The long-term mortality of an Aboriginal and Torres Strait Islander Australian population after isolated coronary artery bypass graft surgery.

BACKGROUND: Aboriginal and Torres Strait Islander (Indigenous) Australians have an increased prevalence of coronary artery disease and present at a younger age for coronary artery bypass graft surgery (CABG) when compared to non-Indigenous Australians. Studies have reported postoperative outcomes in Indigenous people to be less favourable. Therefore, the aim of this study is to evaluate long term mortality between Indigenous and non-Indigenous people post-CABG. METHODS: We analysed data on all patients who underwent isolated CABG, with and without cardiopulmonary bypass, at our institution between January 1998 to September 2008. There were 33 395 person-years of survival for analysis with a median follow-up of 13 years (Interquartile range (IQR): 8-16 years). We analysed all-cause mortality with the Kaplan-Meier graph and log-rank test. Univariate and multivariate analysis was performed using a Cox proportional hazards model. RESULTS: The mean age at presentation for Indigenous people was 52 years compared to 65 yr for non-indigenous people. There were 1431 (52.1%) deaths by the study census date, with the overall mortality for Indigenous patients at 49.8% (n = 147) and 52.4% for non-Aboriginal patients (n = 1284). The age and comorbidities adjusted hazard ratio (HR) for all-cause late mortality (median years) was HR = 1.712 (95% CI: 1.288-2.277, p < 0.001). CONCLUSION: Indigenous patients present for CABG at a younger age and have a higher prevalence of comorbidities. Our study demonstrates they have a higher risk of propensity adjusted all-cause long term mortality. Primary and secondary prevention strategies, tailored to Indigenous people, may improve health outcomes in the long-term post-CABG.

Quality of life following cardiac rehabilitation in cardiac surgery patients.

BACKGROUND: Undergoing cardiac surgery often result in perioperative loss of health-related quality of life (HRQOL). Although participation rates in Australia is low, cardiac rehabilitation (CR) has been demonstrated to improve patient HRQOL in cardiac patients. Literature is unclear regarding the role of CR and HRQOL in the cardiac surgery (CS) patient population. METHODS: A prospective non-randomised study was conducted on eligible cardiac surgery patients between December 2009 and March 2015. HRQOL was assessed using the Short Form 12 at baseline and post-operatively at 30 days and 180 days. CR participation was recorded and barriers to CR uptake was assessed using the Cardiac Rehabilitation Enrolment Obstacles (CREO) scale. RESULTS: At 180 days, 107 patients participated in CR and 111 did not participate in CR. A significant improvement from baseline mental and physical HRQOL was observed in both groups at 30 days and 180 days (p < 0.002). No significant difference between group characteristics or HRQOL was observed at any time. A trend of superior improvement in mental QOL was observed in the CR group. The study is limited by poor initial uptake (218/1772 of eligible) and may be underpowered to observe a clinical difference. A significant difference in CREO scores were observed between the two groups at 30 days (13 out of 16 questions, p < 0.001) and 180 days (11 out of 16 questions, p < 0.011). CONCLUSION: Literature has shown that CR may improve numerous health outcomes in cardiac and CS patients, however CR uptake in Australia is low. Mental and Physical QOL is demonstrated to improve following CS, however further research is required to delineate the role of CR and QOL in CS patients. The CREO tool utilised in this study identified numerous potentially modifiable barriers to CR uptake. Specific strategies related to the survey are suggested to improve awareness, uptake, and adherence to CR, including advocacy of home-based and telehealth services.

Prognostic Value of High-Sensitivity Troponin T After On-Pump Coronary Artery Bypass Graft Surgery.

INTRODUCTION: High-sensitivity troponin T (hs-TnT), as a single or serial measurement to predict postoperative mortality and morbidity, appears to be attractive due to its direct relationship in assessing myocardial damage and the widespread availability of hs-TnT testing. Therefore, this study aimed to identify any prognostic value of hs-TnT in predicting in-hospital outcomes after coronary artery bypass graft (CABG) surgery. METHOD: We identified all consecutive patients who underwent on-pump CABG between July 2011 and December 2018. To evaluate the prognostic value of hs-TnT after CABG, we assessed the probability and odds ratio (OR) of adverse events concerning the maximum value of postoperative hs-TnT (measured within 24 hrs). TnT was routinely collected at 0, 6, 12 and 72 hours postoperatively. Values were categorised into intervals of 200 for analysis. A fully Bayesian logistic regression of the adverse event with the troponin T interval (0-200) as the reference level was used. A subgroup analysis was performed in patients with normal and elevated preoperative hs-TnT (< or ≥30 ng/L). The pre-specified primary outcome was a major adverse cardiac or cerebrovascular event (MACCE), defined as a composite of death within 30 days of operation for any cause, myocardial infection (MI), or stroke. RESULTS: 1,318 people underwent on-pump CABG during this period. One hundred and twenty-three (123) (9.3%) experienced MACCE, 14 (1.1%) experienced death within 30 days, 105 (8.0%) experienced MI and 14 (1.1%) experienced stroke. Compared to the reference category (hs-TnT ≤200 ng/L) we found there was an increase in OR with increasing level of hs-TnT for MACCE (p<0.001), 30-day mortality (p=0.003), MI (p<0.001) and ICU stay >48 hours (p<0.001). However, there was no statistically significant association present between hs-TnT and stroke, readmission to the intensive care unit (ICU), return to theatre for bleeding, or new-onset renal dysfunction. CONCLUSION: Peak hs-TnT level, greater than 400 ng/L, measured within 24 hours after CABG surgery is associated with MACCE, 30-day mortality, MI and ICU stay >48 hours. Prospectively designed trials, with clear prognostic and outcome variables, may provide further insight into the prognostic value of hs-TnT post-CABG.

Public Health Costs for Northern Territory and South Australian Cardiac Surgery Patients.

BACKGROUND: The cost of performing cardiac surgery in the public health system in Australia is unclear. This paper analyses the cost of cardiac surgery performed at Flinders Medical Centre (FMC), South Australia, comparing cost by procedure, rheumatic valvular heart disease status, Aboriginality and location. METHODS: This study is a retrospective, population-based analysis of cardiac surgery data held in the Cardiac Surgery Registry cross-referenced to cost data provided by the FMC Department of Finance and Patient Travel, Accommodation and Transport Services at the Royal Darwin Hospital. Seven hundred ninety-five (795) patients who underwent cardiac surgery at FMC from 1 July 2014 to 30 June 2016 were included. RESULTS: Across all procedures, Northern Territory (NT) Aboriginal patients had a mean total cost of $78,506 which was $24,113 more than NT non-Aboriginal, $28,443 more than South Australian (SA) Aboriginal and $22,955 more than SA non-Aboriginal patients. The total cost of a patient undergoing a repeat sternotomy (reoperative procedure) was found to be significantly higher than a primary procedure ($85,797 versus $59,097). In patients undergoing valve surgery procedures, those identified with rheumatic heart disease had a higher mean total cost than those without (a difference of $25,094). Significantly, the rheumatic patient group showed a higher proportion of reoperative procedures (19% versus 5%). CONCLUSIONS: The cost of treating NT Aboriginal cardiac surgical patients remotely has a significant financial impact upon the health care delivery system, as does the impact of rheumatic heart disease. This study found that the cost for the NT Aboriginal patient group was substantially higher than the NT non-Aboriginal, SA Aboriginal and SA non-Aboriginal patient groups. The additional cost to family and dislocation of social structures is not able to be calculated, but would also clearly weigh heavily on both patient groups. These findings suggest that future health funding models should recognise Aboriginality, remoteness and rheumatic heart disease.