Introduction: Chest pain and symptoms of acute coronary syndrome are responsible for a large proportion of ED visits and acute hospitalizations. However, only about 15% of patients presenting to the ED with high-risk symptoms do, in fact, have an acute coronary syndrome. The objective of this study is to derive a 2-hour high-sensitivity Troponin T (hsTnT) testing algorithm with outcome based-cutoffs to rapidly rule out acute myocardial infarction (AMI) in a large proportion of ED chest pain patients. Methods: Patients included consecutive ED patients with a chief complaint of cardiac chest pain who had an hsTnT assay performed at ED arrival and 2 hours after ED arrival. Administrative databases were queried to identify troponin results and major adverse cardiac outcomes (MACE) including death, MI, and revascularization. Test characteristics of iterative combinations of initial troponin level and absolute change in troponin level were quantified in order to identify the testing algorithm that identified the greatest proportion of patients eligible for early discharge while maintaining a target sensitivity of 98.5% for the primary outcome of 7-day AMI. Results: 755 eligible patients had hsTnT assays performed at ED arrival and at 2 hours. 91 patients (12.1%) had a 7-day AMI while 108 (14.0%) had 7-day MACE. An initial hsTnT level of less than 14 ng/L, in combination with a 2-hour absolute change of less than 10ng/L had a sensitivity of 98.9% (95% CI 94.0,99.8) and an NPV of 99.8% (95% CI 98.7, 100.0) for 7-day AMI. This identified 58.5% of all patients as being suitable for early discharge. Sensitivity and NPV for 7-day MACE were 90.0% (95% CI 83.3, 94.2) and 97.3% (95% CI 95.3,98.4) respectively. Sex-specific differences in test characteristics were not clinically important. Rule-in hsTnT cutoffs were also evaluated, with specificities ranging from 85-95%, although cutoffs with higher specificity had less ability to rapidly rule-in AMI, leaving more patients with indeterminate results after 2 hours. Conclusion: A hsTnT algorithm can safely and accurately rule out AMI in 58.5% of ED chest pain patients within 2 hours of ED arrival. The lower sensitivity of this algorithm for MACE compared to AMI speaks to the importance of clinical assessment and ECG findings in identifying patients at risk for acute coronary syndromes.

Objectives: Implantable cardioverter defibrillator (ICD) therapy reduces the risk of sudden death in patients with ischemic cardiomyopathy, but their novelty and cost may represent barriers to utilization. The objective of this study was to examine the influence of age, gender, place of residence, and socioeconomic status on rates of ICD implantation for the primary prevention of death.

Methods: We conducted a population-based retrospective cohort study involving the entire province of Ontario, Canada. Patients were eligible if they had survived following hospitalization for heart failure from 1 January 1993, to 31 March 2004, and previously sustained an acute coronary syndrome within 5 years. Patients with an existing ICD or a documented history of cardiac arrest were excluded, as were patients who died in the hospital. Primary outcome was ICD implantation.

Results: We identified 48,426 patients hospitalized for heart failure who survived to hospital discharge. Of these, 440 received an ICD, with a gradual 30-fold increase in implantation rates over the study period (.12–3.9 percent). ICD recipients were more likely to be men (odds ratio [OR] = 4.14; 95 percent confidence interval [CI], 3.24–5.30), younger than 75 years of age (OR = 3.19; 95 percent CI, 2.57–3.96), reside in a metropolitan area (OR = 1.42; 95 percent CI, 1.04–1.9), and live in a higher socioeconomic neighborhood (OR = 1.32; 95 percent CI, 1.08–1.61).

Conclusions: Among patients with heart failure and a previous myocardial infarction, ICD use is increasing in Ontario. However, the application of this technology is characterized by major sociodemographic inequities. The causes and consequences of the pronounced age and gender discrepancies, in particular, warrant further investigation.

The diagnostic approach to acute coronary syndromes (ACS) remains one of the most difficult and controversial challenges facing emergency physicians. In recent years, cardiac troponins have emerged as the biochemical “gold standard” for diagnosis of patients with acute chest pain, enhancing our ability to recognize ACS. Early diagnosis and treatment of myocardial ischemia improve patient outcomes, but conventional markers are often nondiagnostic at the time of arrival at the emergency department. Promising new biomarkers, which appear earlier after the onset of ischemia, are being studied and integrated into clinical practice. Some are markers of myocyte necrosis, but others, including ischemia-modified albumin and natriuretic peptides, detect myocardial ischemia and myocardial dysfunction. The aim of the present article is to review the diagnostic approach to ACS, focusing on recent literature describing novel biochemical markers. If ongoing and future studies confirm their role in probability-based models risk assessment, a new era in the diagnostic approach to ACS may be dawning.

Despite major advances in the management of acute coronary syndromes (ACS), 1 in 3 Canadians die from cardiovascular disease. In 1998, the total economic burden of cardiovascular illness in Canada was $159 434.5 million dollars — $83 953.9 million in direct costs and $75 479.6 in indirect costs. During the past 20 years, several pharmacologic adjuncts have been investigated with hopes of ameliorating the consequences of ACS. Notably, clopidogrel has become a common component of ACS therapeutic regimens since its introduction in 1998. Both new medications and those already accepted as standard treatment deserve critical evaluation to ensure they are safe and effective.