文摘
We prospectively evaluated all patients admitted to our coronary care unit during 1993 with ischemic chest pain but without ST-segment elevation on the presenting electrocardiogram, and determined the influence of the extent of ST-segment depression, measured using calipers and blinded to the outcome, on 4-year survival. The presenting symptoms of 367 patients (mean age 64 years) were coded according to the Braunwald classification, 86 % being in class IIIB (primary unstable angina with rest angina within 48 hours) and 7.4 % in class IIIC (postinfarction angina). Thirty-two patients (8.6 % ) had myocardial infarction at presentation (defined as a creatine kinase level exceeding twice the reference range within 18 hours). During hospitalization 97 % of patients received aspirin, 67 % received intravenous heparin, 37 % underwent angiography, and 35 % underwent revascularization. The vital status of 99 % of the patients was determined after a median of 52 months (interquartile range 48 to 55). At follow-up, 88 % of patients were taking aspirin, 45 % were taking β blockers, and 50 % had undergone revascularization. The survival rate was 70 % in patients with ≥0.5-mm ST-segment depression (53 % , 77 % , and 82 % survival for ≥2-, 1-, and 0.5-mm ST-segment depression, respectively; p <0.0001). Patients with a normal electrocardiogram had a greater survival rate (94 % ) than that of patients with 0.5-mm ST-segment depression (82 % , p = 0.020), but not significantly different from that of patients with T-wave inversion (84 % , p = NS). Independent predictors of mortality (odds ratio [95 % confidence interval]) were: age in yearly increments (1.05 [1.03 to 1.06], p = 0.003), revascularization during follow-up (0.40 [0.29 to 0.56], p = 0.006), pulmonary edema (3.45 [2.19 to 5.45], p = 0.007), and ST-segment depression (1.37 [1.20 to 1.55], p = 0.015). Thus, ST-segment depression of ≥0.5 mm predicts 4-year survival in patients with acute ischemic syndromes.