Clinical practice guidelines were established by the Agency for Health Care Policy and Research, which is now called the Agency for Healthcare Research and Quality, to improve the quality of care for patients with unstable angina. The implementation of these guidelines has been left to individual physicians and hospitals. Iliadis and associates assessed whether the use of these guidelines alters the care of patients with unstable angina.

Patients admitted to a tertiary care facility with unstable angina were included in the study. Two groups were identified: the patients in group 1 were admitted before the implementation of the guidelines for unstable angina, and the patients in group 2 were admitted after the guidelines were initiated. All patients with unstable angina who were rated as medium to high risk were included in the study. The guidelines include intravenous nitroglycerin for ongoing ischemia, intravenous heparin for all medium- to high-risk patients, and the use of aspirin and beta blockers in all cardiac patients. All of these interventions were used unless patients had contraindications for a medication. Outcome assessment included treatments rendered, procedures incurred by the group and major cardiac complications.

The two groups were similar in most baseline characteristics. Patients in group 2 were more likely to receive aspirin and intravenous nitroglycerin than patients in group 1. Patients in group 2 were also more likely to receive oral beta blockers, aspirin and coronary angiography earlier than the other group. Patients in group 2 were less likely to experience recurrent angina, myocardial infarction and death than group 1.

The authors conclude that clinical practice guidelines for unstable angina were associated with a greater use of therapeutic interventions and earlier administration of medications. Clinical outcomes improved with the implementation of these guidelines and improved the quality of care in patients with unstable angina.