Evaluation of the effects of three designs of oxygenators with integrated filters on clinical and haematological outcomes at an Australasian cardiothoracic unit.

INTRODUCTION: Cardiopulmonary bypass (CPB) machines have oxygenators with integrated filters and unique biocompatible coatings to combat systemic inflammatory response syndrome (SIRS) and mitigate coagulopathy. Contemporary oxygenators have undergone comparative studies; however, our study aimed to identify the most appropriate oxygenator for our regional Cardiothoracic unit in Australasia. METHODS: A prospective audit consecutively recruited one-hundred and fifty patients undergoing cardiac surgery at Waikato Hospital, New Zealand between the periods of 29th January 2018 and 31st July 2018. Fifty patients were recruited for each oxygenator arm: Sorin INSPIRE' (Group-S); Terumo CAPIOX'FX (Group-T); and Medtronic Affinity Fusion' (Group-M). The clinical outcomes were transfusions, chest drain output, reoperation and length of hospital stay (LOHS). Routine blood testing protocol included: haemoglobin, protein, albumin, white cell count (WCC), C-reactive protein (CRP), platelet count and coagulations tests including international normalized ratio (INR). RESULTS: Comparing Groups S, T and M there was no statistical difference in chest drain output (650 vs. 500 vs. 595 ml respectively, p = 0.45), transfusions (61 vs. 117 vs. 70 units, p = 0.67), reoperation (6 vs. 8 vs. 12%, p = 0.99) and LOHS (median 7.4 vs. 7.6 vs. 9.5 days, p = 0.42). Group-T had fewer SIRS cases but similar increase in CRP (p = 0.12) and WCC (p = 0.35). Group-M had a significant rise in post-op INR (p = 0.005) but no associated increase in chest drain output (p = 0.62). Group-S and -M required more 4%-albumin and Group-T had more transfusions. Only fresh frozen plasma (FFP) and red blood cell (RBC) transfusion had a significant relationship with LOHS (p < 0.05). CONCLUSION: Biochemically, there was slight difference among the oxygenators which did not translate into clinical difference in outcomes. The oxygenator design and perfusionist choice aided in our decision-making process.

Early diagnosis of surgically curable lung cancer is commonly serendipitous.

AIMS: Lung cancer is the largest cause of cancer death in New Zealand, accounting for 18.3% of cancer-related deaths.[[1,2]] There is limited literature on how patients with lung cancer clinically present in New Zealand. The aim of this cohort study was to identify the rate of incidentally diagnosed lung cancer in the Midland Region, the common symptomatology and route of diagnosis. METHODS: This retrospective cohort study included patients with lung cancer who underwent potentially curative thoracic surgery between January 2011 to June 2018 at Waikato Hospital, New Zealand. Symptoms or signs recorded were cough, dyspnoea, haemoptysis, lymphadenopathy, chest pain, hoarseness, fatigue, weight loss and finger clubbing. The lung cancer cases were grouped into incidental finding, symptomatic general practitioner, symptomatic emergency department and surveillance. RESULTS: Three hundred and ten patients with lung cancer had thoracic surgery with curative intent at Waikato Hospital. Two hundred and fourteen (69%) patients had symptoms which prompted presentation to a treating physician and 96 (31%) patients were asymptomatic. Incidental diagnosis was demonstrated in 121 (39.4%) patients. Of the patients diagnosed incidentally, 36.4% (n=44) had symptoms of lung cancer with the main symptoms including 45% with cough (n=20), 28% with dyspnoea (n=12) and 28% chest pain (n=12). CONCLUSIONS: In New Zealand, a large amount of lung cancer is still diagnosed incidentally with symptoms of cough, dyspnoea and chest pain. Further research into the development of a lung cancer screening program in New Zealand for a high-risk population is warranted.

Performance of the AusSCORE II and STS Score for Coronary Artery Bypass Grafting in a New Zealand Population.

BACKGROUND: The updated Australian System for Cardiac Operative Risk Evaluation (AusSCORE II) and the Society of Thoracic Surgeons (STS) Score are well-established tools in cardiac surgery for estimating operative mortality risk. No validation analysis of both risk models has been undertaken for a contemporary New Zealand population undergoing isolated coronary bypass surgery. We therefore aimed to assess the efficacy of these models in predicting mortality for New Zealand patients receiving isolated coronary artery bypass grafting (CABG). MATERIAL AND METHODS: A prospective database was maintained of patients undergoing isolated CABG at a major tertiary referral centre in New Zealand between September 2014 and September 2017. This database collected the patients' demographic, clinical, biochemical, operative and mortality data. The primary outcome measure was the correlation between the predicted AusSCORE II and STS Score mortality risks and the observed 30-day mortality events for all patients in the database using discrimination and calibration statistics. Discrimination and calibration were assessed using receiver operating characteristic (ROC) curves and the Hosmer-Lemeshow test respectively. RESULTS: A total of 933 patients underwent isolated CABG during the 3-year study period. There were seven deaths in the study cohort occurring within 30 days of surgery. Discrimination analysis demonstrated the area under the ROC curve (AUC) of the AusSCORE II and STS Score as 88.2% (95% CI: 85.9-90.2, p<0.0001) and 92.1% (95% CI: 90.2-93.7, p<0.0001) respectively. Calibration analysis revealed Hosmer-Lemeshow test p-values for the AusSCORE II and STS Score as 0.696 and 0.294 respectively. DISCUSSION: ROC curve analysis produced very high and statistically significant AUC values for the AusSCORE II and STS Score. Hosmer-Lemeshow test analysis revealed that both risk scoring tools are well calibrated for our study cohort. Therefore, the AusSCORE II and STS Score are both strongly predictive of 30-day mortality for isolated coronary artery bypass grafting surgery in our New Zealand patient population. Both risk models have performed with excellent discrimination and calibration. There is, however, a need to consider the performance of these risk stratification models in other cardiac surgical procedures outside isolated coronary bypass surgery where appropriate.

Management of patients with early stage lung cancer - why do some patients not receive treatment with curative intent?

BACKGROUNDS: This study aims to understand the factors that influence whether patients receive potentially curative treatment for early stage lung cancer. A key question was whether indigenous Maori patients were less likely to receive treatment. METHODS: Patients included those diagnosed with early stage lung cancer in 2011-2018 and resident in the New Zealand Midland Cancer Network region. Logistic regression model was used to estimate the odds ratios of having curative surgery/ treatment. The Kaplan Meier method was used to examine the all-cause survival and Cox proportional hazard model was used to estimate the hazard ratio of death. RESULTS: In total 419/583 (71.9%) of patients with Stage I and II disease were treated with curative intent - 272 (46.7%) patients had curative surgery. Patients not receiving potentially curative treatment were older, were less likely to have non-small cell lung cancer (NSCLC), had poorer lung function and were more likely to have an ECOG performance status of 2+. Current smokers were less likely to be treated with surgery and more likely to receive treatment with radiotherapy and chemotherapy. Those who were treated with surgery had a 2-year survival of 87.8% (95% CI: 83.8-91.8%) and 5-year survival of 69.6% (95% CI: 63.2-76.0%). Stereotactic ablative body radiotherapy (SABR) has equivalent effect on survival compared to curative surgery (hazard ratio: 0.77, 95% CI: 0.37-1.61). After adjustment we could find no difference in treatment and survival between Maori and non-Maori. CONCLUSIONS: The majority of patients with stage I and II lung cancer are managed with potentially curative treatment - mainly surgery and increasingly with SABR. The outcomes of those being diagnosed with stage I and II disease and receiving treatment is positive with 70% surviving 5 years.

Assessment of the EuroSCORE II in a New Zealand Tertiary Centre.

BACKGROUND: The updated European System for Cardiac Operative Risk Evaluation (EuroSCORE II) is a well-established cardiac surgery risk scoring tool for estimating operative mortality. This risk stratification system was derived from a predominantly European patient cohort. No validation analysis of this risk model has been undertaken for the New Zealand population across all major cardiac surgery procedures. We aim to assess the efficacy (discrimination and calibration) of the EuroSCORE II for predicting mortality in cardiac surgical patients at a large New Zealand tertiary centre. METHODS: Data was prospectively collected on patients undergoing cardiac surgery from September 2014 to September 2017 at Waikato Hospital, New Zealand. Patient demographic information, preoperative clinical risk factors and outcome data were entered into a national database. Included patients received either isolated coronary artery bypass grafting (CABG), isolated valve surgery, isolated thoracic aortic surgery, or a combination of these procedures. The primary outcome was the discrimination and calibration of predicted EuroSCORE II risk scores compared with observed 30-day mortality events. RESULTS: 1,666 cardiac surgery patients were included during the study period, with an average EuroSCORE II of 2.97% (95% confidence interval (CI): 2.76-3.18). Nine hundred thirty-three (933) patients underwent isolated CABG, 384 underwent isolated valve surgery, 48 received isolated thoracic aortic surgery and 301 received combination procedures. Thirty-day (30-day) mortality events in each of these groups was 7, 4, 2 and 13 deaths respectively. There were 26 deaths across the total cohort at 30-days (observed mortality rate 1.56%). Discrimination analysis using receiver operating characteristic curves demonstrated the area under the curve (AUC) of the EuroSCORE II in each of these groups as 93.4% (95% CI: 91.6-94.9, p<0.0001), 66.3% (95% CI: 61.3-71.0, p=0.37), 37.0% (95% CI: 15.7-58.2, p=0.23) and 74.8% (95% CI: 69.5-79.6, p<0.0001) respectively. The total cohort AUC was 83.1% (95% CI: 81.2-84.9, p<0.0001). Calibration analysis using Hosmer-Lemeshow tests for the subgroups revealed p-values of 0.848, 0.114, 0.638 and 0.2 respectively. The total cohort Hosmer-Lemeshow p-value was 0.317. CONCLUSIONS: EuroSCORE II showed a strong discriminative ability for isolated CABG 30-day mortality in a New Zealand patient cohort. However, the scoring system discriminated poorly across valvular, thoracic aortic or complex combination cardiac surgical procedures. Good calibration of the EuroSCORE II was achieved across both the total cohort and subgroups. It is important to consider the performance of other cardiac surgery risk stratification models for the New Zealand population.

Early Discharge From Intensive Care After Cardiac Surgery is Feasible With an Adequate Fast Track, Stepdown Unit: Waikato Experience.

BACKGROUND: Enhanced recovery programs within cardiothoracic surgery are a well described benefit to patient postoperative outcomes. We describe our Australasian unit's experience of a day zero discharge enhanced recovery unit from the intensive care department. METHODS: A retrospective study was conducted on a prospectively maintained database at Waikato Cardiothoracic Unit from September 2014 till October 2017 with 1,739 patients undergoing cardiac surgery. Twenty-two (22) patients were excluded as deaths either intraoperative or in the intensive care unit (ICU) and therefore never discharged. Total population of the study was 1,717 patients. The primary endpoint of this study was to determine if there is no survival disadvantage for the day zero discharge unit compared to standard treatment in ICU at follow-up. The secondary endpoint of the study was to highlight the association between pre and postoperative variables and the impact on discharge from the ICU. RESULTS: One hundred sixty-eight (168) patients were discharged to the enhanced recovery unit (ERU) day zero. Mean number of hours spent in ICU for the day zero cohort was 7.18 (±1.59. Mean Age 62.5 (±11.22), M:F 4.25:1. Patients were more likely to be discharged day zero if they had a lower EuroSCORE II 1.57 (±1.67) and lower preoperative creatinine 89.4 (±27.5). Those admitted to the ERU on day zero postoperatively were more likely to be discharged with a lower creatinine level, a higher haemoglobin level and have less readmissions per 30days (p<0.05). Survival analysis demonstrated that the patients who were discharged early from ICU had significantly better follow-up survival compared to those who were discharged after 24hours (p<0.05). CONCLUSIONS: A fast track unit increases the efficiency of an ICU and cardiac surgical department. With the advancements of cardiac surgery a higher number of patients will be suitable for a fast track method. Our unit has demonstrated that a day zero fast track unit in New Zealand can perform with adequate patient safety with no increased risk of mortality and with low rates of failure of the day zero discharge fast track therapy.

Predicting adverse outcomes in elective coronary artery bypass graft surgery using pre-operative troponin I levels.

BACKGROUND: Cardiac troponins are frequently measured as part of the pre-operative work-up of patients prior to coronary artery bypass graft surgery (CABG). The utility of measuring these levels in elective patients, and the clinical implication of an abnormal result are unclear. The following study investigates the relationship between cardiac troponin I (cTnI) measured as part of a routine pre-operative work-up and outcomes following CABG. METHODS: From January 2010 to December 2012, 378 patients underwent isolated, elective CABG and had cTnI measured prospectively, as part of their pre-operative work-up. Patients were divided into normal (Group I) and elevated (Group II) cTnI groups. Pre-operative, operative and post-operative data were obtained from our institution's prospectively collected database. RESULTS: Elevated cTnI was present in 47 patients (12.4%) pre-operatively. Intra-operative variables did not differ between the elevated cTnI and control groups. Both 30-day mortality (Group I: 0.9% v Group II: 6.4%, p=0.03) and cardiac arrest (Group I: 1.5% v Group II: 8.5%, p=0.01) were significantly more frequent in the elevated cTnI group. In multivariable analysis, elevated cTnI remained a predictor for cardiac arrest (OR 5.8, 95% CI 1.2 - 29.2). CONCLUSIONS: Patients presenting for elective CABG frequently have elevated cTnI on pre-operative work-up. These patients may be at a greater risk of 30-day mortality and cardiac arrest. Routine pre-operative measurement of cTnI may alert clinicians to a higher operative risk.

Clinicopathological and surgical experience with primary cardiac tumors.

BACKGROUND: Intracardiac tumors are rare neoplasms that present with clinical features of obstruction, embolization, conduction disturbances, and constitutional symptoms. Complete surgical resection under cardiopulmonary bypass offers the best prospect of disease-free survival. METHODS: Data of 30 consecutive patients who underwent resection of an intracardiac mass at St. Vincent's Hospital from 1990 to 2012 were reviewed. RESULTS: The patients presented with dyspnea (33%), palpitations or arrhythmias (20%), and recurrent pulmonary edema (6%). There was a history of embolic stroke in 46%. Intracardiac masses were identified using preoperative echocardiography. Resection was performed on cardiopulmonary bypass via a modified Dubost (superior transseptal) approach in 78%, a left atriotomy in 11%, and a biatrial approach in 5%. Twenty-eight (93%) masses were identified as neoplastic, predominantly myxomas (62%). There was no mortality at 30 days. On long-term follow-up (mean 9 years, range 1-19 years) there were 5 deaths; 83% of patients were still alive. CONCLUSIONS: Cardiac tumors are rare and an important differential diagnosis in the context of unexplained obstructive symptoms, emboli, and conduction abnormalities. Myxomas are the most common cardiac neoplasm. Solid tumors are more common, more likely to be associated with heart failure, and best excised in one whole part, whereas papillary tumors are more likely to be associated with neurological symptoms, and more likely to be resected by piecemeal removal. Prompt and complete resection under cardiopulmonary bypass is the safest approach.

Prophylactic epicardial left ventricular lead implantation for biventricular pacing during operations.

BACKGROUND: Surgical epicardial left ventricular (LV) lead implantation for biventricular pacing has advantages over the transvenous approach in cardiac surgical patients. We investigated the benefit of concomitant prophylactic LV lead implantation during open heart operations and subsequent lead performance after patients with impaired LV function receive a biventricular device. METHODS: Retrospective data of 4,844 patients undergoing cardiac operations through a sternotomy between January 2001 and December 2011 were analyzed. Of these, 380 patients (7.8%) had severe impairment of LV function (contrast left ventriculogram showing grade 4 estimated ejection fraction or echocardiogram showing LV ejection fraction<0.30). LV lead implantation was performed in patients in whom recovery of LV function was unlikely. Lead performance data were collected at follow-up. RESULTS: LV lead implantation occurred in 95 patients (25%), and 29 (30.5%) subsequently received a biventricular device. Of patients with impaired LV function, more patients with prophylactic LV leads underwent biventricular implant than those without LV leads (30.5% vs 1.1%, p<0.0001). The median interval from LV lead implantation to connection to a biventricular device was 30 days (interquartile range, 5.5 to 145 days). At a median follow-up of 437.5 days (interquartile range, 13.8 to 1198 days), the mean pacing threshold (1.25±0.46 vs 1.58±0.66 volts, p=0.069) and impedance (383.81±70.33 vs 448.6±200.1 Ohms, p=0.168) remained stable compared with time of biventricular device connection. CONCLUSIONS: A significant proportion of patients with poor LV function undergoing cardiac operations may benefit from concomitant LV lead implantation. Subsequent lead performance appears satisfactory. Epicardial LV lead placement is easily accomplished during open heart operations and should be considered before the operation.

Augmenting pancreatic anastomosis during whipple operation with fibrin glue: a beneficial technical modification?

INTRODUCTION: Various techniques have been described to try and reduce the rate of anastomotic leak following pancreaticoduodenectomy, which remains a challenge for pancreatic surgeons worldwide. We outline a technique to reinforce the pancreatic anastomosis with a double layer of fibrin glue between suture lines. METHODS: Our technique for pancreatic anastomosis is described in detail. A review of consecutive pancreaticoduodenectomies by a single surgeon (NAC) since introduction of fibrin glue anastomosis reinforcement was compared with a historical control cohort performed by the same surgeon. RESULTS: Thirty-two consecutive pancreaticoduodenectomies were undertaken between March 2008 and March 2012 by a single surgeon, 30 patients had fibrin glue augmentation of the pancreatico-gastrostomy anastomosis. Median length of stay was 12 days. There were no pancreatic leaks or mortality since adopting fibrin glue for the pancreatic anastomosis; however; this single surgeon series is not large enough to provide statistical evidence of a difference since glue was adopted. DISCUSSION: Our results since the incorporation of this step in pancreaticoduodenectomy are encouraging. Selective use of glue is worthy of consideration in difficult cases, although confirmation of a reduction in pancreatic leak rate is not yet established, and we advocate a multi-institution randomized controlled trial to explore this.

Acute repair of traumatic tricuspid valve regurgitation aided by three-dimensional echocardiography.

A 54 year-old man without prior cardiac history was involved in a motor vehicle accident. His heart rate was 100/min and blood pressure 128/78 mmHg. He complained of anterior chest pain, and on examination had a loud pan-systolic murmur with no clinical signs of heart failure. Three-dimensional trans-oesophageal echocardiography (3D-TOE) demonstrated partial rupture of the inferior head of the anterior papillary muscle (when 2D-TOE did not), causing severe tricuspid regurgitation. This was successfully repaired. Tricuspid valve insufficiency is a rare, but well documented, complication of blunt chest trauma. The majority of cases of tricuspid regurgitation caused by blunt trauma are diagnosed and treated late after the traumatic event. Acute diagnosis is less common but possible with a high level of vigilance, and is greatly aided by clinical indicators of cardiac injury. We describe a case of acute repair of traumatic tricuspid insufficiency, in which diagnosis and surgical planning were greatly aided by 3D-TOE.

Implications for cardiac surgery in patients with factor XII deficiency.

Factor XII deficiency is associated with a prolonged activated partial thromboplastin time and activated clotting time used for monitoring during cardiopulmonary bypass. It does not predispose to an increased risk of bleeding. We present the strategy used for a case of coronary artery bypass grafting in a patient with factor XII deficiency, followed by a brief discussion of the important clinical considerations when patients with factor XII deficiency undergo cardiac surgery. Monitoring of heparin and the avoidance of anti-fibrinolytic agents are the main intraoperative issues. Postoperative care must include careful thromboembolic prophylaxis and vigilance against infection.

Surgical stabilization of rib fractures using Inion OTPS wraps--techniques and quality of life follow-up.

BACKGROUND: A variety of operative techniques have been described in the past for the surgical stabilization of fractured ribs. METHODS: From February 2004 to November 2008, consecutive patients who underwent open reduction and internal fixation of traumatic fractured ribs during their index admission using the Inion orthopedic trauma plating system (OTPS) at a Level I trauma center were retrospectively analyzed. Demographics, Injury Severity Scores, number and site of rib fractures, operative details, and complications were recorded. All patients were followed-up with a questionnaire assessing chest symptoms, disability, and quality of life. RESULTS: Thirty-two patients underwent surgical stabilization with Inion OTPS. Road crashes were the commonest mechanism of injury (81%), followed by falls. Seventy-two percent of patients were male, with a median age at operation of 53 years (interquartile range [IQR], 40-64 years). Median number of ribs fixed was 3 (IQR, 2-4), while median number of fractures was 9 (IQR, 6-13). Median time to fixation was 5 days (IQR, 3-7 days), intensive care unit stay 3 days (IQR, 0.8-6.3 days), and total hospital stay 13.5 days (IQR, 8.8-22 days). Wound infection occurred in 19%, with nonunion of a fixed fracture in one patient. Sixty-three percent of patients completed the survey with a mean time between open reduction and internal fixation and questionnaire of 1,039 days (+/-480 days). Patients reported low levels of pain at rest and with coughing (median at rest 1.0/10 [IQR, 0-2.3/10]; with coughing 1.3/10 [IQR, 0-3.75/10]). Chest wall stiffness was experienced by 60% of patients, while dyspnoea at rest was reported by 20% of patients. Mean return to work (for 55%) was 3.9 months (+/-3.3 months). All patients were satisfied with the results of their operation. CONCLUSION: Patients demonstrated low levels of pain and satisfactory rehabilitation. The Inion OTPS system has several advantages including gradual transference of stress loads to bone, micromotion across the fracture site, and easy wrapping of comminuted fractures. This technique allows excellent stabilization of fractured ribs, with good clinical results in ambulant and ventilated patients, both with initial and with midterm follow-up.

Comparison of reduction ascending aortoplasty and ascending aortic replacement for bicuspid valve related aortopathy in young adult patients undergoing aortic valve replacement--long-term follow-up.

BACKGROUND: We aimed to determine the long-term outcomes of reduction ascending aortoplasty and ascending aortic replacement. A secondary aim was to document our experience with the long-term "growth" of woven Dacron grafts. METHODS: Over a nine-year period (1992-2001), 154 patients underwent aortic valve replacement using the Ross procedure for bicuspid aortic valve disease (BAV). Twenty-five also underwent reduction ascending aortoplasty (RAA), and 16 underwent ascending aorta replacement (AAR), using a Dacron graft. Preoperative diameters were measured prospectively. Patients had a follow-up CT chest between January and December 2007 to measure the mid-ascending aortic diameter. RESULTS: Mean age at operation was 31.8+/-13.5 years (RAA), and 40.0+/-8.6 years (AAR) (p=NS). Mean follow-up was 101 months (+/-43.0, 95% CI) in the RAA group, and 107 months (+/-29.0, 95% CI) in the AAR group. Mean pre-operative diameter in the RAA group was 41.5mm (+/-11.8, 95% CI) and in the AAR group 46.2mm (+/-7.8, 95% CI) (p=0.004). Mean follow-up diameter in the RAA group was 35.4mm (+/-4.6, 95% CI) and in the AAR group 31.9 mm (+/-6.8, 95% CI) (p=0.003). Growth of the woven Dacron prosthesis was 23.4% (+/-26.8, 95% CI) in the 107-month follow-up period. There was no early or late mortality and no further aortic surgery during follow-up. CONCLUSIONS: We have demonstrated satisfactory long-term outcomes with both RAA and AAR in patients with BAV related aortopathy who have undergone the Ross procedure. We have noted a greater diameter reduction with AAR when compared with RAA over nine years. In this series, "growth" of the woven Dacron grafts occurred, however individual measures did not correlate with other studies.

Management of unstable angina and non-ST-elevation myocardial infarction: do cardiologists do it better? A comparison of secondary and tertiary centre management in New Zealand.

BACKGROUND: Internationally, differences have been noted in how specialist cardiologists and general physicians manage acute coronary syndromes (ACS). Whether a similar practice difference exists in New Zealand is unclear. AIM: To test the hypothesis that management differences exist between cardiologists and general physicians in patients presenting with a non-ST-segment elevation acute coronary syndrome in a New Zealand setting-and whether these differences (if present) impact on patient outcome. METHODS: A retrospective chart review of 324 consecutive patients presenting with a non-ST-segment elevation acute coronary syndrome to Taranaki Base and Waikato Hospitals from 1 January 1999 was undertaken. Patients in Taranaki were managed by general physicians and in Waikato they were managed by cardiologists. RESULTS: Patients presenting to Taranaki Base Hospital were more likely to have high-risk ECG changes with ST-segment depression noted in 34.4% of patients there compared to 16.8% of patients in Waikato (p<0.001). Medical management during patient stabilisation was similar in Taranaki and Waikato with high use of anti-thrombotic (89%) and anti-platelet therapy (94%), respectively. However angiography (5.1% versus 23.4%; p=0.0045) and revascularisation procedures (4% versus 16.7%; p=0.0002) were performed less frequently in Taranaki. No significant difference was noted in mortality at 6 months (9.6% in Waikato versus 13.4% in Taranaki; p=0.4) Readmission rates were also similar; occurring overall in approximately one-quarter of the study population. CONCLUSION: In New Zealand, differences exist in how cardiologists and general physicians manage non-ST-elevation acute coronary syndrome. In particular, the low referral rates for angiography by general physicians is of concern and requires correction as current best-practice guidelines suggest high-risk patients are disadvantaged by a conservative approach to management.