PROSPECTIVE TEMPORAL ANALYSIS OF THE ONSET OF PREINFARCTION ANGINA VERSUS OUTCOME - AN ANCILLARY STUDY IN TIMI-9B

Background-The timing of onset of angina before myocardial infarction in relation to outcome is unknown. Methods and Results-We prospectivel y determined the importance of the time of onset of preinfarction angi na in relation to 30-day outcomes in the TIMI-9B study from standardiz ed forms. Of the 3002 patients entered into the study, 425 reported an gina before their myocardial infarction. Patients with angina onset wi thin 24 hours of infarction had a lower 30-day cardiac event rate (mor tality, recurrent myocardial infarction, heart failure, or shock) at 4 % than those with onset of angina >24 hours (17%; P=.030). A history o f any angina alone was not associated with reduced event rate. Peak cr eatine kinase levels tended to be lower in the group with angina withi n 24 hours, These benefits were not due to higher rates of use of anti anginal medicines or aspirin and were not a consequence of differences in baseline characteristics or disease states hypertension, hyperchol esterolemia) among subgroups. Conclusions-These temporal observations are consistent with the concept of preconditioning by preinfarction an gina but do not rule out other mechanisms.