Ischemic st-segment depression maximal in v1–v4 (Versus v5–v6) of any amplitude is specific for occlusion myocardial infarction (versus nonocclusive ischemia)

BACKGROUND: Occlusion myocardial infarctions (OMIs) of the posterolateral walls are commonly missed by ST-segment– elevation myocardial infarction (STEMI) criteria, with >50% of patients with circumflex occlusion not receiving emergent rep-erfusion and experiencing increased mortality. ST-segment depression maximal in leads V1–V4 (STDmaxV1– 4) has been suggested as an indicator of posterior OMI. METHODS AND RESULTS: We retrospectively reviewed a high-risk population with acute coronary syndrome. OMI was defined from prior studies as a culprit lesion with TIMI (Thrombolysis in Myocardial Infarction) 0 to 2 flow or TIMI 3 flow plus peak troponin T >1.0 ng/mL or troponin I >10 ng/mL. STEMI was defined by the Fourth Universal Definition of Myocardial Infarction. ECGs were interpreted blinded to outcomes. Among 808 patients, there were 265 OMIs, 108 (41%) meeting STEMI criteria. A total of 118 (15%) patients had “suspected ischemic” STDmaxV1– 4, of whom 106 (90%) had an acute culprit lesion, 99 (84%) had OMI, and 95 (81%) underwent percutaneous coronary intervention. Suspected ischemic STDmaxV1– 4 had 97% specificity and 37% sensitivity for OMI. Of the 99 OMIs detected by STDmaxV1– 4, 34% had <1 mm ST-segment depression, and only 47 (47%) had accompanying STEMI criteria, of which 17 (36%) were identified a median 1.00 hour earlier by STDmaxV1– 4 than STEMI criteria. Despite similar infarct size, TIMIS flow, and coronary interventions, patients with STEMI(−) OMI and STDmaxV1– 4 were less likely than STEMI(+) patients to undergo catheterization within 90 minutes (46% versus 68%; P=0.028). CONCLUSIONS: Among patients with high-risk acute coronary syndrome, the specificity of ischemic STDmaxV1– 4 was 97% for OMI and 96% for OMI requiring emergent percutaneous coronary intervention. STEMI criteria missed half of OMIs detected by STDmaxV1– 4. Ischemic STDmaxV1–V4 in acute coronary syndrome should be considered OMI until proven otherwise.