coronary artery is rare. We present four cases where anomalous left main coronary artery was diagnosed during emergent cardiac catheterization for ST elevation myocardial infarction. Procedural characteristics, technical challenges, and relevant literature are discussed.

Outcomes following heart failure hospitalization in a regional Australian setting between 2005 and 2014.

AIMS: The aim of the current study is to examine 10 year trends in mortality and readmission following heart failure (HF) hospitalization in metropolitan and regional Australian settings. METHODS AND RESULTS: We identified all index HF hospitalizations in the Hunter New England region from 2005 to 2014, using a 10 year 'look back' period. The primary endpoint was a composite of all-cause mortality or all-cause readmission at 1 year. Secondary endpoints included all-cause mortality, all-cause readmission, and HF readmission at 30 days and 1 year. We used logistic regression to explore the predictors of the composite outcome of either all-cause death or readmission at 1 year. There were 12 114 patients admitted with a first episode of HF between 2005 and 2014, followed up until death or the end of 2015. The mean age was 78 ± 12 years and 49% (n = 5906) were male. A total of 4831 (40%) resided in regional areas and the remainder in metropolitan areas. One hundred sixty-eight patients (1.4%) were Aboriginal. Approximately 69% of patients had either died or been readmitted for any cause within 12 months of their index event. The 30 day and 1 year all-cause mortality rates were 13% and 32%, respectively, with no change in the trend over the study period. Age, socio-economic disadvantage, ischaemic heart disease, renal failure, and chronic lower respiratory disease were predictors of the primary endpoint. CONCLUSIONS: Heart failure hospitalizations are followed by high rates of death or readmission. There was no change in this composite endpoint over the 10 year study period.

Prognostic Value of LVEDP in Acute Myocardial Infarction: a Systematic Review and Meta-Analysis.

Left ventricular end-diastolic pressure (LVEDP) is an easily obtained, physiologically integrative measure of total LV function. LVEDP may be a useful prognostic measure in patients with acute myocardial infarction and utilised to guide medical therapy and assess risk for post myocardial infarction heart failure. To assess the utility of LVEDP as a prognostic measure in patients presenting with acute myocardial infarction. We performed an unrestricted search of electronic databases (1946 to March 2017) using a predefined search strategy. Publications were included if patients had an acute coronary syndrome and LVEDP was measured by cardiac catheterisation and included outcome data specifying major adverse cardiac events. Two reviewers performed independent study selection, data abstraction and quality assessment by using the Cochrane tool for randomised trials and the ROBINS-I tool for non-randomised studies. Our search identified 8637 patients in seven studies. In patients with elevated LVEDP and STEMI, there was a significantly increased risk of 30-day death (three studies, 5372 participants; RR 1.9; 95% CI 1.4-2.7; p < 0.001; I 2 = 35.3%) and heart failure (two studies, 2574 participants; RR 2.9; 95% CI 1.9-4.5; p = < 0.001; I 2 = 0.0%). There was no significant increase in risk of 30 day reinfarction (RR 1.25; 95% CI 0.77-2.1; p = 0.37; I 2 = 41.3%). Elevated LVEDP measured during cardiac catheterisation for acute myocardial infarction appears to be a predictor of heart failure and mortality.

Retrieval of Embolized Amplatzer Patent Foramen Ovale Occlusion Device: Issues Related to Late Recognition.

Embolization of a percutaneous patent foramen ovale (PFO) closure device is a rare but serious complication. While early, periprocedural device embolization can normally be managed with snare and percutaneous retrieval, late embolization requires a different management strategy due to inability of the device to deform to allow passage into a large caliber sheath. We present a case of asymptomatic device embolization recognized six months following implantation and discuss the challenges encountered in successfully retrieving the device.

Disparities in the incidence of acute myocardial infarction: long-term trends from the Hunter region.

BACKGROUND: Trends in the incidence of acute myocardial infarction (AMI) provide important information for healthcare providers and can allow for accurate planning of future health needs and targeted interventions in areas with an excess burden of cardiovascular disease. AIM: To investigate the regional variations in AMI incidence in the Hunter region. METHODS: Incident cases of AMI identified between 1996 and 2013 from the Hunter New England Health Cardiac and Stroke Outcomes Unit were prospectively collected for this study. We calculated crude and age-adjusted incidence of AMI over an 18-year period and explored differences in remoteness, age, sex and indigenous status. RESULTS: During 1996-2013, a total of 15 480 cases of AMI were identified. There was a significantly higher incidence of AMI in patients from regional areas compared to patients from metropolitan areas. More importantly, while rates of AMI declined by 28% in metropolitan patients, they increased by 8% in regional patients. Males had higher rates of AMI throughout the study period than females, however there was trend over time towards a reduction in AMI incidence in males that was not seen in females. The age-adjusted incidence of AMI for indigenous patients increased by 48% from 2007 to 2013, compared to a 23% decrease in non-indigenous patients. CONCLUSION: Between 1996 and 2013 in the Hunter region, the adjusted incidence of AMI increased for regional patients compared to metropolitan patients with a trend towards a higher adjusted incidence of AMI in the indigenous population.

Heart Failure Hospitalisations in the Hunter New England Area Over 10 years. A Changing Trend.

BACKGROUND: Heart failure carries a major burden on our health system, mainly related to the high rate of hospital admission. An understanding of the recent trends in heart failure hospitalisation is essential to the future allocation of health resources. Our aim is to analyse the temporal trends in heart failure hospitalisation. METHODS: We extracted all separations in the Hunter New England Local Health District between 2005-2014 (n=40,119) with an ICD 10 code for heart failure (I-50) in the first four diagnoses on discharge. The numbers of hospitalisations were age-standardised to the 2001 Australian population and compared based on gender and remoteness. RESULTS: There was a decline in the age-standardised hospitalisation. However, there was a clear inflection point between 2009-2010, after which the decline levelled off. The absolute number of hospitalisations increased between 2010 and 2014. Heart failure hospitalisation was higher in males compared to females and rural compared to metropolitan inhabitants. CONCLUSION: The gains in heart failure treatment noted in recent years seem to have come to an end. Patients aged 75 years and older are contributing the majority of age-standardised hospitalisations.

Pre-hospital thrombolysis in ST-segment elevation myocardial infarction: a regional Australian experience.

OBJECTIVE: The system of care in the Hunter New England Local Health District for patients with ST-segment elevation myocardial infarction (STEMI) foresees pre-hospital thrombolysis (PHT) administered by paramedics to patients more than 60 minutes from the cardiac catheterisation laboratory (CCL), and primary percutaneous coronary intervention (PCI) at the CCL for others. We assessed the safety and effectiveness of the pre-hospital diagnosis strategy, which allocates patients to PHT or primary PCI according to travel time to the CCL. DESIGN, SETTING AND PARTICIPANTS: Prospective, non-randomised, consecutive, single-centre case series of STEMI patients diagnosed on the basis of a pre-hospital electrocardiogram (ECG), from August 2008 to August 2013. All patients were treated at the tertiary referral hospital (John Hunter Hospital, Newcastle). MAIN OUTCOME MEASURES: The primary efficacy endpoint was all-cause mortality at 12 months; the primary safety endpoint was bleeding. RESULTS: STEMI was diagnosed in 484 patients on the basis of pre-hospital ECG; 150 were administered PHT and 334 underwent primary PCI. The median time from first medical contact (FMC) to PHT was 35 minutes (IQR, 28-43 min) and to balloon inflation 130 minutes (IQR, 100-150 min). In the PHT group, 37 patients (27%) needed rescue PCI (median time, 4 h; IQR, 3-5 h). The 12-month all-cause mortality rate was 7.0% (PHT, 6.7%; PCI, 7.2%). The incidence of major bleeding (TIMI criteria) in the PHT group was 1.3%; no patients in the primary PCI group experienced major bleeding. CONCLUSION: PHT can be delivered safely by paramedical staff in regional and rural Australia with good clinical outcomes.

Long Term Follow-up of Pulmonary Vein Isolation Using Cryoballoon Ablation.

BACKGROUND: Cryoballoon ablation is an established catheter-based approach to treating atrial fibrillation (AF). There is little data regarding the long-term efficacy of this approach. METHODS: We enrolled 200 consecutive patients with symptomatic AF who had failed therapy with at least one anti-arrhythmic medication and followed them for five years. The primary efficacy endpoint was symptomatic recurrence of AF after a single cryoballoon ablation procedure. RESULTS: Two hundred patients formed the study group. Median follow-up was 56 months. Following a single procedure, 46.7% of patients with paroxysmal AF remained free of symptomatic recurrence of AF compared to 35.6% of patients with persistent AF. When allowing for repeat ablations, at the end of the follow-up period 53.3% of patients in the paroxysmal group remained free of symptomatic AF compared to 47.5% in the persistent group. The rate of complications was low. CONCLUSIONS: Cryoballoon ablation is an effective catheter-based approach for treating symptomatic AF with a low risk of complications.

Stent-graft repair of a giant saphenous vein graft aneurysm.

Saphenous vein graft aneurysms are an uncommon late complication of coronary artery bypass surgery (CABG). Management strategies include surgical revision, percutaneous closure using covered stent grafts, coil embolisation, vascular plug insertion and ethylene vinyl alcohol copolymer injection. We report a case of a very large saphenous vein graft aneurysm successfully treated with a covered stent graft.