Prognostic significance of baseline ST-T-wave abnormalities in diagnostic stress echocardiography.

OBJECTIVE

The aim of this study was to determine whether resting ST-T wave abnormalities (ST-Ta) provide incremental prognostic information in patients with no history of coronary artery disease undergoing dobutamine stress echocardiography (DSE).

METHODS

We evaluated 1308 consecutive patients without previous myocardial infarction (MI) or revascularization who underwent DSE. Ischemia was defined as new or worsening wall motion abnormalities. End points during follow-up were all-cause death and cardiac death/nonfatal MI.

RESULTS

ST-Ta were detected in 162 (12%) patients. The incidence of ischemia was higher in patients with baseline ST-Ta than patients without [74 (46%) vs. 327 (28%), P=0.00001]. During a follow-up of 4.6 ± 3 years, cardiac death/nonfatal MI occurred in 42 (26%) patients with resting ST-Ta and in 157 (14%) patients without resting ST-Ta (P<0.001). Patients with ST-Ta had a higher annual cardiac death/nonfatal MI rate compared with patients without, both in the presence of normal DSE (3.2 vs. 1.4%, P=0.01) as well as abnormal DSE (5.3 vs. 3%, P<0.001). In a Cox proportional modeling, resting ST-Ta added incremental value over clinical and stress echocardiographic data for the prediction of death (global χ 125, 140, 150, respectively; P<0.05) and cardiac death/nonfatal MI (global χ 79, 100, 111, respectively; P<0.05).

CONCLUSION

Baseline ST-Ta are associated with an increased risk of cardiac death/nonfatal MI and all-cause mortality, incremental to clinical data and DSE results. The associated risk is persistent among patients with normal DSE.