High incidence of TIMI flow 0 to I in patients with ST-elevation myocardial infarction without electrocardiographic lytic criteria

Background Most patients with ST-elevation myocardial infarction fulfilling ST-segment elevation (STE) lytic criteria present an occluded culprit artery but the occlusion rate in those with minimal STE (minSTE) not fulfilling lytic criteria is unknown. Methods In 63 patients with minSTE (mean STE:1.2 ± 0.6 mm) and 149 with lytic STE criteria (lyticSTE, 4.8 ± 3.1 mm), an emergency coronary angiography was performed, serial creatine kinase–MB was determined, and ejection fraction was measured by 2-dimensional echocardiography. Results The 2 groups showed similar time from pain onset to electrocardiogram (minSTE 196 ± 199 vs lyticSTE, 176 ± 172 min, P = .444), and although time to catheterization was longer in patients with minSTE (426 ± 314 vs 253 ± 239 min, P < .001), the rate of TIMI flow 0 to I (88% vs 81%, P = .21) was similar and percutaneous coronary intervention was performed in >80% of patients from the 2 groups. Moreover, patients with minSTE had higher rate of collateral circulation (27% vs 13%, P = .013), lower rate of Q waves (44% vs 60%, P = .041), lower creatine kinase–MB (202 ± 150 vs 335 ± 280, μg/L, P < .001), higher ejection fraction (54% ± 9% vs 49% ± 12%, P = .004), and lower mortality (0% vs 7.4%, P = .036). Conclusions ST-elevation myocardial infarction patients with minSTE present a high prevalence of TIMI flow 0 to I similar to those meeting lyticSTE suggesting an identical underlying mechanism and the potential to benefit from primary angioplasty.