M. Horsfall

Perceived Risk of Ischemic and Bleeding Events in Acute Coronary Syndromes

Background— Acute coronary syndrome registries report the use of incomplete guideline therapies, especially among the highest risk patients. Whether this treatment gap results from misperceptions of risk by physicians is uncertain. Methods and Results— The Perceived Risk of Ischemic and Bleeding Events in Acute Coronary Syndrome Patients (PREDICT) study was a prospective acute coronary syndrome registry in Australia, China, India, and Russia, involving 58 hospitals between May 2009 and February 2011. In-hospital care and events up to 6 months were assessed. At least 2 clinicians involved in patient care estimated the untreated risk and change in risk with each therapy. Physician risk assessment and objective risk measures (eg, Global Registry of Acute Coronary Events [GRACE] score) for death, death/myocardial infarction, and bleeding events were compared using the c statistic and integrated discrimination improvement. In total, 1542 patients and 4230 patient-specific physician estimates were obtained. Of responding clinicians, 81.9% were cardiovascular specialists (years of practice: mean [SD], 11.5 [7.7] years). The median physician-perceived risk of 6-month death was 25% (interquartile range, 14%–35%). The GRACE score was superior to physician estimation (c statistic: GRACE score, 0.812 [95% confidence interval, 0.772–0.851] versus physician, 0.652 [95% confidence interval, 0.596–0.708]; P<0.0001). The GRACE score added to clinician intuition improved discrimination (integrated discrimination improvement, 0.0632 [SE, 0.012]; P<0.0001). Invasive management correlated with physician-estimated risk but not with GRACE risk. Among patients not at high risk by physician estimation, increased risk by GRACE score was associated with higher mortality (3.7% versus 0.8%; P<0.001). Conclusions— Objective risk assessment provides superior risk discrimination when compared with physician-estimated risk. Whether systematic use of objective risk stratification improves clinical outcomes should be studied in appropriately designed clinical trials.

Randomized Comparison of High-Sensitivity Troponin Reporting in Undifferentiated Chest Pain Assessment

Background—High-sensitivity troponin T (hs-TnT) assays promise greater discrimination of evolving myocardial infarction, but the impact of unguided implementation on the effectiveness of care is uncertain. Methods and Results—We evaluated the impact of hs-TnT reporting on care and outcome among chest pain patients presenting to 5 emergency departments within a multicenter randomized trial. Patients were allocated to hs-TnT reporting (hs-report) or standard reporting (std-report; Roche Elecys). The primary end point was death and new or recurrent acute coronary syndrome by 12 months. A total of 1937 patients without ST-segment elevation were enrolled between July 2011 and March 2013. The median age was 61 (interquartile range, 48–74) years, and 46.3% were women. During the index hospitalization, 1466 patients (75.7%) had maximal troponin <30 ng/L within 24 hours. Randomization to hs-report format did not alter the admission rate (hs-report: 57.7% versus std-report: 58.0%; P=0.069). There was no difference in angiography (hs-report: 11.9% versus std-report: 10.9%; P=0.479). The hs-reporting did not reduce 12-month death or new/recurrent acute coronary syndrome in the overall population (hs-report: 9.7% versus std-report: 7.2% [hazard ratio, 0.83 (0.57–1.22); P=0.362]). However, among those with troponin levels <30 ng/L, a modest reduction in the primary end point was observed (hs-report: 2.6% versus std-report: 4.4%, [hazard ratio, 0.58; 95% confidence interval, 0.34–0.1.00; P=0.050). Conclusions—High-sensitivity troponin reporting alone is associated with only modest changes in practice. Clinical effectiveness in the adoption of high-sensitivity troponin may require close coupling with protocols that guide interpretation and care. Clinical Trial Registration—URL: http://www.ANZCTR.org.au. Unique identifier: ACTRN12611000879965.

Cost effectiveness of high-sensitivity troponin compared to conventional troponin among patients presenting with undifferentiated chest pain: A trial based analysis

BACKGROUND Patients with low and intermediate risk chest pain features comprise the greatest proportion presenting to emergency services for evaluation of suspected acute coronary syndromes (ACS). The efficient and timely identification of patients with these features remains a major challenge within clinical practice. Troponin assays are increasingly being used for the determination of risk among patients presenting with chest pain potentially facilitating more appropriate care. To date, no economic evaluation comparing high-sensitivity troponin T (hs-TnT) reporting to standard troponin T (c-TnT) reporting in the routine management of suspected ACS and based on longer-term clinical outcomes has been conducted. METHODS AND RESULTS An economic evaluation was conducted with 1937 participants randomized to either hs-TnT (n=973) or c-TnT (n=964) with 12month follow-up. The primary outcome measure was the number of cumulative combined outcomes of all-cause mortality and new or recurrent ACS avoided. Mean per participant Australian Medicare costs were higher in the hs-TnT arm compared to the c-TnT arm (by

Variation in Clinical Practice: A Priority Setting Approach to the Staged Funding of Quality Improvement

1285/patient). Mean total adverse clinical outcomes avoided were higher in the hs-TnT arm (by 0.0120/patient) resulting in an incremental cost-effectiveness ratio (ICER) of

Prognostic impact of moderate or severe mitral regurgitation (MR) irrespective of concomitant comorbidities: a retrospective matched cohort study

108,552/adverse clinical outcome avoided. An ICER of

Patterns of inflammatory activation associated with precipitants of acute coronary syndromes: a case‐crossover study

49,030/adverse clinical outcome avoided was obtained when the analysis was restricted to patients below the threshold of normal Troponin testing (actual c-TnT levels <30ng/L). CONCLUSIONS hs-TnT reporting leads to fewer adverse clinical events but at a high ICER. For the routine implementation of hs-TnT to be more cost-effective, substantial changes in clinical practice will be required. CLINICAL TRIAL REGISTRATION Australian New Zealand Clinical Trials Registry (ACTRN12614000189628). https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=365726.

Rational clinical evaluation of suspected acute coronary syndromes: The value of more information

Variation in adherence to clinical guidelines, and in the organisation and delivery of health care significantly impact patient outcomes and health service costs. Despite mounting evidence of variation in clinical practice, the funds allocated to improve the quality of existing services remain small, relative to the resources allocated to new technologies. Quality improvement is a complex intervention, with a lack of focus on outcomes, and greater uncertainty around its effects. These factors have contributed to a relatively narrow, mainstream view of quality improvement as focussing on safety, with efforts to improve adherence to best practice limited to high profile clinical areas. This paper presents an analysis of linked, routinely collected data to identify variation in patient outcomes and processes of care across hospitals for patients presenting with low-risk chest pain. Such analyses provide a low cost, broadly applicable approach to identifying potentially important areas of variation in clinical practice, to inform the prioritisation of more detailed analyses to validate, and further investigate the causes of variation.

Variation in coronary angiography rates in Australia: correlations with socio-demographic, health service and disease burden indices

Objective We sought to objectively quantify the independent impact of significant mitral regurgitation (MR) on prognosis in patients with multiple comorbidities and ascertain the extent to which median survival is affected by increasing comorbidities. Methods This was a retrospective matched cohort study using a clinical-echocardiography reporting database linked to a clinical and administrative database in an Australian tertiary hospital. We identified our study cohort (patients with significant MR) and control cohort (without MR) on transthoracic echocardiographies performed between 2005 and 2010. The main outcome measures were mortality and heart failure rehospitalisation. A Cox proportional hazards model was used to adjust for clinical covariates and the ‘win ratio’ methodology was utilised to estimate the impact of MR on main outcomes. Results A total of 218 matched patients with and without significant MR were followed-up for 1 year. Significant MR was associated with an adjusted HR for mortality of 1.83 (95% CI 1.28 to 2.62, p<0.001). The win ratio for death and death or heart failure readmission was 0.57 (95% CI 0.40 to 0.78, p=0.0002) and 0.53 (95% CI 0.39 to 0.71, p<0.0001), respectively. Significant MR with left ventricular (LV) systolic dysfunction and age between 75 and 85 years were associated with a substantial reduction in median survival by 2.3 years. Significant MR with LV systolic dysfunction, age beyond 85 and advance comorbidities were associated with a lesser reduction in median survival by 0.2 years. Conclusions Significant MR in patients with multiple comorbidities leads to increase in death and heart failure rehospitalisation with reduced estimated median survival. However, its impact diminishes with increasing comorbidities.

The appropriateness of coronary investigation in myocardial injury and Type 2 myocardial infarction (ACT-2): A randomized trial design

We sought to assess a broad array of possible precipitants of acute coronary syndromes (ACS) and evaluate their association with detectable inflammatory activation.

Has invasive management for acute coronary syndromes become more ‘risk-appropriate’: pooled results of five Australian registries

Many meta‐analyses have provided synthesised likelihood ratio data to aid clinical decision‐making. However, much less has been published on how to safely combine clinical information in practice. We aimed to explore the benefits and risks of pooling clinical information during the ED assessment of suspected acute coronary syndrome.