Event‐free survival in patients after an acute coronary event with exercise‐induced normalization of the T‐wave

Background: Risk stratification of patients with unstable angina or non‐Q‐wave myocardial infarction (MI) is an unresolved clinical problem. The prognostic value of T‐wave normalization (TWN) during exercise has not been studied in this group of patients. Hypothesis: Event‐free survival in clinically stable patients after an acute coronary event without ST‐segment elevation can be predicted by the presence of exercise‐induced TWN. Methods: Sixty‐five patients (43 men and 22 women, mean age 62 ± 10 years) entered the study. The diagnosis of unstable angina and non‐Q‐wave MI was made in 40 and 25 patients, respectively. A treadmill exercise test was performed in all patients after clinical stabilization. The patients were divided into three groups: those with negative baseline T waves and exercise‐induced TWN (Group 1); those with negative baseline T waves, but without TWN (Group 2); and those with positive baseline T waves (Group 3). The patients were followed up for 6 months. Results: During follow‐up, serious cardiovascular complications occurred in 15 (23%) patients. These included exacerbation of ischemic heart disease (14 patients) and acute MI (1 patient). Event‐free survival was greater in patients in Group 1 (95%) than in those in Group 2 (68%, p < 0.034) or Group 3 (71%, NS). Among all patients studied, exercise‐induced TWN was predictive of event‐free survival with a sensitivity of 38% and a specificity of 93%. Conclusions: In clinically stable patients after an acute coronary event without ST‐segment elevation, exercise‐induced TWN is a specific but not sensitive predictor of event‐free survival after 6 months.