Estimating the economic impact of acute coronary syndrome in New Zealand over time (ANZACS-QI 64): a national registry-based cost burden study.

OBJECTIVES: To estimate the changes in costs associated with acute coronary syndrome (ACS) admissions in New Zealand (NZ) public hospitals over a 12-year period. DESIGN: A cost-burden study of ACS in NZ was conducted from the NZ healthcare system perspective. SETTING: Hospital admission costs were estimated using relevant diagnosis-related groups and their costs for publicly funded casemix hospitalisations, and applied to 190 364 patients with ACS admitted to NZ public hospitals between 2007 and 2018 identified from routine national hospital datasets. Trends in the costs of index ACS hospitalisation, hospital admissions costs, coronary revascularisation and all-cause mortality up to 1 year were evaluated. All costs were presented as 2019 NZ dollars. PRIMARY OUTCOME MEASURES: Healthcare costs attributed to ACS admissions in NZ over time. RESULTS: Between 2007 and 2018, there was a 42% decrease in costs attributed to ACS (NZ$7.7 million (M) to NZ$4.4 M per 100 000 per year), representing a decrease of NZ$298 827 per 100 000 population per year. Mean admission costs associated with each admission declined from NZ$18 411 in 2007 to NZ$16 898 over this period (p<0.001) after adjustment for key clinical and procedural characteristics. These reductions were against a background of increased use of coronary revascularisation (23.1% (2007) to 38.1% (2018)), declining ACS admissions (366-252 per 100 000 population) and an improvement in 1-year survival post-ACS. Nevertheless, the total ACS cost burden remained considerable at NZ$237 M in 2018. CONCLUSIONS: The economic cost of hospitalisations for ACS in NZ decreased considerably over time. Further studies are warranted to explore the association between reductions in ACS cost burden and changes in the management of ACS.

Data Resource: Vascular Risk in Adult New Zealanders (VARIANZ) datasets.

INTRODUCTION: The Vascular Risk in Adult New Zealanders (VARIANZ) datasets contain a range of routinely-collected New Zealand health data relevant to cardiovascular disease (CVD) and related conditions. The datasets enable exploration of cardiovascular-related treatment, service utilisation, outcomes and prognosis. PROCESSES: Each dataset is constructed by anonymised individual-level linkage of eight national administrative health databases to identify all New Zealand adults aged ≥20 years who have recorded contact with publicly-funded New Zealand health services during a given year from 2006 onwards, when data quality is considered sufficient. DATA CONTENTS: Individual-level data for each VARIANZ dataset can include variables covering demography, dispensing of cardiovascular disease (CVD) preventive medications and prior hospitalisations for atherosclerotic CVD, heart failure, atrial fibrillation and diabetes. If required, VARIANZ datasets can be individually linked to follow-up national routinely collected health data in subsequent years, including all-cause mortality events and fatal/non-fatal CVD events, to create VARIANZ longitudinal cohorts. Bespoke linkage can also be undertaken to include other national and regional administrative health data such as non-CVD related hospitalisations in order to explore CVD comorbidities or novel risk factors. Furthermore, a subset of the VARIANZ datasets based on specific health contacts (such as CVD hospitalisations only) can also be identified, and some data can be requested for years prior to 2006. The New Zealand routinely-collected health databases used to construct the VARIANZ datasets do not capture primary care diagnostic classifications or certain CVD risk factor data such as smoking status, blood pressure or lipid profiles. CONCLUSION: The Vascular Risk in Adult New Zealanders (VARIANZ) datasets capture the majority of the New Zealand population in a given year and are available from 2006 onwards, or earlier than 2006 for some datasets based on specific health contacts. VARIANZ data can be used to explore a range of research questions regarding management, outcomes and prognosis for CVD.

Pacemaker Use in New Zealand - Data From the New Zealand Implanted Cardiac Device Registry (ANZACS-QI 15).

BACKGROUND: The New Zealand Cardiac Implanted Device Registry (Device) has recently been developed under the auspices of the New Zealand Branch of the Cardiac Society of Australia and New Zealand. This study describes the initial Device registry cohort of patients receiving a new pacemaker, their indications for pacing and their perioperative complications. METHODS: The Device Registry was used to audit patients receiving a first pacemaker between 1st January 2014 and 1st June 2015. RESULTS: We examined 1611 patients undergoing first pacemaker implantation. Patients were predominantly male (59%), and had a median age of 70 years. The most common symptom for pacemaker implantation was syncope (39%), followed by dizziness (30%) and dyspnoea (12%). The most common aetiology for a pacemaker was a conduction tissue disorder (35%), followed by sinus node dysfunction (22%). Atrioventricular (AV) block was the most common ECG abnormality, present in 44%. Dual chamber pacemakers were most common (62%), followed by single chamber ventricular pacemakers (34%), and cardiac resynchronisation therapy - pacemakers (CRT-P) (2%). Complications within 24hours of the implant procedure were reported in 64 patients (3.9%), none of which were fatal. The most common complication was the need for reoperation to manipulate a lead, occurring in 23 patients (1.4%). CONCLUSION: This is the first description of data entered into the Device registry. Patients receiving a pacemaker were younger than in European registries, and there was a low use of CRT-P devices compared to international rates. Complications rates were low and compare favourably to available international data.

Variation in Arterial Access for Invasive Coronary Procedures in New Zealand: A National Analysis (ANZACS-QI 5).

BACKGROUND: Radial arterial access (RA) and femoral arterial access (FA) rates for invasive coronary angiography (ICA) vary widely internationally. The European Society of Cardiology (ESC) suggests default RA is feasible. We aim to investigate the variation in RA rates across all New Zealand public hospitals. METHODS AND RESULTS: Patient characteristics, procedural details, and inpatient outcome data were collected in the All New Zealand Acute Coronary Syndrome - Quality Improvement (ANZACS-QI) registry on consecutive patients undergoing ICA over five months. Of the 5894 ICAs 81% were via RA. Hospitals averaged 25 - 176 procedures/month (46.5% - 96.4% via RA). Operators averaged 17 procedures/month. Those performing more than 20 ICAs/month had RA rates between 61% - 99%. Of the 75 operators, 69% met the ESC recommendation. After multivariable adjustment higher operator (RR 1.12, CI 1.09 - 1.30) and hospital (RR 1.21, CI 1.15 - 1.28) volume were independent predictors of RA. Those with prior CABG (RR 0.51, CI 0.45 - 0.57), STEMI <12h (RR 0.91, CI 0.87 - 0.96), and female sex (RR 0.96, CI 0.94 - 0.99) were less likely to receive RA. CONCLUSIONS: New Zealand has a high RA rate for ICAs. Rates vary substantially between both operators and centres. Radial arterial was highest amongst the highest volume operators and centres.

Preparation of gallium nitride surfaces for atomic layer deposition of aluminum oxide.

A combined wet and dry cleaning process for GaN(0001) has been investigated with XPS and DFT-MD modeling to determine the molecular-level mechanisms for cleaning and the subsequent nucleation of gate oxide atomic layer deposition (ALD). In situ XPS studies show that for the wet sulfur treatment on GaN(0001), sulfur desorbs at room temperature in vacuum prior to gate oxide deposition. Angle resolved depth profiling XPS post-ALD deposition shows that the a-Al2O3 gate oxide bonds directly to the GaN substrate leaving both the gallium surface atoms and the oxide interfacial atoms with XPS chemical shifts consistent with bulk-like charge. These results are in agreement with DFT calculations that predict the oxide/GaN(0001) interface will have bulk-like charges and a low density of band gap states. This passivation is consistent with the oxide restoring the surface gallium atoms to tetrahedral bonding by eliminating the gallium empty dangling bonds on bulk terminated GaN(0001).

Psychology of earthquake-induced stress cardiomyopathy, myocardial infarction and non-cardiac chest pain.

AIMS: To compare psychological factors in patients presenting to hospital with earthquake-induced stress cardiomyopathy, myocardial infarction (MI) and non-cardiac chest pain. We hypothesised that patients with stress cardiomyopathy and non-cardiac chest pain would be more psychologically vulnerable than those with MI. METHODS: Cardiology admitting staff in the week following the September 2010 Christchurch earthquake prospectively identified patients with earthquake-precipitated chest pain. Males were excluded. All consenting women met diagnostic criteria for one of the three conditions. Patients underwent a semistructured interview with a senior clinical psychologist who was blind to the cardiac diagnosis. Premorbid psychological factors, experience of the earthquake and psychological response were assessed using a range of validated tools. RESULTS: Seventeen women were included in the study, six with stress cardiomyopathy, five with MI and six with non-cardiac chest pain. Earthquake experiences were notably similar across the groups. Patients with non-cardiac chest pain scored high on the hospital anxiety and depression scale, the health anxiety questionnaire, the Eysenck neuroticism scale and the Impact of Event scale. Women with stress cardiomyopathy scored as the most psychologically robust. Depression and extroversion scores were the same across groups. CONCLUSION: Our hypothesis was incorrect. Women with non-cardiac chest pain following an earthquake have higher anxiety and neuroticism scores than women with either MI or stress cardiomyopathy. Stress cardiomyopathy following an earthquake is not specific to psychologically vulnerable women. The psychology of natural disaster-induced stress cardiomyopathy may differ from that of sporadic cases.

Should the first priority in cardiovascular risk management be those with prior cardiovascular disease?

BACKGROUND: Cardiovascular disease (CVD) prevention guidelines typically dichotomise patients by history of CVD, as patients with prior CVD are assumed to be at high CVD risk, whatever their CVD risk profiles. OBJECTIVE: To assess the appropriateness of this practice by comparing CVD event rates of patients with and without prior CVD, over and above risk predicted by standard CVD risk factors. METHODS: Between 2002 and 2007 CVD risk assessments were generated using a web-based Framingham risk prediction algorithm in routine primary care. Individual risk profiles were subsequently linked to national hospitalisation and death records. Observed and predicted (Framingham) CVD risk were compared in patients with and without prior CVD. RESULTS: 35 760 patients were assessed including 10.4% with prior CVD. Of 1216 first CVD events during an average follow-up of 2.05 years, 42% occurred in those with prior CVD. Among those without prior CVD, the predicted Framingham five-year CVD risk was similar to the observed risk extrapolated to five years; in the highest Framingham risk band (>20% five-year risk), observed risk was 25.3%. Among those with prior CVD the observed risk extrapolated to five years rose from 21.7% in the lowest Framingham risk band (<5%) to 49% in the highest (>20%). CONCLUSIONS: Patients with prior CVD have five-year CVD risks approximately 20% higher, in absolute terms than patients without prior CVD, after accounting for standard risk factors. Almost half the CVD events occurred in those with prior CVD. These patients should be the highest priority for intensive preventive management in primary care.

B-type natriuretic peptide and left ventricular dysfunction on exercise echocardiography in patients with chronic aortic regurgitation.

OBJECTIVE: To determine whether plasma levels of B-type natriuretic peptide (BNP) predict left ventricular (LV) dysfunction on exercise echocardiography in patients with moderate to severe aortic regurgitation (AR). DESIGN: Case-control study. SETTING: Outpatient cardiology departments. PATIENTS: 39 asymptomatic or mildly symptomatic patients with chronic moderate to severe AR and a normal LV ejection fraction (>50%), and 10 normal controls. MAIN OUTCOME MEASURES: Plasma level of BNP and echocardiographic measures of LV function at rest and immediately after treadmill exercise. RESULTS: LV end systolic volume index (LVESVI) was significantly increased in AR patients with normal BNP (0.05 for all). However, there were modest but statistically significant associations between the plasma level of BNP and severity of AR indicated by a greater AR:LV outflow tract width ratio (r = 0.37, p = 0.02) and lower diastolic blood pressure (r = -0.44, p = 0.004). Increased BNP was also associated with a greater LVESVI (r = 0.33, p = 0.04) and lower LV longitudinal strain rate (r = -0.037, 0.02) on echocardiography after exercise. CONCLUSIONS: In moderate to severe AR compensatory LV remodelling can occur with no increase in plasma BNP. Increased BNP is associated with more severe regurgitation and changes consistent with early LV dysfunction on exercise echocardiography.

Transcatheter closure of a complex postmyocardial infarction ventricular septal defect after surgical patch dehiscence.

Ventricular septal defect (VSD) complicating acute myocardial infarction is a rare but serious event carrying a high mortality. Residual shunting after emergency surgical repair is common, adversely affects prognosis and can necessitate reoperation. We describe the successful transcatheter VSD closure with the Amplatzer occluder in a 75-year old man after earlier emergency surgical repair of a VSD complicating an acute myocardial infarction. The technique and positioning of the device in a tortuous infero-apical VSD are described.

Transmitral Doppler: a new transthoracic contrast method for patent foramen ovale detection and quantification.

OBJECTIVES: This study compared a new transthoracic echocardiographic (TTE) method for detection of right to left bubble passage, transmitral Doppler (TMD), against two-dimensional (2D) TTE contrast study and the gold standard, of transesophageal echocardiography (TEE), and assessed its utility in quantitative assessment of patent foramen ovales (PFO). BACKGROUND: Current TTE methods are relatively insensitive in PFO detection and do not allow quantitative assessment of right to left shunt. METHODS: In 44 patients (59 years, range 34 to 76 years) saline contrast and color Doppler studies were performed in three conditions--TTE TMD, TTE 2D and TEE. Bubble transit on the TMD was measured semiquantitatively by a visual bubble score and objectively by integrating the acoustic power within the mitral velocity envelope. RESULTS: By TEE it was determined that 17 patients (39%) had PFOs; 16 had right to left contrast passage, and only 1 had left to right flow by color Doppler. Against TEE contrast study, the sensitivity of TMD and 2D contrast studies were 100% and 75%, respectively, with specificity of 96% and 100%. Greater than 10 bubbles on a single beat of the resting contrast TMD identified patients with a maximum resting TEE PFO opening diameter >2 mm with 78% sensitivity and 100% specificity. There was a strong correlation (r2 = 0.72, p<0.01) between the TMD acoustic power and PFO opening diameter. CONCLUSIONS: Transmitral Doppler is a sensitive and specific method for TTE PFO detection that allows quantification of right to left bubble passage and may obviate the need for TEE in many patients after stroke.

Long stenting in native coronary arteries: relation between vessel size and outcome.

Procedural and 6-mo clinical outcomes were evaluated in 34 consecutive patients who had stenting (<40 mm) of a long segment of coronary artery. Procedural success was achieved in 32 (96%) patients. Before stenting, 32 (96%) patients had Canadian Cardiovascular Society Class 3 or 4 angina compared to 7 (21%) at 6-mo follow-up (P<0.001). Eleven patients (32%) suffered either acute/subacute stent thrombosis (n=4) or restenosis (n=7). On logistic regression distal reference diameter <2.5 mm (odds ratio 26, P<0.01) and previous cardiac intervention (odds ratio 9.0, P<0.01) were independent predictors of a major adverse event during follow-up. There was no significant association between outcome and indication for stenting, type of stent, or use of ticlopidine and aspirin. These results indicate that distal vessel diameter <2.5 mm is a powerful predictor of subacute thrombosis or restenosis after long coronary artery stenting.

Influence of heart rate on stroke volume variability in atrial fibrillation in patients with normal and impaired left ventricular function.

Both resting tachycardia and irregular ventricular rhythm may contribute to impaired cardiac performance in atrial fibrillation (AF). This study assesses the relation between resting heart rate and beat-to-beat changes in left ventricular (LV) ejection and filling in patients with normal and impaired LV systolic function. Beat-to-beat variation in LV outflow and inflow velocity-time integral was measured using pulsed Doppler ultrasound in 39 patients with chronic AF and normal (n=22) or impaired (n=17) LV systolic function. Aortic velocity-time integral variability increased with mean heart rate (p=0.003) even though RR interval variability decreased (p <0.001). Aortic velocity-time integral was more sensitive to the duration of both the preceding (p <0.001) and prepreceding (p <0.001) RR intervals at higher heart rates. These relations were similar for patients with normal and impaired LV systolic function. The sensitivity of the filling velocity-time integral to RR interval variability also increased with heart rate (p <0.001). However, at higher heart rates the filling velocity-time integral (p=0.009) and filling time (p=0.005) were less sensitive to change in RR intervals in patients with impaired LV function. We conclude that beat-to-beat stroke volume variability in AF increases with heart rate. Stroke volume variability was not influenced by LV systolic function.

Season of birth and schizophrenia: southern hemisphere data.

OBJECTIVE: The association between winter birth and increased incidence of schizophrenia is well documented in the northern hemisphere. The present study examined season of birth and schizophrenia in a southern hemisphere population from a mild temperate climate. METHOD: The seasonal incidence of birth in schizophrenic patients was compared, using Chi-squared tests, to normative population birth rates. RESULTS: A statistically significant seasonal pattern, with a peak in late spring and early summer, was obtained. CONCLUSION: This supports northern hemisphere findings regarding calendar month, but not season, of excess schizophrenic births. This has implications for viral and other aetiological hypotheses dependent on meteorological factors.

Amantadine and sparteine inhibit ATP-regulated K-currents in the insulin-secreting beta-cell line, HIT-T15.

1. The effects of pharmacological agents that potentiate insulin release were studied on ATP-regulated K-currents (K-ATP currents) in the insulin-secreting beta-cell line HIT-T15 by use of patch-clamp methods. 2. The tricyclic drug, 1-adamantanamine (amantadine), reversibly inhibited both whole-cell currents (with a Ki of 120 microM) and single channel currents in inside-out patches. This effect was principally due to an increase in a long closed state which reduced the channel open probability. The related compound, 1-adamantanol, in which the amino group is substituted by a hydroxyl one, did not inhibit K-ATP currents substantially. 3. The alkaloid, sparteine, reversibly inhibited both whole-cell K-ATP currents (Ki = 171 microM) and single channel currents in inside-out patches. 4. The results suggest that sparteine and amantadine can block the K-ATP channel from either side of the membrane and support the idea that at least part of the stimulatory effect of these agents on insulin secretion results from inhibition of this channel.