Fig. 1

Change in mortality associated with time to fibrinolytic treatment [7] . All patients in the ASSET and Late Assessment of Thrombolytic Efficacy (LATE) studies were included because the tabular information available from these trials subdivided by delay was not subdivided by electrocardiogram results. BBB indicates bundle branch block. Adapted with permission from Lancet 1994;343:311-22.

Fig. 2

Change in mortality associated with medical contact-to-balloon time [10] . OR indicates odds ratio; CI, confidence interval. Adapted with permission from JAMA 2000;283:2941-47.

Fig. 3

“Lytic decision zones” for the emergency physician. The shaded boxes indicate the periods of unknown time delays during which a decision must be made about whether or not to administer a fibrinolytic. *ACC/AHA guidelines state that an invasive strategy is generally preferred for patients presenting more than 3 hours after symptom onset [1] .

Fig. 4

Absolute risk reduction in 4- to 6-week mortality with primary PCI as a function of PCI-related time delay [28] . Circle sizes reflect the sample sizes of individual studies included in the analysis. Values greater than 0 represent benefit and values less than 0 represent harm (indicating that fibrinolysis is favored). The solid line represents the weighted meta-regression analysis. Reprinted with permission from Am J Cardiol 2003;92:824-6 [28] .

Fig. 5

Hypothetical construct of the relationship among the time from onset of symptoms of acute MI to reperfusion therapy, mortality reduction, and extent of myocardial salvage [35] . The benefit of reperfusion therapy with regard to mortality is greatest in the first 2 to 3 hours after symptom onset, most likely a consequence of myocardial salvage. After this critical early period, the magnitude of the mortality benefit is much reduced, and as the mortality reduction curve flattens, time to reperfusion therapy is less critical. If a treatment strategy is able to move patients back up the curve, a benefit would be expected. The benefit of a shift from point A or B to point C would be substantial, but the benefit of a shift from point A to point B would be small. A treatment strategy that delays therapy during the early critical period, such as patient transfer for PCI, would be harmful (shift from point D to point C or point B). Reprinted with permission from JAMA 2005;293:979-86.