Appropriate use of serum troponin testing in general practice: a narrative review.

The troponin assay was designed to assist in diagnosis and improve risk stratification for people presenting to the emergency setting with symptoms suggestive of an acute coronary syndrome. Newly developed high sensitivity assays provide reliable detection of very low concentrations of troponin and offer earlier risk stratification of patients with possible acute coronary syndrome. Cardiac troponin testing in general practice should be limited to patients presenting with ischaemic symptoms that occurred more than 24 hours previously. If these patients have no high risk clinical features and a normal electrocardiogram (ECG), they may be assessed with a single troponin assay but should be referred urgently to hospital if the result is elevated. In patients presenting with symptoms of possible acute coronary syndrome within the preceding 24 hours, or if they otherwise have symptoms consistent with unstable angina, high risk clinical features or ECG abnormalities, a serum troponin test should not be ordered and patients should be referred immediately to an emergency department. When a single troponin assay is appropriate, the test should be labelled as urgent and systems must be in place to ensure the result is conveyed immediately to the medical practitioner, as it has prognostic implications and may require an urgent action plan.

Routine invasive strategies versus selective invasive strategies for unstable angina and non-ST elevation myocardial infarction in the stent era.

BACKGROUND: People with unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) are managed with a combination of medical therapy, invasive angiography and revascularisation. Specifically, two approaches have evolved: either a 'routine invasive' strategy whereby all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularisation; or a 'selective invasive' (also referred to as 'conservative') strategy in which medical therapy alone is used initially, with a selection of patients for angiography based upon evidence of persistent myocardial ischaemia. Uncertainty exists as to which strategy provides the best outcomes for these patients. This Cochrane review is an update of a Cochrane review originally published in 2006, to provide a robust comparison of these two strategies in the early management of patients with UA/NSTEMI. OBJECTIVES: To determine the benefits and harms associated with the following.1. A routine invasive versus a conservative or 'selective invasive' strategy for the management of UA/NSTEMI in the stent era.2. A routine invasive strategy with and without glycoprotein IIb/IIIa receptor antagonists versus a conservative strategy for the management of UA/NSTEMI in the stent era. SEARCH METHODS: We searched the following databases and additional resources up to 25 August 2015: the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library, MEDLINE and EMBASE, with no language restrictions. SELECTION CRITERIA: We included prospective randomised controlled trials (RCTs) that compared invasive with conservative or 'selective invasive' strategies in participants with acute UA/NSTEMI. DATA COLLECTION AND ANALYSIS: Two review authors screened the records and extracted data in duplicate. Using intention-to-treat analysis with random-effects models, we calculated summary estimates of the risk ratio (RR) with 95% confidence intervals (CIs) for the primary endpoints of all-cause death, fatal and non-fatal myocardial infarction (MI), combined all-cause death or non-fatal MI, refractory angina and re-hospitalisation. We performed further analysis of included studies based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. We assessed the heterogeneity of included trials using Pearson χ² (Chi² test) and variance (I² statistic) analysis. Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, we assessed the quality of the evidence and the GRADE profiler (GRADEPRO) was used to import data from Review Manager 5.3 (Review Manager) to create Summary of findings (SoF) tables. MAIN RESULTS: Eight RCTs with a total of 8915 participants (4545 invasive strategies, 4370 conservative strategies) were eligible for inclusion. We included three new studies and 1099 additional participants in this review update. In the all-study analysis, evidence did not show appreciable risk reductions in all-cause mortality (RR 0.87, 95% CI 0.64 to 1.18; eight studies, 8915 participants; low quality evidence) and death or non-fatal MI (RR 0.93, 95% CI 0.71 to 1.2; seven studies, 7715 participants; low quality evidence) with invasive strategies compared to conservative (selective invasive) strategies at six to 12 months follow-up. There was appreciable risk reduction in MI (RR 0.79, 95% CI 0.63 to 1.00; eight studies, 8915 participants; moderate quality evidence), refractory angina (RR 0.64, 95% CI 0.52 to 0.79; five studies, 8287 participants; moderate quality evidence) and re-hospitalisation (RR 0.77, 95% CI 0.63 to 0.94; six studies, 6921 participants; moderate quality evidence) with routine invasive strategies compared to conservative (selective invasive) strategies also at six to 12 months follow-up.Evidence also showed increased risks in bleeding (RR 1.73, 95% CI 1.30 to 2.31; six studies, 7584 participants; moderate quality evidence) and procedure-related MI (RR 1.87, 95% CI 1.47 to 2.37; five studies, 6380 participants; moderate quality evidence) with routine invasive strategies compared to conservative (selective invasive) strategies.The low quality evidence were as a result of serious risk of bias and imprecision in the estimate of effect while moderate quality evidence was only due to serious risk of bias. AUTHORS' CONCLUSIONS: In the all-study analysis, the evidence failed to show appreciable benefit with routine invasive strategies for unstable angina and non-ST elevation MI compared to conservative strategies in all-cause mortality and death or non-fatal MI at six to 12 months. There was evidence of risk reduction in MI, refractory angina and re-hospitalisation with routine invasive strategies compared to conservative (selective invasive) strategies at six to 12 months follow-up. However, routine invasive strategies were associated with a relatively high risk (almost double the risk) of procedure-related MI, and increased risk of bleeding complications. This systematic analysis of published RCTs supports the conclusion that, in patients with UA/NSTEMI, a selectively invasive (conservative) strategy based on clinical risk for recurrent events is the preferred management strategy.

Factors Contributing to Acute Kidney Injury and the Impact on Mortality in Patients Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) patients are at a high risk of acute kidney injury (AKI). This study aimed to investigate AKI and the relationship with iodinated contrast media (ICM), whether there are significant pre- or peri- procedural variables predicting AKI, and whether AKI impacts on hospital length of stay and mortality. METHODS: Serum creatinine (SC) levels pre- and post- (peak) TAVR were recorded in 209 consecutive TAVR patients. AKI was defined by the Valve Academic Research Consortium 2 (VARC2) criteria. Baseline characteristics, procedural variables, hospital length of stay (LOS) and mortality at 72hours, 30 days and one year were analysed. RESULTS: Eighty-two of 209 (39%) patients suffered AKI. Mean ICM volume was 228cc, with no difference between patients with AKI and those with no AKI (227cc (213-240(95%CI)) vs 231cc (212-250) p=0.700)). Univariate and multivariate analysis demonstrated that chronic kidney disease, respiratory failure, previous stroke, the need for blood transfusion and valve repositioning were all predictors of AKI. Acute kidney injury increased LOS (5.6 days (3.8 - 7.5) vs 3.2 days (2.6 - 3.9) no AKI (P=0.004)) but was not linked to increased mortality. Mortality rates did increase with AKI severity. CONCLUSION: Acute kidney injury is a common complication of TAVR. The severity of AKI is important in determining mortality. Acute kidney injury appears to be independent of ICM use but pre-existing renal impairment and respiratory failure were predictors for AKI. Transcatheter aortic valve replacement device repositioning or retrieval was identified as a new risk factor impacting on AKI.

Transcatheter valve-in-valve replacement of degenerated bioprosthetic aortic valves: a single Australian Centre experience.

BACKGROUND: Patients with degenerated surgical bioprosthetic valves may be at high risk for further surgery because of age, comorbidities and the difficulties of repeat procedures. Percutaneous valve-in-valve implantation offers what may be a simpler and safer procedure. METHODS: From May 2009 to March 2014 at the Prince Charles Hospital 1625 patients underwent surgical aortic valve replacement while 262 underwent transcatheter aortic valve implantation. Twelve patients had valve-in-valve implants for degenerated bioprosthetic aortic valves. RESULTS: These implants were deployed successfully without major valvular or paravalvular regurgitation. There were no periprocedural deaths, myocardial infarcts, neurological events or major vascular complications. Two patients died after 1624 and 1319days. Median survival for the remainder is 581days; they are stable with New York Heart Association class I/II functional status although 4 have a degree of patient-prosthesis mismatch, one has moderate aortic regurgitation and one required surgery for a late aortic dissection. CONCLUSION: Transcatheter valve-in-valve implantation is safe and effective treatment for patients with failed bioprosthetic aortic valves for whom reoperation is considered to be hazardous.

Using DynaCT for the assessment of ilio-femoral arterial calibre, calcification and tortuosity index in patients selected for trans-catheter aortic valve replacement.

Adequate vascular access for femoral trans-catheter aortic valve replacement is fundamental to the success of the procedure. Assessment of vascular calibre, tortuosity and calcification is performed by angiography and multi-slice computed tomography (MSCT). Can DynaCT provide the same information as MSCT? 15 Patients underwent MSCT, angiography and DynaCT. Vessel diameter measurements were taken in three positions of the left and right ilio-femoral arteries. Tortuosity was assessed using an index of the direct distance and the distance taken by the artery between two points. Calcification was assessed in MSCT and DynaCT using a simple scoring system. Concordance correlation coefficient of arterial calibre between angiography and MSCT was 0.96 (95 % CI 0.94-0.97). DynaCT and angiography was 0.94 (95 % CI 0.91-0.96) and Dyna CT and MSCT, 0.95 (95 % CI 0.92-0.97). Bland-Altman tests demonstrate a mean difference between the angiogram and the MSCT of 0.06 mm (+0.97, -1.42), angiogram and DynaCT, 0.13 mm, (+1.00, -0.87), DynaCT and MSCT, 0.2 mm, (+1.15, -0.76). Tortuosity comparisons gave a median tortuosity index for MSCT 1.29 and DynaCT 1.23 (p = 0.472). Calcification comparisons of MSCT and DynaCT using correlation coefficients demonstrate a correlation of 0.245 (p = 0.378). Effective radiation doses were: DynaCT; 3.63 ± 0.65 mSv and angiography; 0.57 ± 0.72 mSv, MSCT; 7.15 ± 2.58 mSv. DynaCT is equal to MSCT and angiography in assessing femoral artery calibre. Like MSCT, it can assess tortuosity and can produce 3D images but is inferior in the assessment of calcification.

Early experience of transaortic TAVI--the future of surgical TAVI?

BACKGROUND: Trans-catheter aortic valve implantation (TAVI) is now a well recognised procedure for the high risk surgical patient with native or bioprosthetic aortic valve stenosis. Transfemoral and transapical implantation techniques are well described. With increasing referral of more marginal transapical patients, we describe our experience of a transaortic TAVI approach which we believe reduces the postoperative wound pain, respiratory complications, operative risk and hospital stay. METHODS: Patients referred for surgical TAVI underwent trans-catheter aortic valve implantation via an upper sternotomy and direct cannulation of the ascending aorta. RESULTS: Thirteen patients with a mean age of 81 years underwent transaortic Edwards SAPIEN valve implantation. There was no in hospital mortality in our series. One patient required insertion of a permanent pacemaker for complete heart block. There were no aortic cannulation complications. CONCLUSION: The transaortic TAVI approach provides good exposure of the distal ascending aorta, a familiar cannulation site for cardiac surgeons. Our initial experience demonstrates the approach to be a safe technique with the potential for faster and less complicated recovery in patients undergoing surgical TAVI procedures. With further experience and greater acceptance, the transaortic approach may ultimately become the procedure of choice for patients unsuitable for a transfemoral approach.

Impact of optimising fluoroscopic implant angles on paravalvular regurgitation in transcatheter aortic valve replacements - utility of three-dimensional rotational angiography.

AIMS: The clinical value of optimising implant angles during transcatheter aortic valve replacements (TAVR) remains undefined. The Aortic Valve Guide (AVG) is a proprietary software that provides structured analysis of three-dimensional images from rotational angiography (DynaCT). This study compares AVG with preprocedural multislice computed tomography (MSCT) and DynaCT in optimal implant angle prediction for TAVR, and evaluates if an optimised implant angle is associated with reduced paravalvular regurgitation (PVR). METHODS AND RESULTS: One hundred and six consecutive patients were included, comprising three groups. Group 1 (n=19) underwent no preprocedural MSCT or DynaCT (or AVG); Group 2 (n=44) underwent periprocedural DynaCT, without AVG; Group 3 (n=43) had DynaCT with AVG. Implant angles yielded were graded as excellent, satisfactory or poor. Group 3 were more likely than Groups 2 and 1 to have excellent implant angles (83.7% vs. 52.3% vs. 42.1%, respectively, p=0.001). In 100 patients who had 30-day transthoracic echocardiogram follow-up, an excellent implant angle was significantly more likely to be associated with no PVR than a non-excellent angle (41.3% vs. 21.6%, respectively, p=0.045), independent of operator experience and THV used. CONCLUSIONS: Optimising implant angles may be important in reducing PVR. This is significantly more likely to be achieved with AVG rotational angiography.

First Australian transapical mitral valve-in-valve implant for a failed mitral bioprosthesis: how to do it.

Transcatheter aortic valve replacements lower mortality in patients not suitable for surgical valve replacement compared to conservative treatment. Transcatheter valve-in-valve implants have been shown to be feasible in failed bioprostheses in aortic, mitral, pulmonary and tricuspid positions. We report the first Australasian experience of a transapical mitral valve-in-valve placement with an Edwards Sapien(®) transcatheter valve for a failed mitral bioprosthesis, focussing on the technical aspects of this novel procedure. Whilst the evidence for this niche indication is limited currently to case reports and case series, further evaluation of its long term outcomes may justify its use in this particularly high risk group of re-do sternotomy patients.

A suggested paradigm for coronary risk screening in asymptomatic persons--assessment of total coronary atheromatous burden.

Coronary risk factors are poor at predicting adverse cardiac events in the individual patient, with more than 75% of all hard coronary events occurring in persons classified as low or intermediate risk. Myocardial ischaemia testing of asymptomatic persons is an inappropriate measure of myocardial infarction risk, and is plagued by a preponderance of false positive and false negative tests. Total coronary atheromatous burden as measured by non-invasive CT coronary calcium scoring, may provide the best contemporary measure of coronary risk, and offer a rational cost-effective approach to long-term management.

Early invasive versus conservative strategies for unstable angina and non-ST elevation myocardial infarction in the stent era.

BACKGROUND: In patients with unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) two strategies are possible, either a routine invasive strategy where all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularization; or a conservative strategy where medical therapy alone is used initially, with selection of patients for angiography based on clinical symptoms or investigational evidence of persistent myocardial ischemia. OBJECTIVES: To determine the benefits of an invasive compared to conservative strategy for treating UA/NSTEMI in the stent era. SEARCH STRATEGY: The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 1), MEDLINE and EMBASE were searched (1996 to February 2008) with no language restrictions. SELECTION CRITERIA: Included studies were prospective trials comparing invasive with conservative strategies in UA/NSTEMI. DATA COLLECTION AND ANALYSIS: We identified five studies (7818 participants). Using intention-to-treat analysis with random-effects models, summary estimates of relative risk (RR) with 95% confidence interval (CI) were determined for primary end-points of all-cause death, fatal and non-fatal myocardial infarction, all-cause death or non-fatal myocardial infarction, and refractory angina. Further analysis of included studies was undertaken based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. Heterogeneity was assessed using Chi(2) and variance (I(2) statistic) methods. MAIN RESULTS: In the all-study analysis, mortality during initial hospitalization showed a trend to hazard with an invasive strategy (RR 1.59, 95% CI 0.96 to 2.64). The invasive strategy did not reduce death on longer-term follow up. Myocardial infarction rates assessed at 6 to 12 months (5 trials) and 3 to 5 years (3 trials) were significantly decreased by an invasive strategy (RR 0.73, 95% CI 0.62 to 0.86; and RR 0.78, 95% CI 0.67 to 0.92 respectively). The incidence of early (< 4 month) and intermediate (6 to 12 month) refractory angina were both significantly decreased by an invasive strategy (RR 0.47, 95% CI 0.32 to 0.68; and RR 0.67, 95% CI 0.55 to 0.83 respectively), as were early and intermediate rehospitalization rates (RR 0.60, 95% CI 0.41to 0.88; and RR 0.67, 95% CI 0.61 to 0.74 respectively). The invasive strategy was associated with a two-fold increase in the RR of peri-procedural myocardial infarction (as variably defined) and a 1.7-fold increase in the RR of (minor) bleeding with no hazard of stroke. AUTHORS' CONCLUSIONS: Compared to a conservative strategy for UA/NSTEMI, an invasive strategy is associated with reduced rates of refractory angina and rehospitalization in the shorter term and myocardial infarction in the longer term. However, the invasive strategy is associated with a doubled risk of procedure-related heart attack and increased risk of bleeding and procedural biomarker leaks. Available data suggest that an invasive strategy may be particularly useful in those at high risk for recurrent events.

Acute coronary syndromes: consensus recommendations for translating knowledge into action.

A systematic, integrated national approach is needed to implement 2006 Australian guidelines for management of acute coronary syndromes (ACS). Clinical outcomes can be improved by closing the current gaps between evidence and practice. In 2007, the National Heart Foundation of Australia, the Cardiac Society of Australia and New Zealand, and the Australasian College for Emergency Medicine held a national forum to identify current gaps in ACS management and priority strategies to improve outcomes. Consensus recommendations were based on evidence and expert opinion. Prompt reperfusion for patients with ST-segment-elevation myocardial infarction should be ensured by establishing protocols for single-call activation of primary percutaneous coronary intervention, or, where unavailable, enabling health care workers to initiate thrombolysis. Accuracy of risk stratification of non-ST-segment-elevation ACS (NSTEACS) should be improved using clinical pathways that integrate ambulance, medical and nursing care. Rates of early invasive management for patients with high-risk NSTEACS should be increased using efficient systems for transfer to revascularisation facilities. All patients with an ACS should be referred to rehabilitation and secondary prevention programs, including alternative models of care where appropriate. Equal access to recommended care for all Australians with an ACS - including those in rural, remote and Aboriginal and Torres Strait Islander communities - should be achieved by improving workforce capacity in under-resourced regions and ensuring access to third-generation fibrinolytic agents, defibrillation, timely essential pathology tests and invasive revascularisation facilities. National standards for data collection and clinical outcomes should be established, and performance should be monitored.

Early and late cardiac perforation by Amplatzer atrial septal defect and patent foramen ovale devices.

Cardiac perforation and device erosion are infrequent but potentially lethal complications of percutaneous occluder device insertion. Transthoracic and transesophageal echocardiography (TEE) and gated cardiac computed tomography are useful in detecting this complication. In particular, TEE can detect characteristic features to confirm the diagnosis before rapid surgical correction. Deficient superior-anterior rim and encroachment of the occluder device on the posterior atrial wall are risk factors for device erosion. TEE performed before device insertion with awareness of manufacturer's guidelines for atrial geometry and device sizing may reduce the occurrence of this serious complication.

2007 addendum to the National Heart Foundation of Australia/Cardiac Society of Australia and New Zealand Guidelines for the management of acute coronary syndromes 2006.

Results from recently published clinical trials provide additional information to be considered in the choice of therapies in the management of acute coronary syndromes. This addendum summarises the important findings and their implications for recommended practice.

Variations in the application of cardiac care in Australia.

OBJECTIVE: To evaluate the use of clinical practice guidelines for the management of acute coronary syndromes published by the National Heart Foundation (NHF) of Australia and the Cardiac Society of Australia and New Zealand (CSANZ) in patients presenting with chest pain. DESIGN: Cross-sectional study of consecutive patients admitted with chest pain. SETTING: Prospective case note review was undertaken in 2380 patients admitted to 27 hospitals across five states in Australia between January 2003 and August 2005. Patients were divided into two groups: those who presented to centres with angiography and percutaneous intervention facilities (n = 1260) and those treated at centres without these facilities (n = 1120). MAIN OUTCOME MEASURES: The proportion of patients whose care met quality of care standards for diagnostic and risk-stratification procedures and management according to NHF/CSANZ treatment guidelines. RESULTS: Significant delays were identified in performing electrocardiography, administering thrombolysis, transferring high-risk patients to tertiary centres, and performing revascularisation. Medical therapy was underused, especially glycoprotein IIb/IIIa antagonists in patients with high-risk acute coronary syndromes. Patients treated at centres without interventional facilities were less likely to receive guidelines-based medical therapy and referral for coronary angiography (20.11%) than patients treated at centres with interventional facilities (66.43%; P < 0.001). CONCLUSION: There are deficits in the implementation and adherence to evidence-based guidelines for managing chest pain in hospitals across Australia, and significant differences between hospitals with and without interventional facilities.

Measurement of myocardial fractional flow reserve is a cost-effective way to identify coronary artery lesions of indeterminate severity that warrant revascularisation.

BACKGROUND: The RADI pressure wire may be used in stenotic coronary arteries to calculate myocardial fractional flow reserve (FFR(myo)), the ratio between distal hyperaemic coronary pressure and aortic pressure. A ratio less than 0.75 categorizes lesions of haemodynamic significance for which percutaneous coronary intervention (PCI) or coronary artery bypass surgery (CABG) may be warranted. We undertook this study to evaluate the cost implications of performing these measurements. METHODS: We recorded FFR(myo) using RADI wires in 32 coronary artery lesions of between 30 and 60% diameter stenosis in 31 patients and assessed how this information changed our management. RESULTS: We followed our original "management plan" in only eight patients. PCI or CABG was performed in eight whose lesions were characterised by a FFR(myo) value of 0.76 or less. Myocardial perfusion imaging (MPI) was done in only one of nine for whom this had seemed to be appropriate. Two-thirds of those for whom PCI had appeared to be warranted were treated conservatively and only one quarter of the original "surgical" group underwent CABG. CONCLUSION: Although RADI pressure wires are an additional expense, it is appropriate to use them to assess coronary stenotic lesions of indeterminate severity. When we took into account the savings that arose from changes in management, the additional cost of measuring FFR(myo) was around dollar 580 per study.

National data elements for the clinical management of acute coronary syndromes.

Patients with acute coronary syndromes represent a clinically diverse group and their care remains heterogeneous. These patients account for a significant burden of morbidity and mortality in Australia. Optimal patient outcomes depend on rapid diagnosis, accurate risk stratification and the effective implementation of proven therapies, as advocated by clinical guidelines. The challenge is in effectively applying evidence in clinical practice. Objectivity and standardised quantification of clinical practice are essential in understanding the evidence-practice gap. Observational registries are key to understanding the link between evidence-based medicine, clinical practice and patient outcome. Data elements for monitoring clinical management of patients with acute coronary syndromes have been adapted from internationally accepted definitions and incorporated into the National Health Data Dictionary, the national standard for health data definitions in Australia. Widespread use of these data elements will assist in the local development of "quality-of-care" initiatives and performance indicators, facilitate collaboration in cardiovascular outcomes research, and aid in the development of electronic data collection methods.