COMPARISON OF HEPARIN-THERAPY FOR LESS-THAN-OR-EQUAL-TO-48 HOURS TO GREATER-THAN-48 HOURS UNSTABLE ANGINA-PECTORIS

Of 450 consecutive patients with unstable angina admitted ta a tertiar y care, university-based medical center over a 24-month period, 334 we re administered heparin and aspirin for some length of time. Two group s of 98 patients matched far acuity and gender at baseline were treate d with either less than or equal to 48 hours (group 1) or >48 hours (g roup 2) of heparin. The acuity model used in this study incorporates 6 factors: age, recent myocardial infarction, treatment with intravenou s nitroglycerin, previous therapy with beta blockers or calcium antago nists, baseline ST depression, and diabetes. Despite similar risks and overall clinical outcome, group 2 had significantly more myocardial i nfarction or death after 48 hours than group 1 (p = 0.01). In part, th is was due to a delay in the performance of coronary angiography (2.8 +/- 1.4 vs 3.5 +/- 15 days, p = 0.01), coronary intervention (2.7 +/- 1.8 vs 5.1 +/- 2.3 days, p = 0.01), and bypass surgery (3.8 +/- 3.6 vs 7.0 +/- 5.6 days, p = 0.02). There was no difference between groups r egarding the success of coronary intervention (90% vs 88%, p = NS). He parin duration was influenced by the finding of intracoronary thrombus or ulceration on angiography before revascularization, as each findin g was seen more often in group 2 (thrombus, 12% vs 24%; ulceration, 38 % vs 60%). These results suggest that the optimal duration of heparin therapy is up to 48 hours after admission in unstable angina; a longer time period is associated with increased adverse consequences. (C) 19 97 by Excerpta Medica, Inc.