Faculty Bibliography

The risk of death or recurrent myocardial infarction (MI) in patients with chest pain and baseline isolated troponin elevation is unclear. To determine the early and short-term risk of death or MI associated with isolated troponin elevation across a spectrum of chest pain syndromes, we used baseline creatine kinase (CK)-MB and troponin data from the Platelet IIb/IIIa Antagonism for the Reduction of Acute Coronary Syndrome Events in a Global Organization Network (PARAGON) B troponin substudy, the Global Utilization of Strategies To Open Occluded Coronary Arteries (GUSTO) IIa troponin substudy, and the Chest Pain Evaluation by Creatine Kinase-MB, Myoglobin, and Troponin I (CHECKMATE) study. Patients were grouped into 1 of 4 categories based on marker status (troponin-positive/CK-MB-positive, troponin-positive/CK-MB-negative, troponin-negative/CK-MB-positive, or troponin-negative/CK-MB-negative). The adjusted odds of death or MI occurring at 24 hours and 30 days was assessed by baseline marker status using multivariable logistic regression, with the group negative for both markers used as the reference. Patients who were positive for both markers had the highest odds of the 24-hour and 30-day end point. The adjusted odds of the 30-day end point for patients with isolated troponin elevation were 1.3 (95% confidence interval 0.7 to 2.3) and 4.8 (95% confidence interval 1.4 to 16.0) for high- and low-risk patients, respectively. The risk for 24-hour and 30-day death or MI with isolated positive CK-MB results was lower than with isolated positive troponin results, and it was not significantly greater than if the 2 markers were negative. For patients with high- and low-risk chest pain, baseline troponin elevation without CK-MB elevation was associated with increased risk for early and short-term adverse outcomes. This suggests that these patients should be admitted to the hospital and monitored in either an intensive care or step-down unit.

Quality assurance and improvement have increasingly been the focus of health care providers, third-party payers, and patients. Because cardiovascular procedures are common, easily identifiable with claims data, and account for a relatively large proportion of health care expenditures, particular attention has been paid to quality assurance in the setting of the diagnostic and interventional cardiac catheterization laboratory. The structure, process, and outcomes domains of quality measurement in the interventional laboratory involve the maintenance of volume standards, the availability of surgical backup, consistent tracking of procedural outcomes and complications so they can be compared with national standards, and the application of evidence-based therapy. Quality assurance i the diagnostic laboratory revolves around the clinical proficiency of the operators, the maintenance and management of catheterization laboratory equipment, and the presence of a continuous quality improvement program. The evolution of interventional equipment and techniques along with the establishment of national registries has led to a gradual improvement in the quality of percutaneous coronary intervention. Given the dynamic nature of cardiology, adaptable quality assurance and quality improvement programs will remain the foundation of successful catheterization labs.