The DANAMI-2 trial showed a 40% decrease in the composite end point with primary coronary angioplasty versus fibrinolysis. This result was primarily driven by a decrease in reinfarction, with no significant difference in mortality or stroke rates. The objective of this study was to determine the prognostic value of the sum ST-segment elevation (∑ST↑) on baseline electrocardiography in patients who were randomized to receive primary coronary angioplasty versus fibrinolysis. In the DANAMI-2, 1,450 patients had baseline ST-segment deviation measurements and were assigned to quartiles according to ∑ST↑: 0 to 6.5, 7.0 to 9.5, 10.0 to 14.5, and 15.0 to 70.5 mm. The composite and component end-point rates at 30 days were determined for each quartile and chi-square for trend statistic was used to compare end-point rates across quartiles of ∑ST↑. The composite end point occurred more often with increasing ∑ST↑ (p = 0.05). With regard to component end points, only mortality increased significantly with ∑ST↑ (p = 0.03), whereas reinfarction and stroke rates did not. By multivariate analysis, only ∑ST↑ and age were independent predictors of mortality. The relative benefit of primary coronary angioplasty was similar for all ∑ST↑ quartiles. In conclusion, the magnitude of ∑ST↑ correlates with increased mortality at 30 days, thus driving the composite end point rate. Regardless of ∑ST↑, patients had a lower composite end-point rate with primary coronary angioplasty than with fibrinolysis.