Background: The significance of ST-segment depression in acute coronary syndrome has been the subject of debate for many decades. Studies indicate that different manifestations of ST/T changes may have significantly different prognostic implications.
Methods and results: We studied the correlation of ST/T changes in 12-lead electrocardiography recorded during pain, to clinical and angiographic findings and in-hospital prognosis, in patients with non-ST-elevation acute coronary syndrome and elevated troponin levels. Fifty consecutive patients could be differentiated into two groups: (1) 25 patients with ST-segment depression and a negative T wave maximally in leads V4-5, (2) 25 patients with ST-segment depression and a positive T wave in the precordial lead with maximal ST-segment depression. Patients in group I had significantly more often left main or left main equivalent coronary artery disease; 76% versus 8% (P < 0.001), heart failure; 40% versus 4% (P = 0.005), and higher in-hospital mortality; 24% versus 0% (P = 0.02), than patients in group II. The troponin levels did not differ significantly between the groups.
Conclusions: In patients with non-ST-elevation acute coronary syndrome and elevated troponin levels two subgroups could be identified. Transient ST-segment depression and a negative T wave maximally in leads V4-5 during anginal pain predicts left main, left main equivalent, or severe three-vessel coronary artery disease with high sensitivity and specificity. In patients with ST-segment depression and a positive T wave, there is a high probability of one-vessel disease.