Wall motion abnormalities with low-dose dobutamine predict a high risk of cardiac death in medically treated patients with ischemic cardiomyopathy

Abstract

BACKGROUND: Severe and extensive coronary artery disease is the underlying cause of stress-induced wall motion abnormalities (SWMA) with low-dose (10 microg/kg/min) dobutamine suggesting that these abnormalities may identify those with poor outcome. HYPOTHESIS: We assessed the prognostic value of low-dose SWMA in medically treated patients with ischemic cardiomyopathy. METHODS: Low- and peak-dose dobutamine echocardiography was performed in 235 patients with ischemic cardiomyopathy (ejection fraction 31% +/- 8%) who were treated with medical therapy. The survival of patients with low-dose SWMA (n = 33) was compared with the survival of patients without ischemia (n = 85) and those with peak-dose SWMA (n = 117). RESULTS: There were 123 cardiac deaths (52%) during follow-up of 4.1 +/- 3.3 years. Multivariate predictors of cardiac death were age (p = 0.002, hazard ratio [HR]: 1.03), diabetes (p = 0.028, HR: 1.54), New York Heart Association (NYHA) class III, IV heart failure (p = 0.001, HR: 1.94), the presence of peak dose SWMA (p < 0.001, HR: 2.59), and low-dose SWMA (p = 0.005, HR: 2.28). Survival of patients without ischemia was significantly better than those with peak-dose SWMA (p < 0.0001) and those with low-dose SWMA (p = 0.001). The survival of patients with low-dose SWMA was the same as those with peak-dose SWMA (p = 0.89). CONCLUSIONS: Low-dose SWMA is an independent predictor of cardiac mortality in medically treated patients with ischemic cardiomyopathy. Patients with low-dose SWMA are at equivalent risk to those with peak-dose SWMA.