715-4 Thrombolytic Therapy During the “Golden Rrst Hour” in GUSTO

Data derived from thrombolytic trials performed during the placebocontrolled era have suggested that initiation of reperfusion therapy during the “golden first hour” after onset of infarction may dramatically reduce mortality and improve myocardial salvage. Pts presenting within 1 hr in these early studies may also have differed from those presenting later by having larger infarctions or more hemodynamic compromise; early therapy may thus compensate for the high-risk profile of these patients. To determine in a large contemporary cohort the extent to which early-treated pts differ with regard to baseline characteristics and clinical outcome from pts presenting later, 1269 pts (3.2% of total) randomized to 4 different thrombolytic regimens within 1 hr of symptom onset (mean 0.8±0.2 hr) were compared with 38,562 pts treated between 1 and 6 hrs (mean 3.2±1.6 hr) in GUSTO.<1 hr1-6 hr<1 hr1-6 hrAge (yrs)60.160.9Killip 3 or 4 (%)2.12.0Male(%)78.874.8Systolic BP (mm)127129Prior Angina (%)46.436.5Pulse (bpm)7575Prior MI (%)20.716.1Anterior MI (%)4339Pts receiving thrombolysis early (<1 hr) in the course of MI did not differ substantially with regard to severity of MI or any baseline clinical parameter from those presenting 1–6 hrs after symptom onset, except for a trend toward more frequent prior angina in the <1 hr group. Mortality (30-day) was 9% lower among the first hour pts (and not different between t-PA and SK groups) than among those treated later, comparable to the overall 14% mortality reduction by t-PA compared with SK in the main trial. Thus, despite the apparent existence of a “golden first hour” during early reperfusion trials, outcome following thrombolysis during the first hour in GUSTO was only modestly better than among patients treated later