Long-term prognostic value of ejection fraction changes during dobutamine-atropine stress echocardiography

Dobutamine stress echocardiography (DSE), using subjective wall motion scoring, provides incremental prognostic information over clinical data. The aim of the study was to test the additional prognostic value of left ventricular ejection fraction (LVEF) changes during DSE at different stages.

The study population comprised 106 consecutive patients (mean age 60+/-11 years, 73% men) with suspected or known coronary artery disease referred for DSE. Stress-induced ischemia was defined as new or worsening wall motion abnormalities. LVEF was measured at rest, peak stress and recovery. Follow-up was successful in 104 (98%) patients. Four patients who underwent revascularization within 60 days were excluded from the analysis. End-points during follow-up were cardiac death, non-fatal myocardial infarction and late revascularization.

During a mean follow-up of 5.3+/-2.1 years, 26% of patients died: 13% due to cardiac death, 6% patients experienced non-fatal myocardial infarction and 38% underwent late revascularization. Rest-to-peak LVEF increase was lower in patients who experienced cardiac death or non-fatal myocardial infarction (4.9+/-8.6 compared with 9.2+/-7.5, P=0.04) and any cardiac events (6.0+/-8.5 compared with 10.5+/-6.7, P=0.004). An inverse correlation was found between left ventricular ejection increase and the number of ischemic segments (P<0.0001). A multivariable Cox proportional hazard model demonstrated that, in addition to clinical data and new wall motion abnormalities, lower LVEF increase had an incremental prognostic value in predicting hard cardiac events (hazard ratio 1.1, 95% confidence interval 1.0-1.2).

Failure of LVEF to significantly increase during DSE, denoting more extensive ischemia, identifies a higher-risk subgroup for late cardiac events.