title: Clinical significance of abnormal T waves in patients with non-ST-segment elevation acute coronary syndromes.
abstract: T-wave abnormalities are common electrocardiographic occurrences in patients with non-ST-segment elevation acute coronary syndromes. Although these abnormalities are considered relatively benign, physicians use them to guide therapies. The study objective was to examine the prognostic predictive information of T-wave abnormalities in the setting of unstable coronary artery disease. The T-wave abnormality criterion was based on a new set of normal T-wave amplitude limits differentiated by gender, age, electrocardiographic lead, and QRS axis. Four hundred sixty-eight patients suspected of an acute ischemic incident and considered ineligible for reperfusion therapy were included. Thirteen categories of T-wave abnormalities were tested prospectively. The primary 30-day end point was the combination of refractory angina, myocardial infarction, or death. Quantitative T-wave analysis in an electrocardiographic core laboratory revealed 6 of 13 prespecified categories of T-wave abnormalities that were significantly associated with an adverse outcome. T-wave abnormalities had no prognostic value when ST-segment depression was also present, but this occurred in only 7.9% of patients. T-wave abnormalities as the sole manifestation of ischemia were common (74.4%). Patients with abnormal T waves in > or =1 of 6 selected abnormality categories (70.3%) had a significantly higher risk of death, acute myocardial infarction, and refractory angina (11% vs 3%; p = 0.018). Thus, T-wave abnormalities in patients presenting with non-ST-segment elevation acute coronary syndromes are common and should not automatically be regarded as benign phenomena. Quantitative T- wave analysis provides optimal risk stratification.
authors.affiliation: The Heart Center, Department of Medicine, Copenhagen University Hospital, Copenhagen, Denmark. mdiloujacobsen@dadlnet.dk
authors.forename: M D
authors.initials: MD
authors.lastname: Jacobsen
authors.forename: G S
authors.initials: GS
authors.lastname: Wagner
authors.forename: L
authors.initials: L
authors.lastname: Holmvang
authors.forename: P W
authors.initials: PW
authors.lastname: Macfarlane
authors.forename: U
authors.initials: U
authors.lastname: Näslund
authors.forename: P
authors.initials: P
authors.lastname: Grande
authors.forename: P
authors.initials: P
authors.lastname: Clemmensen
mesh_terms: D000368:Aged; D000789:Angina, Unstable / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic; D012008:Recurrence; D015996:Survival Rate