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We assessed sex differences in treatment and outcomes in ST-segment elevation myocardial infarction (STEMI) patients treated with primary percutaneous coronary intervention (PCI).Historically, delays to timely reperfusion and poorer outcomes have been described in women who suffer STEMI. However, whether these sex discrepancies still exist with contemporary STEMI treatment remains to be evaluated.Consecutive STEMI patients treated with primary PCI patients over a 10-year period (January 1, 2010 to December 31, 2019) from a tertiary referral center were assessed. Comparisons were performed between patient's sex. Primary outcomes were 30-day and 1-year mortality. Secondary outcomes were STEMI performance measures.Most patients (n = 950; 76%) were male. Females were on average older (66.8 vs. 61.4 years males; p 0.001). Prehospital treatment delays did not differ between sexes (54 min [IQR: 44-65] females vs. 52 min [IQR: 43-62] males; p = 0.061). STEMI performance measures (door-to-balloon, first medical contact-to-balloon [FMCTB]) differed significantly with longer median durations in females and fewer females achieving FMCTB 90 min (28% females vs. 39% males; p 0.001). Women also experienced greater rates of initial radial arterial access failure (11.3% vs. 3.1%; p 0.001). However, there were no significant sex differences in crude or adjusted mortality between sexes at 30-days (3.6% male vs. 5.1% female; p = 0.241, adjusted OR: 1.1, 95% CI: 0.5-2.2, p = 0.82) or at 1-year (4.8% male vs. 6.8% female; p = 0.190, adjusted OR: 1.0, (95% CI: 0.5-1.8; p = 0.96).Small discrepancies between sexes in measures of timely reperfusion for STEMI still exist. No significant sex differences were observed in either 30-day or 1-year mortality.

BackgroundPrehospital activation of the cardiac catheter laboratory is associated with significant improvements in ST-segment elevation myocardial infarction (STEMI) performance measures. However, there is equivocal data, particularly within Australia regarding its influence on mortality. We assessed the association of prehospital activation on performance measures and mortality in STEMI patients treated with primary percutaneous coronary intervention (PCI) from the Queensland Cardiac Outcomes Registry (QCOR).MethodsConsecutive ambulance transported STEMI patients treated with primary PCI were analysed from 1stJanuary 2017 to 31stDecember 2020 from the QCOR. The total and direct effects of prehospital activation on the primary outcomes (30-day and 1-year cardiovascular mortality) were estimated using logistic regression analyses. Secondary outcomes were STEMI performance measures.ResultsAmong 2498 patients (mean age: 62.2 ± 12.4 years; 79.2% male), 73% underwent prehospital activation. Median door-to-balloon (DTB) time (34mins [26-46] vs 86 mins [68-113]; pConclusionsPrehospital activation of cardiac catheterisation laboratory for primary PCI was associated with significantly shorter time to reperfusion, achievement of STEMI performance measures and lower 30-day and 1-year cardiovascular mortality.Clinical PerspectiveIn patients who suffer STEMI, prehospital activation of the cardiac catheter laboratory and initiation of medical therapy is associated with shorter time to reperfusion, greater achievement of performance measures and lower cardiovascular mortalityThis study adds to the existing literature and demonstrates that a standardised prehospital activation strategy can be implemented on a large scaleWidespread implementation of standardised prehospital activation strategies may offer opportunity to expedite STEMI care and improve outcomes

The subcutaneous (S-) implantable cardioverter-defibrillator (ICD) is an alternative to the transvenous (TV-) ICD that is increasingly implanted in younger patients; data on the safety and effectiveness of the S-ICD in older patients are lacking.The purpose of this study was to compare outcomes among older patients who received an S- or TV-ICD.The authors compared S-ICD and single-chamber TV-ICD implants in Fee-For-Service Medicare beneficiaries using the National Cardiovascular Data Registry ICD Registry. Outcomes were ascertained from Medicare claims data. Cox regression or competing-risk models (with TV-ICD as reference) with overlap weights were used to compare death and nonfatal outcomes (device reoperation, device removal for infection, device reoperation without infection, and cardiovascular admission), respectively. Recurrent all-cause readmissions were compared using Anderson-Gill models.A total of 16,063 patients were studied (age 72.6 ± 5.9 years, 28.4% women, ejection fraction 28.3 ± 8.9%). Compared with TV-ICD patients (n = 15,072), S-ICD patients (n = 991, 6.2% overall) were more often Black, younger, and dialysis dependent and less likely to have history of atrial fibrillation or flutter. In adjusted analyses, there were no differences between device type and risk of all-cause mortality (HR: 1.020; 95% CI: 0.819-1.270), device reoperation (subdistribution [s] HR: 0.976; 95% CI: 0.645-1.479), device removal for infection (sHR: 0.614; 95% CI: 0.138-2.736), device reoperation without infection (sHR: 0.975; 95% CI: 0.632-1.506), cardiovascular readmission (sHR: 1.087; 95% CI: 0.912-1.295), or recurrent all-cause readmission (HR: 1.072; 95% CI: 0.990-1.161).In a large representative national cohort of older patients undergoing ICD implantation, risk of death, device reoperation, device removal for infection, device reoperation without infection, and cardiovascular and all-cause readmission were similar among S- and TV-ICD recipients.

Objective To evaluate the characteristics and predictors of unplanned readmission within 30 days of hospitalisation for the treatment of peripheral arterial disease (PAD) in Australia and New Zealand. Design Analysis of hospitalisations data in the Admitted Patient Collection for each Australian state and territory and the New Zealand National Minimum Dataset (Hospital Events). Setting All public and 80% of private hospitals in Australia and New Zealand. Participants Adults (18 years or older) hospitalised with a primary or conditional secondary diagnosis of PAD during 1 January 2010 - 31 December 2015. Main outcome measure Rate of unplanned readmission (any cause) within 30 days of hospitalisation with PAD. Results Of 104 979 admissions included in our analysis (mean patient age, 73.7 years; SD, 12.4 years), 9765 were followed by at least one unplanned readmission within 30 days of discharge (9.3%): 3395 within one week (34.8%) and 7828 within three weeks (80.2%). The most frequent readmission primary diagnoses were atherosclerosis (1477, 15.3%), type 2 diabetes (1057, 10.8%), and "complications of procedures not elsewhere classified" (963, 9.9%). Readmission was more frequent after acute (4830 of 26 304, 18.4%) than elective PAD hospitalisations (4935 of 78 675, 6.3%), but the readmission characteristics were similar. Factors associated with greater likelihood of readmission included acute PAD hospitalisations (odds ratio [OR], 2.04; 95% CI, 1.96-2.17), surgical intervention during the PAD hospitalisation (OR, 1.74; 95% CI, 1.64-1.84), and chronic limb-threatening ischaemia (OR, 1.55; 95% CI, 1.47-1.63). Conclusion Unplanned readmissions within 30 days of hospitalisation for PAD are often for potentially preventable reasons. Their number should be reduced to improve clinical outcomes for people with PAD.

Background: High-sensitivity cardiac troponin (hs-cTn) laboratory assays are used to rule out myocardial infarction (MI) on presentation, but prolonged result turnaround times can delay patient management. Our primary aim was to identify patients at low risk of index MI using a rapid point-of-care (POC) whole-blood hs-cTnI assay at presentation with potential early patient discharge. Methods: Consecutive patients presenting to the emergency department from 2 prospective observational studies with suspected acute coronary syndrome were enrolled. A POC hs-cTnI assay (Atellica VTLi) threshold using whole blood at presentation, which resulted in a negative predictive value of ≥99.5% and sensitivity of >99% for index MI, was derived (SEIGE [Safe Emergency Department Discharge Rate]) and validated with plasma (SAMIE [Suspected Acute Myocardial Infarction in Emergency]). Event adjudications were established with hs-cTnI assay results from routine clinical care. The primary outcome was MI at 30 days. Results: A total of 1086 patients (8.1% with MI) were enrolled in a US derivation cohort (SEIGE) and 1486 (5.5% MI) in an Australian validation cohort (SAMIE). A derivation whole-blood POC hs-cTnI concentration of Conclusions: A POC whole-blood hs-cTnI assay permits accessible, rapid, and safe exclusion of MI and may expedite discharge from the emergency department. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04772157. URL: https://www.australianclinicaltrials.gov.au/anzctr_feed/form ; Unique identifier: 12621000053820.

Objective: To assess long term survival and patient characteristics associated with survival following acute myocardial infarction (AMI) in Australia and New Zealand. Design: Cohort study. Setting, participants: All patients admitted with AMI (ICD-10-AM codes I21.0‒I21.4) to all public and most private hospitals in Australia and New Zealand during 2009‒2015. Main outcome measure: All-cause mortality up to seven years after an AMI. Results: 239 402 initial admissions with AMI were identified; the mean age of the patients was 69.3 years (SD, 14.3 years), 154 287 were men (64.5%), and 64 335 had ST-elevation myocardial infarction (STEMI; 26.9%). 7-year survival after AMI was 62.3% (STEMI, 70.8%; non-ST-elevation myocardial infarction [NSTEMI], 59.2%); survival exceeded 85% for people under 65 years of age, but was 17.4% for those aged 85 years or more. 120 155 patients (50.2%) underwent revascularisation (STEMI, 72.2%; NSTEMI, 42.1%); 7-year survival exceeded 80% for patients in each group who underwent revascularisation, and was lower than 45% for those who did not. Being older (85 years or older v 18–54 years: adjusted hazard ratio [aHR], 10.6; 95% CI, 10.1–11.1) or a woman (aHR, 1.15; 95% CI, 1.13–1.17) were each associated with greater long term mortality during the study period, as was prior heart failure (aHR, 1.79; 95% CI, 1.76‒1.83). Several non-cardiac conditions and geriatric syndromes common in these patients were independently associated with lower long term survival, including major and metastatic cancer, cirrhosis and end-stage liver disease, and dementia. Conclusion: AMI care in Australia and New Zealand is associated with high rates of long term survival; 7-year rates exceed 80% for patients under 65 years of age and for those who undergo revascularisation. Efforts to further improve survival should target patients with NSTEMI, who are often older and have several comorbid conditions, for whom revascularisation rates are low and survival after AMI poor.

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia, affecting approximately 335 million patients worldwide. Comprehensive pharmacological treatment of AF includes medications for rate or rhythm control and anticoagulants to reduce the risk of thromboembolism; yet, these agents have significant limitations. Oral anti-arrhythmic agents have a slow onset of action, and rapid onset formulations require hospitalization for intravenous therapy. Orally administered drugs also require high doses to attain therapeutic levels, and thus dose-related severe adverse effects are often unavoidable. Given the therapeutic benefits of inhaled drug delivery, including rapid onset of action and very low doses to achieve therapeutic efficacy, this review will discuss the benefits of novel pulmonary delivery of drugs for the management of AF.

Aims Peripheral artery disease (PAD) revascularization can be performed by either endovascular or open surgical approach. Despite increasing use of endovascular revascularization, it is still uncertain which strategy yields better long-term outcomes. Methods and results This retrospective cohort study evaluated patients hospitalized with PAD in Australia and New Zealand who underwent either endovascular or surgical revascularization between 2008 and 2015, and compared procedures using a propensity score-matched analysis. Hybrid interventions were excluded. The primary endpoint was mortality or major adverse limb events (MALE), defined as a composite endpoint of acute limb ischaemia, urgent surgical or endovascular reintervention, or major amputation, up to 8 years post-hospitalization using time-to-event analyses 75 189 patients fulfilled eligibility (15 239 surgery and 59 950 endovascular), from whom 14 339 matched pairs (mean ± SD age 71 ± 12 years, 73% male) with good covariate balance were identified. Endovascular revascularization was associated with an increase in combined MALE or mortality [hazard ratio (HR) 1.13, 95% confidence interval (CI): 1.09–1.17, P < 0.001]. There was a similar risk of MALE (HR 1.04, 95% CI: 0.99–1.10, P = 0.15), and all-cause urgent rehospitalizations (HR 1.01, 95% CI: 0.98–1.04, P = 0.57), but higher mortality (HR 1.16, 95% CI: 1.11–1.21, P < 0.001) when endovascular repair was compared to surgery. In subgroup analysis, these findings were consistent for both claudication and chronic limb-threatening ischaemia presentations. Conclusion Although the long-term risk of MALE was comparable for both approaches, enduring advantages of surgical revascularization included lower long-term mortality. This is at odds with some prior PAD studies and highlights contention in this space.

Objectives The objectives of this study were to compare risk-standardized hospital visit ratios of the predicted to expected number of unplanned hospital visits within 7 days of same-day surgeries performed at US hospital outpatient departments (HOPDs) and to describe the causes of hospital visits. Summary of background data More than half of procedures in the US are performed in outpatient settings, yet little is known about facility-level variation in short-term safety outcomes. Methods The study cohort included 1,135,441 outpatient surgeries performed at 4058 hospitals between October 1, 2015 and September 30, 2016 among Medicare Fee-for-Service beneficiaries aged ≥65 years. Hospital-level, risk-standardized measure scores of unplanned hospital visits (emergency department visits, observation stays, and unplanned inpatient admissions) within 7 days of hospital outpatient surgery were calculated using hierarchical logistic regression modeling that adjusted for age, clinical comorbidities, and surgical procedural complexity. Results Overall, 7.8% of hospital outpatient surgeries were followed by an unplanned hospital visit within 7 days. Many of the leading reasons for unplanned visits were for potentially preventable conditions, such as urinary retention, infection, and pain. We found considerable variation in the risk-standardized ratio score across hospitals. The 203 best-performing HOPDs, at or below the 5th percentile, had at least 22% fewer unplanned hospital visits than expected, whereas the 202 worst-performing HOPDs, at or above the 95th percentile, had at least 29% more post-surgical visits than expected, given their case and surgical procedure mix. Conclusions Many patients experience an unplanned hospital visit within 7 days of hospital outpatient surgery, often for potentially preventable reasons. The observed variation in performance across hospitals suggests opportunities for quality improvement.

Background: Readmissions within 30 days of discharge are prominent among patients with cardiovascular disease. Post hospital syndrome hypothesizes that sleep disturbance during the index admission contributes to an acquired transient vulnerability, leading to increased risk of readmission. This study evaluated the association of in-hospital sleep (a) duration and (b) quality with 30-day all-cause unplanned readmission. Methods: This prospective observational cohort study included patients admitted to the coronary care unit of a South Australian hospital between 2016&ndash, 2018. Study participants were invited to wear an ActiGraph GT3X+ for the duration of their admission and for two weeks post-discharge. Validated sleep and quality of life questionnaires, including the Pittsburgh Sleep Quality Index (PSQI), were administered. Readmission status and questionnaires were assessed at 30 days post-discharge via patient telephone interview and a review of hospital records. Results: The final cohort consisted of 75 patients (readmitted: n = 15, non-readmitted: n = 60), of which 72% were male with a mean age 66.9 &plusmn, 13.1 years. Total sleep time (TST), both in hospital (6.9 &plusmn, 1.3 vs. 6.8 &plusmn, 2.9 h, p = 0.96) and post-discharge (7.4 &plusmn, 1.3 h vs. 8.9 &plusmn, 12.6 h, p = 0.76), was similar in all patients. Patient&rsquo, s perception of sleep, reflected by PSQI scores, was poorer in readmitted patients (9.13 &plusmn, 3.6 vs. 6.4 &plusmn, 4.1, p = 0.02). Conclusions: Although an association between total sleep time and 30-day readmission was not found, patients who reported poorer sleep quality were more likely to be readmitted within 30 days. This study also highlighted the importance of improving sleep, both in and out of the hospital, to improve the outcomes of cardiology inpatients.

Aims Population studies reporting contemporary long-term outcomes following catheter ablation of atrial fibrillation (AF) are sparse. We evaluated long-term clinical outcomes following AF ablation and examined variation in outcomes by age, sex, and the presence of heart failure. Methods and results We identified 30 601 unique patients (mean age 62.7 ± 11.8 years, 30.0% female) undergoing AF ablation from 2008 to 2017 in Australia and New Zealand using nationwide hospitalization data. The primary outcomes were all-cause mortality and rehospitalizations for AF or flutter, repeat AF ablation, and cardioversion. Secondary outcomes were rehospitalizations for other cardiovascular events. During 124 858.7 person-years of follow-up, 1900 patients died (incidence rate 1.5/100 person-years) with a survival probability of 93.0% (95% confidence interval (CI) 92.6–93.4%) by 5 years and 84.0% (95% CI 82.4–85.5%) by 10 years. Rehospitalizations for AF or flutter (13.3/100 person-years), repeat ablation (5.9/100 person-years), and cardioversion (4.5/100 person-years) were common, with respective cumulative incidence of 49.4% (95% CI 48.4–50.4%), 28.1% (95% CI 27.2–29.0%), and 24.4% (95% CI 21.5–27.5%) at 10 years post-ablation. Rehospitalizations for stroke (0.7/100 person-years), heart failure (1.1/100 person-years), acute myocardial infarction (0.4/100 person-years), syncope (0.6/100 person-years), other arrhythmias (2.5/100 person-years), and new cardiac device implantation (2.0/100 person-years) occurred less frequently. Elderly patients and those with comorbid heart failure had worse survival but were less likely to undergo repeat ablation, while long-term outcomes were comparable between the sexes. Conclusion Patients undergoing AF ablations had good long-term survival, a low incidence of rehospitalizations for stroke or heart failure, and about half remained free of rehospitalizations for AF or flutter, including for repeat AF ablation, or cardioversion.

Contemporary long-term survival following a heart failure (HF) hospitalization is uncertain. We evaluated survival up to 10 years after a HF hospitalization using national data from Australia and New Zealand, identified predictors of survival, and estimated the attributable loss in life expectancy.Patients hospitalized with a primary diagnosis of HF from 2008-2017 were identified and all-cause mortality assessed by linking with Death Registries. Flexible parametric survival models were used to estimate survival, predictors of survival and loss in life expectancy. A total of 283 048 patients with HF were included (mean age 78.2 ± 12.3 years, 50.8% male). Of these, 48.3% (48.1-48.5) were surviving by 3 years, 34.1% (33.9-34.3) by 5 years and 17.1% (16.8-17.4) by 10 years (median survival 2.8 years). Survival declined with age with 53.4% of patients aged 18-54 years and 6.2% aged ≥85 years alive by 10 years (adjusted hazard ratio [aHR] for mortality 4.84, 95% confidence interval [CI] 4.65-5.04 for ≥85 years vs. 18-54 years) and was worse in male patients (aHR 1.14, 95% CI 1.13-1.15). Prior HF (aHR 1.20, 95% CI 1.18-1.22), valvular and rheumatic heart disease (aHR 1.11, 95% CI 1.10-1.13) and vascular disease (aHR 1.07, 95% CI 1.04-1.09) were cardiovascular comorbidities most strongly associated with long-term death. Non-cardiovascular comorbidities and geriatric syndromes were common and associated with higher mortality. Compared with the general population, HF was associated with a loss of 7.3 years in life expectancy (or 56.6% of the expected life expectancy) and reached 20.5 years for those aged 18-54 years.Less than one in five patients hospitalized for HF were surviving by 10 years with patients experiencing almost 60% loss in life expectancy compared with the general population, highlighting the considerable persisting societal burden of HF. Concerted multidisciplinary efforts are needed to improve post-hospitalization outcomes of HF.

Background: Data on long-term outcomes following an acute stroke are sparse. We assessed survival, risk of recurrent stroke and loss in life expectancy following an acute stroke using population-wide data from Australia and New Zealand. Methods: We included all adults with the first stroke hospitalization during 2008 and 2017 at all public and most private hospitals. Patients were followed up to 10 years after the stroke by linkage to each region’s Registry of Deaths and subsequent hospitalizations. Flexible parametric survival modeling was used to estimate all-cause mortality, stroke recurrence, and loss in life expectancy. Competing risk model was used when estimating the risk of stroke recurrence. Results: Three hundred thirteen thousand one hundred sixty-two patients were included (mean age 73.0±14.6 y, 52.0% males) with ischemic stroke (175 547, 56.1%) being the most common, followed by hemorrhagic stroke (77 940, 24.9%) and unspecified stroke (59 675, 19.1%). The overall survival probability was 79.4% at 3 months, 73.0% at 1 year, 52.8% at 5 years, and 36.4% at 10 years. Cumulative incidence of stroke recurrence was 7.8% at 3 months, 11.0% at 1 year, 19.8% at 5 years, and 26.8% at 10 years. Hemorrhagic stroke was associated with greater mortality (hazard ratio, 2.02 [95% CI, 1.99–2.04]) and recurrent stroke (hazard ratio, 1.63 [95% CI, 1.59–1.67]) compared with ischemic stroke. Female sex (hazard ratio, 1.10 [95% CI, 1.09–1.11]) and increasing age (≥85 years versus 18–54 years: hazard ratio, 7.36 [95% CI, 7.15–7.57]) were also associated with increased mortality. Several risk factors including atherosclerotic coronary and noncoronary vascular disease, cardiac arrhythmia, and diabetes were associated with increased risk of mortality and recurrent stroke. Compared with the general population, an acute stroke was associated with a loss of 5.5 years of life expectancy, or 32.7% of the predicted life expectancy, and was pronounced in patients with a hemorrhagic stroke (7.4 years and 38.5% of predicted life expectancy lost). Conclusions: In this population-wide study, death and recurrence of stroke were common after an acute stroke and an acute stroke was associated with considerable loss in life expectancy. Further improvements in treatment and secondary prevention of stroke are needed to reduce these risks.

Introduction: Cardiac complications of COVID-19 include acute cardiac injury, myopericarditis, cardiomyopathy and arrhythmias. This study aimed to describe the incidence of cardiac complications in patients admitted to hospital with COVID-19 in Australia. Methods: AUS-COVID is a multicentre observational cohort study across 21 Australian hospitals including all index hospitalisations with laboratory-proven COVID-19 in patients aged 18 years or older. All consecutive patients entered in the AUS-COVID Registry by 28 th January 2021 were included in the present study. Results: Six hundred and forty-four hospitalised patients (62.5 ± 20.1 years old, 51.1% male) with COVID-19 were enrolled in the study. Overall in-hospital mortality was 14.3%. Twenty (3.6%) patients developed new atrial fibrillation or flutter during admission and 9 (1.6%) patients were diagnosed with new heart failure or cardiomyopathy. Three (0.5%) patients developed high grade atrioventricular (AV) block. Two (0.3%) patients were clinically diagnosed with pericarditis or myopericarditis. Among the 295 (45.8%) patients with at least one troponin measurement, 99 (33.6%) had a peak troponin above the upper limit of normal (ULN). In-hospital mortality was higher in patients with raised troponin (32.3% vs 6.1%, p Conclusions: Among patients with COVID-19 requiring hospitalisation in Australia, troponin elevation was common but clinical cardiac sequelae were uncommon. The incidence of atrial arrhythmias and troponin elevation was greatest in patients 65 years and older. Trial registration: AUS-COVID. ACTRN12620000486921. http://www.anzctr.org.au/

Background: Complications following catheter ablation of atrial fibrillation (AF) have been extensively examined but little is known about their associated economic burden. Hypothesis: Complications of AF ablations were associated with a significant increase in healthcare resources utilization. Methods: All patients >18 years undergoing AF ablations in the financial years of 2011-2017 in Australia with available cost data from the National Hospital Cost Data Collection were included. The primary outcome was occurrence of any complications up to 30-days post-discharge. All costs were adjusted to 2021 Australian dollars. The increase in length of stay (LOS) and in cost associated with complications, adjusting for patient characteristics, was evaluated using generalized linear models and negative binomial regression. Results: Our study included 19,916 patients (mean age 62.6±11.3 years, 30.2% females). The median length of stay was 1 day (interquartile range [IQR] 1-2 days) and the median cost per hospitalization was $6,646.5 (IQR $5,979.7-$10,210.5). A total of 1,074 patients (5.39%) experienced a complication (4.24% during the hospital stay and 1.37% post-discharge). The most common complications were bleeding (3.18%), pericardial effusion (0.66%), and vascular injury (0.43%). On average, the occurrence of a complication was associated with 2.8 excess bed-days and a $6,119.4 (95%CI $5,491.2-$6,747.7) increase in hospitalization cost (totaling nearly $6.6 millions). Complications that required cardiac surgery were associated with the highest incremental cost per patient ($19,958.5 [95%CI $17,304.5-$22,612.6]) but most of excess cost was attributable to bleeding ($4,808.5 per patient, $3,048,596.1 in total, 44.4% of total excess cost) and pericardial effusion ($6,064.8 per patient, $1,073,094.9 in total, 16.3% of total excess cost). Conclusions: The occurrence of any complication following AF ablation is associated with a significant economic burden, most of which was attributable to bleeding and pericardial effusion. Strategies to improve procedural safety and reduce healthcare cost should focus on these complications.

Introduction: To assess whether hypertension is an independent risk factor for mortality amongst patients hospitalised with COVID-19 and to evaluate the impact of angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) on mortality in patients with a background of hypertension. Methods: This observational cohort study included all consecutive index hospitalisations with laboratory proven COVID-19 aged 18 years or older across 21 Australian hospitals entered in the AUS-COVID Registry by 22nd January 2021. Patients were excluded if their past medical or medication history was not available or if they were transferred to another hospital in which case mortality outcomes were not available. Registry data were analysed for in-hospital mortality in patients with comorbidities including hypertension, and baseline treatment with ACE inhibitors or ARBs. Results: 546 consecutive patients (62.9±19.8 years old, 51.8% male) hospitalised with COVID-19 were enrolled. In the multivariable model, significant predictors of mortality were age (aOR 1.09, 95% CI 1.07-1.12, p Conclusions: In patients hospitalised with COVID-19, pre-existing hypertension was the most prevalent comorbidity but was not independently associated with mortality. Similarly, the baseline use of ACE inhibitors or ARBs had no independent association with in-hospital mortality.

Aims Urinary sodium concentration (UNa) is a simple test advocated to assess diuretics efficacy and predict outcomes in acute heart failure (AHF). We performed a systematic review and meta-analysis to examine the association of UNa with outcomes of AHF. Methods and results We searched Embase and Medline for eligible studies that reported the association between UNa and outcomes of urinary output, weight loss, worsening renal function, length of hospital stay, re-hospitalization, worsening heart failure, and all-cause mortality in AHF. Nineteen observational studies out of 1592 screened records were included. For meta-analyses of outcomes, we grouped patients into high vs. low UNa, with most studies defining high UNa as >48–65 mmol/L. In the high UNa group, pooled data showed a higher urinary output (mean difference 502 mL, 95% CI 323–681, P < 0.01), greater weight loss (mean difference 1.6 kg, 95% CI 0.3–2.9, P = 0.01), and a shorter length of stay (mean difference −1.4 days, 95% CI −2.8 to −0.1, P = 0.03). There was no significant difference in worsening kidney function (OR 0.54, 95% CI 0.25–1.16, P = 0.1). Due to the small number of studies, we did not report pooled estimates for re-hospitalization and worsening heart failure. High UNa was associated with lower odds of 30-day (OR 0.27; 95% CI 0.14–0.49, P < 0.01), 90-day (OR 0.39,95% CI 0.25–0.59, P < 0.01) and 12-month (OR 0.35; 95% CI 0.20–0.61, P < 0.01) mortality. Conclusion High UNa after diuretic administration is associated with higher urinary output, greater weight loss, shorter length of stay, and lower odds of death. UNa is a promising marker of diuretic efficacy in AHF which should be confirmed in randomized trials.

Atrial fibrillation (AF) is a leading cause of hospitalisations, yet little is known about 30-day readmissions following discharge despite increasing policy focus on reducing readmissions. We assessed the rate, timing, causes and predictors of 30-day unplanned readmission following an acute and elective AF hospitalisation using population-wide data.We studied all patients hospitalised for AF from 2010 to 2015 at all public and most private hospitals in Australia and New Zealand. The main outcome measures were unplanned readmissions within 30 days of discharge, primary diagnosis associated with these readmissions, and their predictors as modelled by logistic regression.Among 301,654 patients hospitalised for AF (mean age 69.2±13.6 yrs, 55.6% female, 65.2% acute presentations), 29,750 (9.9%) experienced an unplanned readmission within 30 days with 62.6% occurring by 14 days. Unplanned readmissions occurred more frequently following an acute versus elective AF hospitalisations (12.5% vs 4.9%, p0.001). The most common diagnoses associated with readmissions were recurrence of AF (n=9,890, 33.2%), and preventable conditions including heart failure (n=2,683, 9.0%), pneumonia (n=724, 2.4%) and acute myocardial infarction (n=510, 1.7%). A higher risk of 30-day readmission was associated with congenital cardiac/circulatory defect (OR 2.18, CI 1.44-3.30), congestive heart failure (OR 1.34, CI 1.30-1.39), and arrhythmia/conduction disorders (OR 1.25, CI 1.21-1.28).Almost 1 in 10 AF hospitalisations resulted in unplanned readmission within 30-days, mostly for AF recurrence. Improved clinical management of AF and transitional care planning are required to reduce unplanned readmissions following AF hospitalisations.

Aims Recent US studies report rising rates of mortality and in-hospital complications following catheter ablation of atrial fibrillation (AF), but whether this is a global phenomenon is uncertain. The aim of this study was to examine trends in 30-day mortality and complications following AF ablation in Australia and New Zealand (ANZ) from 2008 to 2017. Methods and results We identified 37 243 AF (mean age 62.4 ± 11.5 years, 29.6% females, 94.5% elective procedures) ablations using national hospitalization data. The primary outcome was occurrence of any complication, including all-cause mortality, within 30 days of discharge. Trends were evaluated using logistic regression adjusting for changes in patient characteristics. The annual number of ablations increased from 1359 (2008) to 5115 (2017). Patients’ age and rates of heart failure (9.8–10.6%), diabetes (6.8–12.4%), and chronic kidney disease (2.2–4.1%) also increased over time. From 2008 to 2017, the overall rate of complications declined from 7.51% to 5.04% [adjusted odds ratio (aOR) 0.96 (95% confidence interval, CI, 0.94–0.97)/year]. Rates of pericardial effusion [1.69–0.70%, aOR 0.93 (0.89–0.97)], bleeding [4.49–2.74%, aOR 0.94 (0.92–0.96)], and vascular injury [0.52–0.16%, aOR 0.91 (0.85–0.98)] declined, but rates of acute kidney injury [0.15–0.68%, aOR 1.16 (1.08–1.25)] and infection [0.15–0.57%, aOR 1.07 (1.01–1.14)] increased over time. The overall 30-day mortality rate was low (0.11%) and unchanged [0.00–0.16%, aOR 0.99 (0.88–1.11)]. Conclusion Despite a five-fold increase in AF ablations and the rising risk profile of patients, complications following AF ablation declined by 30% from 2008 to 2017 in ANZ. Procedure-related death was uncommon and occurred in less than 1 in 850 patients.

Background Atrial fibrillation/atrial flutter (AF/AFL) hospitalisations are common, however, little is known about the long-term outcomes of these episodes. Objective To examine the incidence of mortality, all-cause and cause-specific re-hospitalisations at up to 8 years after a hospitalisation for AF/AFL. Methods Unique patients hospitalised with a primary diagnosis of AF/AFL from 2008–2015 were identified using nation-wide hospitalisation data from Australia and New Zealand. All-cause mortality was the primary outcome. Secondary endpoints included all-cause and cause-specific re-hospitalisations. Results were reported as incident rate per 100 patient-years. Results We included 265,737 patients (mean age 69.9±13.9y, female 45.2%, elective 28.7%). The median length of stay was 1 day (Interquartile range [IQR] 0–4 days) and the median CHA2DS2-VASc score was 2 (IQR 1–2). During the index hospitalisation, 9,837 (3.7%) patients underwent catheter or surgical ablation and 52,634 (19.8%) underwent cardioversion. During the median follow-up time of 3.4 years (range 0–8.0 years), 53,669 patients died (incident rate of 5.7/100 patient-years) with a survival probability gradually decreasing from 92.8% (95% CI 92.7–92.9%) at 1-year to 65.4% (95% CI 64.9–65.8%) at 8-years post-discharge (Table 1 and Figure 1). All-cause re-hospitalisations occurred in 210,118 patients (incident rate of 22.2/100 patient-years) with a rehospitalisation-free survival probability of 7.1% (95% CI 6.9—7.3%) at the end of follow-up. Unplanned re-hospitalisations occurred more frequently than planned episodes (incident rate of 17.2 vs. 16.6/100 patient-years respectively). AF/AFL accounted for 25.1% of all-cause re-hospitalisations (incident rate of 8.9/100 patient-years) and the probability of freedom from re-hospitalisations for AF/AFL was 55.4% (95% CI 55.0–55.8%) at 8-years. Incident rates of re-hospitalisations for catheter ablation (1.5/100 patient-years), stroke (1.6/100 patient-years), heart failure (2.7/100 patient-years), and acute myocardial infarction (1.0/100 patient-years) were low. In subgroup analyses, worse survival was observed in female patients, older age groups, patients with comorbid heart failure, hypertension, diabetes, and those who did not undergo ablation during the index hospitalisation. Conclusion Nearly two-thirds of patients were surviving by 8-years following an AF/AFL hospitalisation with a low rate of re-hospitalisations for stroke, heart failure, and myocardial infarction. However, re-hospitalisations for recurrent atrial arrhythmia were common. Efforts to reduce re-hospitalisations, especially unplanned encounters, are required to improve patient outcomes. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): National Heart Foundation of Australia

Background Over the past 2 decades, guidelines for digoxin use have changed significantly. However, little is known about the national-level trends of digoxin use, hospitalizations for toxicity, and subsequent outcomes over this time period. Methods To describe digoxin prescription trends, we conducted a population-level, cohort study using data from IQVIA, Inc.’s National Prescription Audit (2007-2014) for patients aged ≥ 65 years. Further, in a national cohort of Medicare fee-for-service beneficiaries aged ≥ 65 years in the United States, we assessed temporal trends of hospitalizations associated with digoxin toxicity and the outcomes of these hospitalizations between 1999 and 2013. Results From 2007 through 2014, the number of digoxin prescriptions dispensed decreased by 46.4%; from 8,099,856 to 4,343,735. From 1999 through 2013, the rate of hospitalizations with a principal or secondary diagnosis of digoxin toxicity decreased from 15 to 2 per 100,000 person-years among Medicare fee-for-service beneficiaries. In-hospital and 30-day mortality rates associated with hospitalization for digoxin toxicity decreased significantly among Medicare fee-for-service beneficiaries; from 6.0% (95% confidence interval [CI], 5.2-6.8) to 3.7% (95% CI, 2.2-5.7) and from 14.0% (95% CI, 13.0-15.2) to 10.1% (95% CI, 7.6-13.0), respectively. Rates of 30-day readmission for digoxin toxicity decreased from 23.5% (95% CI, 22.1-24.9) in 1999 to 21.7% (95% CI, 18.0-25.4) in 2013 (P Conclusion While digoxin prescriptions have decreased, it is still widely prescribed. However, the rate of hospitalizations for digoxin toxicity and adverse outcomes associated with these hospitalizations have decreased. These findings reflect the changing clinical practice of digoxin use, aligned with the changes in clinical guidelines.

OBJECTIVES: Describe the incidence of cardiac complications in patients admitted to hospital with COVID-19 in Australia. DESIGN: Observational cohort study. SETTING: Twenty-one (21) Australian hospitals. PARTICIPANTS: Consecutive patients aged ≥18 years admitted to hospital with laboratory confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. MAIN OUTCOME MEASURES: Incidence of cardiac complications. RESULTS: Six-hundred-and-forty-four (644) hospitalised patients (62.5±20.1 yo, 51.1% male) with COVID-19 were enrolled in the study. Overall in-hospital mortality was 14.3%. Twenty (20) (3.6%) patients developed new atrial fibrillation or flutter during admission and 9 (1.6%) patients were diagnosed with new heart failure or cardiomyopathy. Three (3) (0.5%) patients developed high grade atrioventricular (AV) block. Two (2) (0.3%) patients were clinically diagnosed with pericarditis or myopericarditis. Among the 295 (45.8%) patients with at least one troponin measurement, 99 (33.6%) had a peak troponin above the upper limit of normal (ULN). In-hospital mortality was higher in patients with raised troponin (32.3% vs 6.1%, p

Pre-hospital activation and direct cardiac catheterisation laboratory (CCL) transfer of ST segment elevation myocardial infarction (STEMI) has previously been shown to improve door-to-balloon (DTB) times yet there is limited outcome data in the Australian context. We aimed to assess the impact of pre-hospital activation on STEMI performance measures and mortality.Prospective cohort study of consecutive ambulance transported STEMI patients treated with primary percutaneous coronary intervention (PCI) patients over a 10-year period (1 January 2008-31 December 2017) at The Prince Charles Hospital, a large quaternary referral centre in Brisbane, Queensland Australia. Comparisons were performed between patients who underwent pre-hospital CCL activation and patients who did not. STEMI performance measures, 30-day and 1-year mortality were examined.Amongst 1,009 patients included (mean age: 62.8 yrs±12.6), pre-hospital activation increased over time (26.6% in 2008 to 75.0% in 2017, p0.001). Median DTB time (35 mins vs 76 mins p0.001) and percentage meeting targets (DTB60 mins 92% vs 27%, p0.001) improved significantly with pre-hospital activation. Pre-hospital activation was associated with significantly lower 30-day (1.0% vs 3.5%, p=0.007) and 1-year (1.2% vs 7.7%, p0.001) mortality. After adjusting for confounders and mediators, we observed a strong total effect of pre-hospital activation on 1-year mortality (OR 5.3, 95%CI 2.2-12.4, p0.001) compared to patients who did not have pre-hospital activation. False positive rates were 3.7% with pre-hospital activation.In patients who underwent primary PCI for STEMI, pre-hospital activation and direct CCL transfer is associated with low false positive rates, significantly reduced time to reperfusion and lower 30-day and 1-year mortality.

Background Leadless pacemaker is a novel technology, and evidence supporting its use is uncertain. We performed a systematic review and meta‐analysis to examine the safety and efficacy of leadless pacemakers implanted in the right ventricle. Methods and Results We searched PubMed and Embase for studies published before June 6, 2020. The primary safety outcome was major complications, whereas the primary efficacy end point was acceptable pacing capture threshold (≤2 V). Pooled estimates were calculated using the Freedman‐Tukey double arcsine transformation. Of 1281 records screened, we identified 36 observational studies of Nanostim and Micra leadless pacemakers, with most (69.4%) reporting outcomes for the Micra. For Micra, the pooled incidence of complications at 90 days (n=1608) was 0.46% (95% CI, 0.08%–1.05%) and at 1 year (n=3194) was 1.77% (95% CI, 0.76%–3.07%). In 5 studies with up to 1‐year follow‐up, Micra was associated with 51% lower odds of complications compared with transvenous pacemakers (3.30% versus 7.43%; odds ratio [OR], 0.49; 95% CI, 0.34–0.70). At 1 year, 98.96% (95% CI, 97.26%–99.94%) of 1376 patients implanted with Micra had good pacing capture thresholds. For Nanostim, the reported complication incidence ranged from 6.06% to 23.54% at 90 days and 5.33% to 6.67% at 1 year, with 90% to 100% having good pacing capture thresholds at 1 year (pooled result not estimated because of the low number of studies). Conclusions Most studies report outcomes for the Micra, which is associated with a low risk of complications and good electrical performance up to 1‐year after implantation. Further data from randomized controlled trials are needed to support the widespread adoption of these devices in clinical practice.

Structured AbstractObjectivesWe sought to assess the rate of unplanned hospital visits among patients undergoing ambulatory surgery.Summary Background DataThe majority of surgeries performed in the United States now take place in outpatient settings. Post-discharge hospital visit rates have been shown to vary widely, suggesting variation in surgical or discharge care quality. Complicating efforts to address quality, most facilities and surgeons are unaware of their patients’ hospital visits after surgery since patients may present to a different hospital.MethodsWe used state-level, administrative data from the Agency for Healthcare Research and Quality’s Healthcare Cost and Utilization Project from California to assess unplanned hospital visits after ambulatory surgery. To compare rates across centers, we determined the age, sex, and procedure-adjusted rates of hospital visits for each facility using 2-level, hierarchical, generalized linear models using methods similar to existing Centers for Medicare and Medicaid Services measures.ResultsAmong a total of 1,260,619 ambulatory same-day surgeries from 440 surgical facilities, the risk adjusted 30-day rate of unplanned hospital visits was 4.8%, with emergency department visits of 3.1% and hospital admissions of 1.7%. Several patient characteristics were associated with increased risk of unplanned hospitals visits, including increased age, increased number of comorbidities (using the Elixhauser score), and type of procedure (pConclusionsThe overall rate unplanned hospital visits within 30 days after same-day surgery is low but variable, suggesting a difference in the quality of care provided. Further, these rates are higher among specific patient populations and procedure types, suggesting areas for targeted improvement.Mini-AbstractThe majority of surgeries performed in the United States now take place in outpatient settings with wide variation of post-discharge hospital visit rates. We used state-level, administrative data to assess the rate of unplanned hospital visits after ambulatory surgery and found a risk adjusted 30-day rate of 4.8%. Increased age, increased number of comorbidities (using the Elixhauser score), and type of procedure were associated with increased risk of unplanned hospitals visits, suggesting areas for targeted improvement.

Aims Population studies that provide unbiased estimates of gender differences in risk of complications following catheter ablation of atrial fibrillation (AF) are sparse. We sought to evaluate the association of female gender and risk of complications following AF ablation in a nationwide cohort. Methods and results We identified 35 211 patients (29.5% females) undergoing AF ablations from 2008 to 2017 using national hospitalization data from Australia and New Zealand. The primary outcome was any procedural complication occurring up to 30-days after discharge. Logistic regression was used to adjust for differences in baseline characteristics between sexes. Compared with males, females were older (mean age 64.9 vs. 61.2 years), had higher rates of hypertension (14.0% vs. 11.6%) and haematological disorders (5.3% vs. 3.8%) and experienced a higher rate of procedural complications (6.96% vs. 5.41%) (all P Conclusion Females undergoing AF ablations experienced a 25% higher risk of procedural complications compared with males, a disparity that has persisted over time despite a falling complication rate. Efforts to reduce this gender disparity should focus on reducing the incidence of pericardial effusion, pericarditis, vascular injury, and bleeding.

Thirty-day mortality following coronary artery bypass grafting (CABG) is a widely accepted marker for quality of care. Although surgical mortality has declined, the utility of this measure to profile quality has not been questioned. We assessed the institutional variation in risk-standardised mortality rates (RSMR) following isolated CABG within Australia and New Zealand (ANZ).We used an administrative dataset from all public and most private hospitals across ANZ to capture all isolated CABG procedures recorded between 2010 and 2015. The primary outcome was all-cause death occurring in-hospital or within 30-days of discharge. Hospital-specific RSMRs and 95% CI were estimated using a hierarchical generalised linear model accounting for differences in patient characteristics.Overall, 60,953 patients (mean age 66.1 ± 10.1y, 18.7% female) underwent an isolated CABG across 47 hospitals. The observed early mortality rate was 1.69% (n = 1029) with 81.8% of deaths recorded in-hospital. The risk-adjustment model was developed with good discrimination (C-statistic = 0.81). Following risk-adjustment, a 3.9-fold variation was observed in RSMRs among hospitals (median:1.72%, range:0.84-3.29%). Four hospitals had RSMRs significantly higher than average, and one hospital had RSMR lower than average. When in-hospital mortality alone was considered, the median in-hospital RSMR was 1.40% with a 5.6-fold variation across institutions (range:0.57-3.19%).Average mortality following isolated CABG is low across ANZ. Nevertheless, in-hospital and 30-day mortality vary among hospitals, highlighting potential disparities in care quality and the enduring usefulness of 30-day mortality as an outcome measure. Clinical and policy interventions, including participating in clinical quality registries, are needed to standardise CABG care.

Introduction: The subcutaneous (S-) implantable cardioverter defibrillator (ICD) is an alternative to the transvenous (TV-) ICD that is increasingly implanted in younger patients. However, data on the safety and effectiveness of the S-ICD in older patients are lacking. Methods: We compared S-ICD and single chamber TV-ICD implants in Medicare beneficiaries (≥65yrs) using National Cardiovascular Data Registry ICD Registry data from 9/28/2012 through 12/31/2017. We excluded patients with prior pacemaker or ICD, an indication for pacing or resynchronization, and those undergoing implant in an acute setting. Mortality status was determined using the Medicare master summary beneficiary file. Cox regression analyses with overlap weights were used to compare all-cause mortality. Mean cumulative counts of all-cause readmissions were compared among for Fee for Service beneficiaries. Results: A total of 23,717 patients met inclusion criteria [mean age 72.7±5.8 years, 29% female, 69% ischemic heart disease, 33% atrial arrhythmias, 49% NYHA II, 31.7% NYHA III, ejection fraction (EF) 28±9%, 3% dialysis dependent, 20% with prior ventricular tachycardia]. Compared to TV-ICD patients (n=22,264), S-ICD patients (n=1,453, 6% overall) were more often male, black, diabetic, dialysis dependent and were less likely to have atrial or ventricular arrhythmias or ischemic heart disease. There was no difference in age or EF between the 2 groups. In adjusted analyses, during a median follow-up of 2.3 years (IQR: 1.2 - 3.5), there was no difference between the 2 groups in all-cause mortality (HR 1.04, CI 0.91-1.17, Figure A ) or readmissions (based on overlap of confidence intervals, Figure B ). Conclusions: In a large representative cohort of older patients undergoing ICD implant, all-cause mortality and readmission were similar among S-ICD and TV-ICD recipients. These findings support use of the S-ICD for the prevention of sudden cardiac death in appropriately selected older patients.

Background Comparing outcomes of care between public and private hospitals is critical to inform patients and improve care quality. Purpose To compare complication rates following catheter ablation of atrial fibrillation (AF) up to 30-days post discharge between public and private hospitals. Methods We included patients ≥18 years who underwent AF ablation in the Australian states of New South Wales, Queensland, Victoria, and Western Australia from 2010–2015. The primary outcome was the occurrence of any complication up to 30-days after discharge. The association between provider type and the risk of complications was examined using logistic regression with inverse probability of treatment weighting (IPTW) propensity scores to account for differences in measured confounders. The minimum strength of association required for an unmeasured confounder to nullify any observed association was estimated using the E value. Results We identified 18,074 AF ablations during the study period (mean age 62.3±11.4y, 28.8% female, 78.4% performed in private hospitals). Patients ablated at public hospitals were younger (59.3 vs. 63.1y, p Conclusion AF ablation at a public hospital was associated with a 46% higher risk of complications compared with ablation at a private hospital, mainly driven by a higher risk of complications requiring cardiac surgery, acute kidney injury, cardiorespiratory failure, infections, and bleeding. The disparity could be due to differences in care quality between two sectors or explained by unmeasured confounders such as higher procedural complexity in public hospitals. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): The National Heart Foundation of Australia

Background Recent studies from the United States report rising rates of in-hospital complications and mortality following catheter ablation of atrial fibrillation (AF) but whether such a trend is observed in other populations is uncertain. Purpose To examine the trends in complications and mortality following AF ablations up to 30 days after discharge in Australia and New Zealand (ANZ) using nationwide data. Methods All patients ≥18y undergoing catheter ablation of AF from 2010–2015 were identified using hospitalisation data from all public and most private hospitals in ANZ. The primary endpoint was one or more procedural complications during the hospital stay or within 30 days of discharge. The secondary endpoints were mortality and other specific complications. Unadjusted trend was evaluated using Cochran-Armitage test while that of complications, adjusting for differences in other characteristics, was evaluated using multivariate logistic regression with the year of ablation modelled as a continuous variable. Results are reported as odd ratios (OR) and 95% confidence intervals (CI). Results A total of 22,582 AF ablations were included (mean age 62.2±11.6y, 29.1% female, 94.4% elective procedures). The number of ablations increased by 26.4% during the study period (3,097 in 2010 to 3,915 in 2015). Rates of heart failure (8.98% to 10.09%, p for trend=0.010), diabetes (4.52% to 12.46%, p Conclusions Though more patients with heart failure, diabetes and chronic kidney disease underwent catheter ablation of AF over time in ANZ, the overall complication rate was unchanged with a significant decrease in the incidences of major bleeding and venous thromboembolism. However, rate of acute kidney injury nearly doubled, and this could be a potential target for efforts to further improve procedural safety. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): The National Heart Foundation of Australia

IntroductionDespite global concerns about the safety and quality of health care, population-wide studies of hospital outcomes are uncommon. The SAFety, Effectiveness of care and Resource use among Australian Hospitals (SAFER Hospitals) study seeks to estimate the incidence of serious adverse events, mortality, unplanned rehospitalisations and direct costs following hospital encounters using nationwide data, and to assess the variation and trends in these outcomes.Methods and analysisSAFER Hospitals is a cohort study with retrospective and prospective components. The retrospective component uses data from 2012 to 2018 on all hospitalised patients age ≥18 years included in each State and Territories’ Admitted Patient Collections. These routinely collected datasets record every hospital encounter from all public and most private hospitals using a standardised set of variables including patient demographics, primary and secondary diagnoses, procedures and patient status at discharge. The study outcomes are deaths, adverse events, readmissions and emergency care visits. Hospitalisation data will be linked to subsequent hospitalisations and each region’s Emergency Department Data Collections and Death Registries to assess readmissions, emergency care encounters and deaths after discharge. Direct hospital costs associated with adverse outcomes will be estimated using data from the National Cost Data Collection. Variation in these outcomes among hospitals will be assessed adjusting for differences in hospitals’ case-mix. The prospective component of the study will evaluate the temporal change in outcomes every 4 years from 2019 until 2030.Ethics and disseminationHuman Research Ethics Committees of the respective Australian states and territories provided ethical approval to conduct this study. A waiver of informed consent was granted for the use of de-identified patient data. Study findings will be disseminated via presentations at conferences and publications in peer-reviewed journals.