Risk stratification, management and outcomes of patients with non-ST elevation acute coronary syndrome: a Canadian teaching hospital perspective

Abstract

Background: Current guidelines for non-ST elevation acute coronary syndromes (NSTACS) recommend tailoring the intensity of therapeutic management according to the baseline risk of the patient. Although the clinical characteristics, risk stratification and therapeutic management of contemporary patients with NSTACS have been reported for other geographical regions, this information has not been documented from a Canadian perspective.

Objectives: To describe the baseline clinical characteristics, therapeutic management and clinical outcomes of contemporary patients with NSTACS at a Canadian, tertiary care, teaching hospital, and to retrospectively risk stratify the patients with NSTACS according to the American College of Cardiology (ACC)/American Heart Association (AHA) and Thrombolysis in Myocardial Infarction (TIMI) risk guidelines to characterize management and outcomes according to the various risk classifications.

Methods: Baseline demographics, procedural variables and clinical outcome data were retrospectively collected in 380 patients with a diagnosis of NSTACS from July 1999 to July 2000. Patients were retrospectively categorized into high, intermediate and low risk categories using two classification schemes.

Results: According to the ACC/AHA guidelines, 10.3% and 89.7% of patients were intermediate and high risk, respectively. Applying the TIMI risk score, 20.0%, 52.4% and 27.6% of patients were low, intermediate and high risk, respectively. The use of antithrombotic, acetylsalicylic acid and beta-blocker therapy was very high both in hospital and at discharge. Glycoprotein IIb/IIIa inhibitors, angiotensin-converting enzyme inhibitors and lipid lowering agents were all underutilized. The use of pharmacological therapies and cardiovascular interventions did not appear to correlate with the level of risk of the patient, at least within these classification schemes. Adverse clinical events in hospital and length of hospital stay increased as the risk level of the patients increased.

Conclusions: According to the ACC/AHA guidelines, patients with a discharge diagnosis of NSTACS in a nontrial setting are a high risk population, requiring prompt recognition and aggressive management. This study serves as an integral part of clinical practice to continually evaluate the quality of medical care.