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

Abstract

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.