Dobutamine-atropine stress echocardiography for risk stratification in patients with chronic left ventricular dysfunction.

OBJECTIVE To assess the prognostic value of sustained improvement, scar and inducible ischemia with or without viability in patients with chronic left ventricular dysfunction (LVD). BACKGROUND Dobutamine-atropine stress echocardiography (DASE) accurately detects scar, reversible dysfunction and the extent of coronary artery disease in LVD. METHODS Three hundred fifty consecutive patients (age 62+/-13 years, mean+/-SD, 215 men/135 women) with moderate to severe LVD (LVEF < 40%, mean 30+/-8%) underwent DASE and were followed for > or =18 months. Dobutamine-atropine stress echocardiographic findings were classified according to sustained improvement in all vascular territories, scar, inducible ischemia (worsening wall motion at peak dose only or biphasic responses) and their extent. RESULTS Sustained improvement occurred in 83 patients (24%), scar alone in 99 (28%) and inducible ischemia in 168 (48%, with biphasic responses in 104). Ischemia was induced in all vascular territories in 26 patients. Patients with sustained improvement or scar alone were treated medically, whereas 46% (78/168) with inducible ischemia were revascularized (coronary bypass surgery, n = 67 or angioplasty, n = 11). There were 76 hard events including cardiac death in 59, nonfatal myocardial infarction in 11, and resuscitated sudden death in 6. Hard events were rare in sustained improvement (5%, 4/83), uncommon in scar (13%, 13/99) and common (p < 0.01) in medically treated patients with inducible ischemia (59%, 53/90). Cardiac deaths were especially common (p < 0.01) in patients with biphasic responses (55%, 28/51). Inducible ischemia independently predicted hard events (chi2 = 75.35, p < 0.001) along with reduced LVEF at peak dose (chi2 = 8.38, p = 0.004). Hard cardiac events were uncommon (8%, 6/78, p < 0.001) in patients with inducible ischemia who underwent early revascularization. CONCLUSIONS Inducible ischemia during DASE was the major determinant of outcome in LVD and independent of clinical data and left ventricular function. Improved wall thickening alone and scar alone predicted good outcome. Survival of patients with inducible ischemia was better after revascularization.