Association of Unstable Angina Guideline Care With Improved Survival

BACKGROUND: An unstable angina guideline was published in 1994 by the Agency for Health Care Policy and Research, Bethesda, Md. However, the relationship between guideline-concordant care and patient outcomes is unknown. OBJECTIVE: To determine whether guideline-concordant care is associated with improved outcomes. METHODS: The study sample consisted of 275 consecutive nonreferral patients hospitalized with primary unstable angina. One-year survival and survival free of myocardial infarction were compared between patients who received care concordant with 8 selected guideline recommendations and patients who received discordant care. RESULTS: Care concordant with the 8 key guideline recommendations was associated with improved 1-year survival (95% vs 81%; log-rank P<.001) and survival free of myocardial infarction (91% vs 74%; P<.001), compared with guideline-discordant care. Patients in high-risk subgroups had the largest survival benefit associated with guideline-concordant care (aged -65 years, 91% vs 74% P=.005; heart failure at presentation, 91% vs 68% P=.10). Aspirin therapy was the single recommendation most strongly associated with improved 1-year survival (94% vs 78%; P=.002). CONCLUSIONS: Care as outlined in the unstable angina clinical practice guideline is associated with improved 1-year outcomes. Subgroups of patients at highest risk and recommendations firmly based on randomized clinical trial data were most strongly associated with better outcomes. These findings support the use of an evidence-based approach to guideline development and assessment of quality of care in patients with primary unstable angina.