Validation of NICE diagnostic guidance for rule out of myocardial infarction using high-sensitivity troponin tests.

OBJECTIVE: To validate the National Institute for Health and Care Excellence (NICE) recommended algorithms for high-sensitivity troponin (hsTn) assays in adults presenting with chest pain. METHODS: International post hoc analysis of three prospective, observational studies from tertiary hospital emergency departments. The primary endpoint was cardiac death or acute myocardial infarction (AMI) within 24 hours of presentation, and the secondary endpoint was major adverse cardiac events (MACE) at 30 days. RESULTS: 15% of patients were diagnosed with non-ST elevation myocardial infarction (MI) on admission. The hsTnI algorithm classified 2506/3128 (80.1%) of patients as 'ruled out' with 50 (2.0%) missed MI. 943/3128 (30.1%) of patients had a troponin I level below the limit of detection on admission with 2 (0.2%) missed MI. For the hsTnT algorithm, 1794/3374 (53.1%) of patients were 'ruled out' with 7 (0.4%) missed MI. 490/3374 (14.5%) of patients had a troponin T below the limit of blank on admission with no MI. MACE at 30 days occurred in 10.7% and 8.5% of patients 'ruled out' defined by the hsTnI and hsTnT algorithms, respectively. CONCLUSIONS: The NICE algorithms could identify patients with low probability of AMI within 2 hours; however, neither strategy performed as predicted by the NICE diagnostic guidance model. Additionally, the rate of MACE at 30 days was sufficiently high that the algorithms should only be used as one component of a more extensive model of risk stratification. TRIAL REGISTRATION NUMBER: ACTRN12611001069943, NCT00470587; post-results.

The potential role of anticoagulant therapy for the secondary prevention of ischemic events post-acute coronary syndrome.

Abstract The use of dual antiplatelet therapy has led to a substantial reduction in ischemic events post-acute coronary syndrome (ACS). Despite this, recurrent event rates remain high. Recent research has combined antiplatelet with anticoagulant therapy to reduce recurrent event rates further. Compared with standard medical therapy, rivaroxaban demonstrated improved efficacy outcomes and significantly reduced mortality after an ACS. Although clear benefits of novel oral anticoagulants post-ACS have been proven, concerns regarding bleeding are still a barrier to widespread use. This review explores key trials of dual antiplatelet therapy and examines the latest research in anticoagulation aiming to optimize clinical outcomes post-ACS.

Lack of association between baseline plasma homocysteine concentrations and restenosis rates after a first elective percutaneous coronary intervention without stenting.

OBJECTIVE: To evaluate the association between baseline homocysteine concentrations and restenosis rates in patients electively undergoing their first percutaneous coronary intervention (PCI) without stenting. DESIGN: Prospective, single centre, observational study. SETTING AND PATIENTS: Patients electively undergoing their first PCI without stenting at a tertiary referral centre between 1990 and 1998. METHODS: Blood samples were collected from all patients at baseline and assayed to determine the patients' homocysteine concentrations. Patients whose PCI was successful underwent repeat angiography at a median of 6.4 (interquartile range 6-6.8) months. Their baseline and follow up angiograms were compared by quantitative coronary angiography to assess the incidence of restenosis. For the analysis, the patients were divided into two groups based on whether their baseline homocysteine concentrations were above or below the median value. These two groups were compared to determine whether there was any association between their baseline homocysteine concentrations and the incidence of restenosis at six months. RESULTS: 134 patients had a successful first PCI without stenting (involving 200 lesions). At six month angiography, restenosis was observed in 33 patients (49.3%) with baseline homocysteine concentrations above the median value and in 31 patients (46.3%) with concentrations below the median value (p = 0.74). There was no difference in the percentage of lesions developing restenosis (38 (39.6%) v 40 (38.5%), respectively, p = 0.87) or late lumen loss (0.40 mm v 0.31 mm, respectively, p = 0.24). On multivariable analysis, there was no association between homocysteine concentrations and late lumen loss (r = -0.11, p = 0.11) or the percentage diameter stenosis at follow up (r = -0.07, p = 0.32). CONCLUSION: Baseline homocysteine concentrations were not associated with six month restenosis rates in patients electively undergoing their first PCI without stenting.

Gelfoam embolization of a distal coronary artery guidewire perforation.

A guidewire-induced distal coronary artery perforation presenting with cardiac tamponade was occluded by distal Gelfoam embolization via an infusion catheter. This extends the treatment options for this rare complication of coronary interventional procedures. Cathet. Cardiovasc. Intervent. 49:214-217, 2000.