RESUMO
BACKGROUND AND METHODS: Because time to presentation to the hospital affects time to treatment and is known to be important in acute myocardial infarction, we evaluated this variable in patients with unstable angina/non-ST segment elevation myocardial infarction (UA/NSTEMI). Among 2909 consecutive patients with UA/NSTEMI admitted to 35 hospitals in 6 geographic regions of the United States, we compared patients with acute (onset of pain <12 hours before admission) and subacute (onset >12 hours) unstable angina. RESULTS: Patients with "hot" (acute) unstable angina presented more often to the emergency department and were subsequently admitted more often to an intensive care unit. Hospital administration of medications did not differ between the two groups, with the exception of heparin, which was paradoxically used more often in subacute patients (p<0.001). All cardiac invasive procedures were undertaken less often in the acute patients (catheterization, 41.4% vs. 58.7%, p=0.001; percutaneous coronary intervention, 11.3% vs. 21.1%, p=0.001; coronary artery bypass grafting, 5.6% vs. 12.0%, p=0.001). A greater percentage of acute patients were found to have no significant coronary artery disease at cardiac catheterization (20.1% vs. 15.0%, p=0.006). Mortality did not differ between the two groups; however, the composite endpoint of death and MI favored the acute patients (1.3% vs. 2.2%, p=0.032). CONCLUSIONS: Contrary to our initial hypothesis, "hot" UA patients tended to be at lower risk than patients with subacute presentation, highlighting the fact that patients with UA/NSTEMI remain at high risk even after the initial 12-hour period.
