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 (SigmaST) 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 SigmaST: 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 SigmaST. The composite end point occurred more often with increasing SigmaST (p = 0.05). With regard to component end points, only mortality increased significantly with SigmaST (p = 0.03), whereas reinfarction and stroke rates did not. By multivariate analysis, only SigmaST and age were independent predictors of mortality. The relative benefit of primary coronary angioplasty was similar for all SigmaST quartiles. In conclusion, the magnitude of SigmaST correlates with increased mortality at 30 days, thus driving the composite end point rate. Regardless of SigmaST, patients had a lower composite end-point rate with primary coronary angioplasty than with fibrinolysis.